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OpenSpace/tests/SpiceTest/spicekernels/cas_v37.tf
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HCL

KPL/FK
Cassini Spacecraft Frame Definitions Kernel
==============================================================================
This frame kernel contains the Cassini spacecraft, science instrument, and
communication antennae frame definitions.
Version and Date
----------------------------------------------------------
The TEXT_KERNEL_ID stores version information of loaded project text
kernels. Each entry associated with the keyword is a string that consists
of four parts: the kernel name, version, entry date, and type. For example,
the ISS I-kernel might have an entry as follows:
TEXT_KERNEL_ID += 'CASSINI_ISS V0.0.0 29-SEPTEMBER-1999 IK'
| | | |
| | | |
KERNEL NAME <-------+ | | |
| | V
VERSION <-------+ | KERNEL TYPE
|
V
ENTRY DATE
Cassini Frame Kernel Version:
\begindata
TEXT_KERNEL_ID += 'CASSINI_FRAMES V3.7.0 20-NOVEMBER-2003 FK'
\begintext
Version 3.7 -- November 20, 2003 -- Lee Elson
-- Updated CASSINI_XBAND per Diane Conner's request email. This
was done by modifying the CASSINI_KABAND boresight vector.
See [48] for details.
Version 3.6 -- April 18, 2003 -- Lee Elson
-- Modified CASSINI_XBAND frame definition so that its values
are the same as CASSINI_KABAND. Added a new frame called
CASSINI_XBAND_TRUE (NAIF ID -82108) that has the same
definition parameters as the old CASSINI_XBAND. Also modified
text structure so that changes are dated and stand out better
for the human reader. See [46] and [47] for details.
-- Modified descriptive text structure so that changes are dated
and stand out better for the human reader.
Version 3.5 -- September 4, 2002 -- Scott Turner, Richard West, and Rick
McCloskey
-- Entries for CASSINI_VIMS_IR_SOL, CASSINI_RADAR_2, and
CASSINI_RADAR_4 were updated to reflect current values. See
[42], [43], and [44] for details.
-- CASSINI_VIMS_IR_SOL is now referenced directly to the
spacecraft frame, CASSINI_SC_COORD, rather than
CASSINI_VIMS_IR.
Version 3.4 -- June 11, 2002 -- Scott Turner and Joshua Colwell
-- Entries for CASSINI_KABAND were updated per Diane Conner's
request email. See [38] for details.
-- Updated entries for CASSINI_CIRS_FPB, CASSINI_CIRS_FP1,
CASSINI_CIRS_FP3, and CASSINI_CIRS_FP4 based on updated
alignment information provided in ECR 100515. See [39] for
details.
-- Modified the entries for CASSINI_UVIS_HSP, CASSINI_UVIS_FUV,
and CASSINI_UVIS_EUV to match the body vector table provided
by Alain Jouchoux in May 3, 2002 e-mail. This same data set
is in the CASPER UVIS definition file. Verified that CASPER
and PDT give consistent results using this frame kernel.
-- Updated the entry for CASSINI_VIMS_IR to match the body
vector table entry provided by Rick McCloskey. See [41] for
details.
Version 3.3 -- February 20, 2002 -- Scott Turner
-- Updated the frame entry and documentation for
CASSINI_VIMS_RAD as a result of ECR 101029 and documentation
submitted with it. See [36] for details.
Version 3.2 -- January 22, 2002 -- Scott Turner
-- Updated frame entries for CASSINI_XBAND and CASSINI_KABAND as
a result of SCR 490. See [35] for details.
Version 3.1 -- August 9, 2001 -- Scott Turner
-- Updated frame entries for CASSINI_XBAND and CASSINI_KABAND as
a result of SCR 468. See [34] for details.
Version 3.0 -- April 23, 2001 -- Scott Turner
-- Restructured the articulating frames: CASSINI_MIMI_LEMMS1,
CASSINI_MIMI_LEMMS2, CASSINI_CDA, CASSINI_CAPS. They now
allow for multiple paths from the instrument frames to the
spacecraft frame depending on what C-kernels are available.
Use caution when loading conflicting C-kernels.
-- Renamed CASSINI_SRU to CASSINI_SRU-A and added CASSINI_SRU-B,
CASSINI_SRU-A_RAD, and CASSINI_SRU-B_RAD.
-- Added the CASSINI_UVIS_SOLAR frame definition to support the
UVIS solar occultation port FOV.
-- Removed CASSINI_UVIS_EUV_OCC and CASSINI_UVIS_FUV_OCC frame
definitions since the FOVs they support are actually tied to
CASSINI_UVIS_EUV and CASSINI_UVIS_FUV frames respectively.
-- Added the CASSINI_VIMS_IR_SOL frame definition to support the
IR channel solar port FOV.
Version 2.9 -- November 16, 2000 -- Scott Turner
-- Corrected the definition of CASSINI_MIMI_INCA to account for
the 9.5 degree offset from the spacecraft -Y axis.
-- Corrected the definition of CASSINI_INMS. The Z-axis of this
frame is now co-aligned with the -X axis of CASSINI_SC_COORD.
Version 2.8 -- October 9, 2000 -- Scott Turner
-- Updated CASSINI_ISS_NAC and CASSINI_ISS_WAC to reflect the
updates associated with the Fomalhaut images taken on
September 18, 2000.
-- Migrated the CASSINI_ISS_NAC_RAD, CASSINI_ISS_WAC_RAD,
CASSINI_VIMS_RAD, CASSINI_CIRS_RAD, CASSINI_CAPS,
CASSINI_CDA, CASSINI_INMS, CASSINI_MAG_PLUS,
CASSINI_MAG_MINUS, CASSINI_MIMI_CHEMS, CASSINI_MIMI_INCA,
CASSINI_MIMI_LEMMS1, CASSINI_MIMI_LEMMS2, CASSINI_RADAR_1,
CASSINI_RADAR_2, CASSINI_RADAR_3, CASSINI_RADAR_4,
CASSINI_RADAR_5, CASSINI_RPWS, CASSINI_RPWS_EXPLUS,
CASSINI_RPWS_EXMINUS, CASSINI_EZPLUS, CASSINI_RPWS_LP,
CASSINI_KUBAND, and CASSINI_SBAND frames from the prototype
section.
-- Updated CASSINI_XBAND and CASSINI_KABAND as the result of SCR
367. These frames were migrated from the prototype section as
well.
Version 2.7 -- July 7, 2000 -- Scott Turner
-- Added the following frame entries RPWS requested:
CASSINI_RPWS_EXPLUS, CASSINI_RPWS_EXMINUS,
CASSINI_RPWS_EZPLUS, CASSINI_RPWS_LP to the prototype frame
section. See [14] for details.
-- Changed the following frame names: CASSINI_HGA_X ->
CASSINI_XBAND, CASSINI_HGA_S -> CASSINI_SBAND, CASSINI_HGA_KA
-> CASSINI_KABAND, CASSINI_HGA_KU -> CASSINI_KUBAND.
-- Halved the Euler angles associated with the CASSINI_CIRS_FP3
and CASSINI_FP4 frames. See [15] for details.
Version 2.6 -- June 26, 2000 -- Scott Turner
-- The RSS frame entries in the prototype section were renamed
to HGA based frames.
-- Removed the CASSINI_MAG frame and replaced it with the
CASSINI_MAG_PLUS and CASSINI_MAG_MINUS frames.
Version 2.5 -- April 2, 2000 -- Scott Turner
-- Added CASSINI_VIMS.
-- Added CASSINI_UVIS_FUV, CASSINI_UVIS_EUV,
CASSINI_UVIS_FUV_OCC, CASSINI_UVIS_EUV_OCC, CASSINI_UVIS_HSP,
and CASSINI_UVIS_HDAC.
-- Fixed the keywords defining the CASSINI_HGA frame to use the
proper ID code, -82101.
-- Updated CASSINI_ISS_NAC and CASSINI_ISS_WAC to reflect the
latest boresight information available in ECR's 100078 and
100079.
Version 2.4 -- March 27, 2000 -- Scott Turner
-- Added the CIRS Focal Plane Boresight frame, CASSINI_CIRS_FPB.
-- CASSINI_CIRS_FP1, CASSINI_CIRS_FP3, CASSINI_CIRS_FP2 are no
longer relative to CASSINI_SC_COORD but to the intermediate
frame CASSINI_CIRS_FPB.
-- Migrated the CASSINI_UVIS frame from the prototype section
and added the CASSINI_UVIS_OCC frame.
-- Added the TEXT_KERNEL_ID keyword to make version information
accessible to programs at runtime.
Version 2.3 -- March 9, 2000 -- Scott Turner
-- Updated the Euler angles for CASSINI_CIRS_FP1,
CASSINI_CIRS_FP3, and CASSINI_CIRS_FP4. Migrated them from
the prototype section into the CIRS Section of the FK.
Version 2.2 -- September 10, 1999 -- Scott Turner
-- Removed TKFRAME_[ID]_BORESIGHT keyword for all but the
antenna frames present. This information can now be found in
the instrument kernel with the keyword: INS[ID]_BORESIGHT.
-- Added a frame for the Stellar Reference Unit (SRU).
-- Added prototype frame entries for several instruments. The
transformations stored here for these frames are NOT for any
real calculations, and in some cases are not connected with
the actual instrument pointing at all. These frames will
migrate from the prototype section as the kernel evolves.
-- Changed CASSINI_SC_BUS to CASSINI_SC_COORD.
-- Changed the LGA frame name definitions to CASSINI_LGA1 and
CASSINI_LGA2 to accomodate simple translation to flight
software frame names.
-- Changed NAC and WAC ID codes from -82010 and -82020 to -82360
and -82361 respectively. This is to conform to the new ID
code scheme proposed by Jeff Boyer.
-- Altered the textual description of the spacecraft coordinate
system to conform with [8].
-- Added some text from [8] to the ISS_NAC frame description.
Version 2.1 -- July 14, 1999 -- Scott Turner
-- Fixed incorrect comments regarding the NAC images.
-- Fixed an improperly specified transformation for LGA2.
-- Added TKFRAME_[ID]_BORESIGHT keyword for the frames present.
Version 2.0 -- May 5, 1999 -- Scott Turner
-- Added ISS NAC and WAC instrument frames.
Version 1.0 -- May 14, 1998 -- Jeff Bytof
-- Initial Release.
References
----------------------------------------------------------
1. ``C-kernel Required Reading''
2. ``Kernel Pool Required Reading''
3. ``Frames Required Reading''
4. Cassini spacecraft blueprints. Provided by Kevin Tong, JPL.
5. ``Cassini Science Instruments and Investigations'', Revised
Second Printing. Stephen J. Edberg.
6. ``Determination of the ISS Boresights in Cassini Spacecraft
Coordinate System.'' Carolyn Porco and Vance Haemmerle.
7. Email from Vance Haemmerle regarding WAC alignment.
8. Cassini Document No. 699-406 ``Project Guidance Analysis
Book''
9. CASPER CIRS I-kernel Version 3.2
10. CIRS Fields-of-View PDF attached in an email from Stephen
Edberg to Diane Conner.
11. Cassini Engineering Change Request #100078
12. Cassini Engineering Change Request #100079
13. CASPER VIMS I-kernel Version Version 4.2
14. Email from Terry Averkamp regarding new RPWS frame entries.
15. Email from Richard Achterberg regarding the CIRS frame
entries.
16. Email from Vance Haemmerle regarding the Fomalhaut updates to
the ISS NAC and WAC alignments.
17. Email from Jeff Boyer regarding radiator boresight
alignments, MIMI_CHEMS orientation, and RPWS orientation.
18. Email from Sascha Kempf regarding CDA articulation.
19. CASPER INMS I-kernel Version 5.0
20. Email from Marcia Burton regarding the MAG field of views and
frame definitions.
21. CASPER MAG I-kernel Version 6.0
22. CASPER MIMI I-kernel Version 4.0
23. CASPER RADAR I-kernel Version 2.2
24. Email from Terry Averkamp discussing the new RPWS frame
entries.
25. Email from Thomas Burk regarding the updates to CASSINI_XBAND
and CASSINI_KABAND frames that were the result of SCR 367.
26. Email from Deborah Bass regarding a correct in the
CASSINI_INMS frame definition.
27. Email from Donald Mitchell regarding a correction in the
CASSINI_MIMI_INCA frame definition.
28. Email from Rick McCloskey regarding updates and additions to
the VIMS frame set.
29. Email from Joshua Colwell regarding the CASSINI_UVIS_SOLAR
frame definition.
30. Email from Joshua Colwell verifying the CASSINI_UVIS_SOLAR
frame definition.
31. Email from Rick McCloskey confirming the CASSINI_VIMS_V,
CASSINI_VIMS_IR, CASSINI_VIMS_IR_SOL frame definitions.
32. Email from Jeff Boyer providing CASSINI_SRU_RAD frame
definition.
33. Email from Don Mitchell describing the CASSINI_MIMI_LEMMS1
and CASSINI_MIMI_LEMMS2 articulation characteristics.
34. Email from Trina Ray describing updates for the CASSINI_XBAND
and CASSINI_KABAND frame definitions.
35. Email from Diane Conner describing updates for the
CASSINI_XBAND and CASSINI_KABAND boresights.
36. Cassini ECR 101029 - Change CASSINI_VIMS_RAD frame
definition.
37. Cassini ECR 10325-B -- Change VIMS Sun Viewing Constraints
Flight Rule FF37B2.
38. Email from Diane Conner regarding CASSINI_KABAND updated
boresight information.
39. Page 28 from ECR 100515 listing updated alignment information
for CASSINI_CIRS detectors.
40. Joshua Colwell's updated version 3.3.1 Cassini Spacecraft
Frame Definition kernel.
41. Email from Rick McCloskey regarding the values in the body
vector table for CASSINI_VIMS_IR.
42. Email from Rick McCloskey regarding the Euler angles for
CASSINI_VIMS_IR_SOL, the VIMS solar port.
43. Email correction from Rick McCloskey regarding the Euler
angles for CASSINI_VIMS_IR_SOL.
44. Email from Richard West regarding the CASSINI_RADAR_2 and
CASSINI_RADAR_4 Euler angles.
45. Spreadsheet (gnumeric format) from Rick McCloskey regarding
the Euler angles for CASSINI_VIMS_IR_SOL.
46. Email from Nicole Rappaport outlining needed changes to frame
and radio science instrument kernel due to project use of Ka
band data for X band pointing.
47. Cassini ECR number 102788 -- Additional Frame and FOV
definitions to SPICE FK & IK Files for RSS
48. Cassini R/SCR NO: 613 -- Update the Onboard XBAND body vector
table entries for GWE#3
Contact Information
----------------------------------------------------------
Direct questions, comments, or concerns about the contents of this kernel
to:
Lee Elson, NAIF/JPL, (818)-354-4223, Lee.Elson@jpl.nasa.gov
Implementation Notes
----------------------------------------------------------
This file is used by the SPICE system as follows: programs that make use of
this frame kernel must `load' the kernel, normally during program
initialization. Loading the kernel associates data items with their names
in a data structure called the `kernel pool'. The SPICELIB routine LDPOOL
loads a kernel file into the pool as shown below:
CALL LDPOOL ( frame_kernel_name )
In order for a program or subroutine to extract data from the pool, the
SPICELIB routines GDPOOL and GIPOOL are used. See [2] for more details.
This file was created and may be updated with a text editor or word
processor.
Note: the keyword TKFRAME_[ID]_BORESIGHT defines the instrument or antenna
boresight axis in the instrument or antenna frame.
Cassini Frames
----------------------------------------------------------
The following Cassini frames are defined in this kernel file:
Frame Name Relative To Type NAIF ID
======================= =================== ======= =======
AACS Body Frame:
----------------
CASSINI_SC_COORD J2000 CK -82000
CASSINI_SRU-A CASSINI_SC_COORD FIXED -82001
CASSINI_SRU-B CASSINI_SC_COORD FIXED -82002
CASSINI_SRU-A_RAD CASSINI_SC_COORD FIXED -82008
CASSINI_SRU-B_RAD CASSINI_SC_COORD FIXED -82009
Antenna Frames (-821xx):
------------------------
CASSINI_HGA CASSINI_SC_COORD FIXED -82101
CASSINI_LGA1 CASSINI_SC_COORD FIXED -82102
CASSINI_LGA2 CASSINI_SC_COORD FIXED -82103
CASSINI_XBAND CASSINI_SC_COORD FIXED -82104
CASSINI_KABAND CASSINI_SC_COORD FIXED -82105
CASSINI_KUBAND CASSINI_SC_COORD FIXED -82106
CASSINI_SBAND CASSINI_SC_COORD FIXED -82107
CASSINI_XBAND_TRUE CASSINI_SC_COORD FIXED -82108
ISS Frames (-8236x):
------------------------
CASSINI_ISS_NAC CASSINI_SC_COORD FIXED -82360
CASSINI_ISS_WAC CASSINI_SC_COORD FIXED -82361
CASSINI_ISS_NAC_RAD CASSINI_SC_COORD FIXED -82368
CASSINI_ISS_WAC_RAD CASSINI_SC_COORD FIXED -82369
CIRS Frames (-8289x):
------------------------
CASSINI_CIRS_FP1 CASSINI_CIRS_FPB FIXED -82890
CASSINI_CIRS_FP3 CASSINI_CIRS_FPB FIXED -82891
CASSINI_CIRS_FP4 CASSINI_CIRS_FPB FIXED -82892
CASSINI_CIRS_FPB CASSINI_SC_COORD FIXED -82893
CASSINI_CIRS_RAD CASSINI_SC_COORD FIXED -82898
UVIS Frames (-8284x):
------------------------
CASSINI_UVIS_FUV CASSINI_SC_COORD FIXED -82840
CASSINI_UVIS_EUV CASSINI_SC_COORD FIXED -82842
CASSINI_UVIS_SOLAR CASSINI_SC_COORD FIXED -82843
CASSINI_UVIS_HSP CASSINI_SC_COORD FIXED -82844
CASSINI_UVIS_HDAC CASSINI_SC_COORD FIXED -82845
VIMS Frames (-8283x):
------------------------
CASSINI_VIMS_V CASSINI_SC_COORD FIXED -82370
CASSINI_VIMS_IR CASSINI_SC_COORD FIXED -82371
CASSINI_VIMS_IR_SOL CASSINI_SC_COORD FIXED -82372
CASSINI_VIMS_RAD CASSINI_SC_COORD FIXED -82378
CAPS Frames (-8282x):
------------------------
CASSINI_CAPS_BASE CASSINI_SC_COORD FIXED -82822
CASSINI_CAPS_ART CASSINI_CAPS_BASE CK -82821
CASSINI_CAPS CASSINI_CAPS_ART CK -82820
CASSINI_SC_COORD CK -82820
CDA Frames (-8279x):
------------------------
CASSINI_CDA_BASE CASSINI_SC_COORD FIXED -82792
CASSINI_CDA_ART CASSINI_CDA_BASE CK -82971
CASSINI_CDA CASSINI_CDA_ART CK -82790
CASSINI_SC_COORD CK -82790
INMS Frames (-8274x):
------------------------
CASSINI_INMS CASSINI_SC_COORD FIXED -82740
MAG Frames (-8235x):
------------------------
CASSINI_MAG_PLUS CASSINI_SC_COORD FIXED -82350
CASSINI_MAG_MINUS CASSINI_SC_COORD FIXED -82351
MIMI Frames (-8276x):
------------------------
CASSINI_MIMI_CHEMS CASSINI_SC_COORD FIXED -82760
CASSINI_MIMI_INCA CASSINI_SC_COORD FIXED -82761
CASSINI_MIMI_LEMMS_BASE CASSINI_SC_COORD FIXED -82765
CASSINI_MIMI_LEMMS_ART CASSINI_MIMI_LEMMS_BASE CK -82764
CASSINI_MIMI_LEMMS1 CASSINI_MIMI_LEMMS_ART CK -82762
CASSINI_SC_COORD CK -82762
CASSINI_MIMI_LEMMS2 CASSINI_MIMI_LEMMS_ART CK -82763
CASSINI_SC_COORD CK -82763
RADAR Frames (-8281x):
------------------------
CASSINI_RADAR_1 CASSINI_SC_COORD FIXED -82810
CASSINI_RADAR_2 CASSINI_SC_COORD FIXED -82811
CASSINI_RADAR_3 CASSINI_SC_COORD FIXED -82812
CASSINI_RADAR_4 CASSINI_SC_COORD FIXED -82813
CASSINI_RADAR_5 CASSINI_SC_COORD FIXED -82814
RPWS Frames (-8273x):
------------------------
CASSINI_RPWS CASSINI_SC_COORD FIXED -82730
CASSINI_RPWS_EXPLUS CASSINI_SC_COORD FIXED -82731
CASSINI_RPWS_EXMINUS CASSINI_SC_COORD FIXED -82732
CASSINI_RPWS_EZPLUS CASSINI_SC_COORD FIXED -82733
CASSINI_RPWS_LP CASSINI_SC_COORD FIXED -82734
where: the frame ID codes are built from the spacecraft ID code, the
instrument subsystem number, and the instrument number in a multiple
instrument subsystem. The numbers 8 and 9 are reserved for the radiators.
For example the ISS frame IDs are constructed as follows:
CASSINI_ISS_WAC ID = -82 36 1
| | |
| | |
SPACECRAFT ID CODE <-----+ | +----> INSTRUMENT NUMBER
|
V
INSTRUMENT SUBSYSTEM NUMBER
Cassini Frames Hierarchy
----------------------------------------------------------
Notes:
This diagram is subject to major revisions as this kernel evolves to suit
the needs of each instrument.
The articulating instrument frames have two paths back to the spacecraft
frame. The first is a direct path via a single C-kernel connecting the
instrument frame to the spacecraft frame. The second is one that utilizes a
fixed offset C-kernel to rotate the instrument frame into the articulation
frame, and then an articulation C-kernel and a base frame. For details see
the sections for CASSINI_CDA, CASSINI_CAPS, and CASSINI_MIMI_LEMMS.
The diagram below shows the Cassini frames hierarchy:
'IAU_EARTH' (EARTH BODY FIXED)
|
|<--- pck
|
'J2000' INERTIAL
|
|<--- ck
|
'CASSINI_SC_COORD'
|
'CASSINI_SRU-A'
|
'CASSINI_SRU-B'
|
'CASSINI_SRU-A_RAD'
|
'CASSINI_SRU-B_RAD'
|
'CASSINI_HGA'
|
'CASSINI_XBAND'
|
'CASSINI_KABAND'
| |
| 'CASSINI_XBAND_TRUE'
|
'CASSINI_KUBAND'
|
'CASSINI_SBAND'
|
'CASSINI_LGA1'
|
'CASSINI_LGA2'
|
'CASSINI_ISS_NAC'
|
'CASSINI_ISS_WAC'
|
'CASSINI_ISS_NAC_RAD'
|
'CASSINI_ISS_WAC_RAD'
|
'CASSINI_CIRS_FPB'
| |
| 'CASSINI_CIRS_FP1'
| |
| 'CASSINI_CIRS_FP3'
| |
| 'CASSINI_CIRS_FP4'
|
'CASSINI_CIRS_RAD'
|
'CASSINI_UVIS_FUV'
|
'CASSINI_UVIS_EUV'
|
'CASSINI_UVIS_SOLAR'
|
'CASSINI_UVIS_HSP'
|
'CASSINI_UVIS_HDAC'
|
'CASSINI_VIMS_V'
|
'CASSINI_VIMS_IR'
|
'CASSINI_VIMS_IR_SOL'
|
'CASSINI_VIMS_RAD'
|
'CASSINI_CAPS_BASE'
| |
| |<--- ck
| |
| 'CASSINI_CAPS_ART'
| |
| |<--- ck
| |
o------'CASSINI_CAPS'
| ^
| |
| + ck
|
'CASSINI_CDA_BASE'
| |
| |<--- ck
| |
| 'CASSINI_CDA_ART'
| |
| |<--- ck
| |
o------'CASSINI_CDA'
| ^
| |
| + ck
|
'CASSINI_INMS'
|
'CASSINI_MAG_PLUS'
|
'CASSINI_MAG_MINUS'
|
'CASSINI_MIMI_CHEMS'
|
'CASSINI_MIMI_INCA'
|
'CASSINI_MIMI_LEMMS_BASE'
| |
| |<--- ck
| |
| 'CASSINI_MIMI_LEMMS_ART'
| |
| |<--- ck
| |
o------'CASSINI_MIMI_LEMMS1'
| ^ |
| | |
| + ck |
| |
o------'CASSINI_MIMI_LEMMS2'
| ^
| |
| + ck
|
'CASSINI_RADAR_1'
|
'CASSINI_RADAR_2'
|
'CASSINI_RADAR_3'
|
'CASSINI_RADAR_4'
|
'CASSINI_RADAR_5'
|
'CASSINI_RPWS'
|
'CASSINI_RPWS_EXPLUS'
|
'CASSINI_RPWS_EXMINUS'
|
'CASSINI_RPWS_EZPLUS'
|
'CASSINI_RPWS_LP'
Spacecraft Frame
----------------------------------------------------------
From [8]: (Note: The figures referenced below can not be reproduced here.
There is a diagram below that basically illustrates what is contained
there.)
``The Stellar reference Unit (SRU) detector is a CCD. Its coordinate system
is defined according to the geometry of the detector. Figure 2.1.2a depicts
the SRU orientation and coordinates relative to the S/C coordinates. From
the ACS point of view, the S/C coordinate system is defined with respect to
the SRU coordinate frame, such that :
+X = +b (SRU boresight)
+Y = +v
+Z = -h
Therefore, by definition, there are no misalignments between the SRU and
the S/C coordinate frames.
The SRU coordinate system is defined by the pixel and line shift directions
defined in Figure 2.1.2b. These directions are represented by unit vectors
h and v respectively. Both h and v pass through the origin which is located
at the exact center of the 1024 x 1024 array. As indicated in Figure
2.1.2b, the SRU boresight b passes through this point, is normal to both h
and v, and points outward through the optics towards the scene being
viewed.''
Stellar Reference Unit Frame:
Cassini Spacecraft
/\
----------------------------------
\ /
\ / HGA
\ /
MAG Boom --------------------------
... =================| |
| h |
\ ^ /
| | |
| | |
Y <-------| v <---o |
sc | b, X |
| sc |
| |
| |
| |
| |
----------------------
/ \
/ \ Main Rocket Engine
----------
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where b and X point out of the screen or page.
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From [8]:
``The spacecraft basebody coordinate system is a body fixed coordinate
system. It is a structural coordinate system defined when the spacecraft is
assembled. The primary geometrical and mass properties are fixed to this
system. The (X,Y,Z) coordinate system is not observable in space.
Referring to Figure 2.1.1, the origin of the spacecraft coordinate system
lies at the center of the field joint between the bus and the upper
equipment module (UEM) upper shell structure assembly [7]. This location is
defined by bolt holes A, D, and H (as shown on the Configuration lay out
10129891, Figure 3). The Z-axis emanates from the origin and is
perpendicular to a plane generated by the mating surfaces of the bus at
bolt holes A, D, and H. The +Z-axis is on the propulsion module side of the
interface. The X-axis emanates from the origin and is parallel to the line
through the true centers of bolt holes A and H at the bus and the UEM upper
shell structure assembly interface. The -X-axis points towards the Huygens
probe. The Y-axis is mutually perpendicular to the X and Z axes, with the
+Y axis oriented along the magnetometer boom.''
Spacecraft bus attitude with respect to an inertial frame is provided by a
C kernel (see [1] for more information).
\begindata
FRAME_CASSINI_SC_COORD = -82000
FRAME_-82000_NAME = 'CASSINI_SC_COORD'
FRAME_-82000_CLASS = 3
FRAME_-82000_CLASS_ID = -82000
FRAME_-82000_CENTER = -82
CK_-82000_SCLK = -82
CK_-82000_SPK = -82
\begintext
The nominal definition of the Stellar Reference Unit-A frame is displayed
below. As described above and in [8], the boresight axis lies along the
spacecraft +X axis. The rotation matrix that takes vectors from the SRU-A
frame into the spacecraft frame is computed:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_SRU-A = -82001
FRAME_-82001_NAME = 'CASSINI_SRU-A'
FRAME_-82001_CLASS = 4
FRAME_-82001_CLASS_ID = -82001
FRAME_-82001_CENTER = -82
TKFRAME_-82001_SPEC = 'ANGLES'
TKFRAME_-82001_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82001_ANGLES = ( 0.0, -90.0, 0.0 )
TKFRAME_-82001_AXES = ( 3, 2, 1 )
TKFRAME_-82001_UNITS = 'DEGREES'
\begintext
The nominal definition of the Stellar Reference Unit-B frame is displayed
below. Nominally SRU-A and SRU-B are aligned, so the boresight axis lies
along the spacecraft +X axis. The rotation matrix that takes vectors from
the SRU-B frame into the spacecraft frame is computed:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_SRU-B = -82002
FRAME_-82002_NAME = 'CASSINI_SRU-B'
FRAME_-82002_CLASS = 4
FRAME_-82002_CLASS_ID = -82002
FRAME_-82002_CENTER = -82
TKFRAME_-82002_SPEC = 'ANGLES'
TKFRAME_-82002_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82002_ANGLES = ( 0.0, -90.0, 0.0 )
TKFRAME_-82002_AXES = ( 3, 2, 1 )
TKFRAME_-82002_UNITS = 'DEGREES'
\begintext
The nominal definition of the Stellar Reference Unit-A Radiator frame is
displayed below. As described in [32], the rotation matrix that takes
vectors from the SRU-A_RAD frame into the spacecraft frame is computed:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 180.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_SRU-A_RAD = -82008
FRAME_-82008_NAME = 'CASSINI_SRU-A_RAD'
FRAME_-82008_CLASS = 4
FRAME_-82008_CLASS_ID = -82008
FRAME_-82008_CENTER = -82
TKFRAME_-82008_SPEC = 'ANGLES'
TKFRAME_-82008_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82008_ANGLES = ( 180.0, -90.0, 0.0 )
TKFRAME_-82008_AXES = ( 3, 1, 3 )
TKFRAME_-82008_UNITS = 'DEGREES'
\begintext
The nominal definition of the Stellar Reference Unit-B Radiator frame is
displayed below. As with the SRU-B frame, this is nominally the same frame
as SRU-A_RAD. The rotation matrix that takes vectors from the SRU-B_RAD
frame into the spacecraft frame is computed:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 180.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_SRU-B_RAD = -82009
FRAME_-82009_NAME = 'CASSINI_SRU-B_RAD'
FRAME_-82009_CLASS = 4
FRAME_-82009_CLASS_ID = -82009
FRAME_-82009_CENTER = -82
TKFRAME_-82009_SPEC = 'ANGLES'
TKFRAME_-82009_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82009_ANGLES = ( 180.0, -90.0, 0.0 )
TKFRAME_-82009_AXES = ( 3, 1, 3 )
TKFRAME_-82009_UNITS = 'DEGREES'
\begintext
Antenna Frame Definitions
----------------------------------------------------------
This section of the frames kernel defines the Cassini spacecraft antenna
frames. The ID codes associated with each of the frames are determined by
subtracting the three digit antenna code (101-103) from the DSN Cassini
spacecraft bus ID code (-82000).
Note the angles in the frame definitions are specified for the "from
antenna to (relative to) base frame" transformation.
High Gain Antenna (HGA)
The high gain antenna points nominally along the spacecraft -Z axis. As
such the rotation matrix required that takes vectors represented in the
high gain antenna frame into the spacecraft frame is constructed as
follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ +180.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_HGA = -82101
FRAME_-82101_NAME = 'CASSINI_HGA'
FRAME_-82101_CLASS = 4
FRAME_-82101_CLASS_ID = -82101
FRAME_-82101_CENTER = -82
TKFRAME_-82101_SPEC = 'ANGLES'
TKFRAME_-82101_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82101_ANGLES = ( 0.0, 180.0, 0.0 )
TKFRAME_-82101_AXES = ( 3, 2, 1 )
TKFRAME_-82101_UNITS = 'DEGREES'
TKFRAME_-82101_BORESIGHT = ( 0.0, 0.0, 1.0 )
\begintext
The XBAND, XBAND_TRUE, KABAND, KUBAND, and SBAND frames are all frames
associated with the orbiter's High Gain Antenna. These names were chosen
for reasons of consistency with AACS, PDT, and sequencing software.
High Gain Antenna X Band (XBAND)
The high gain antenna is capable of operating in several bands, each of
which may be calibrated and adjusted independently. The nominal frame
definition for the XBAND is displayed below:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 180.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
FRAME_CASSINI_XBAND = -82104
FRAME_-82104_NAME = 'CASSINI_XBAND'
FRAME_-82104_CLASS = 4
FRAME_-82104_CLASS_ID = -82104
FRAME_-82104_CENTER = -82
TKFRAME_-82104_SPEC = 'ANGLES'
TKFRAME_-82104_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82104_ANGLES = ( 0.0, 0.0, 180.0 )
TKFRAME_-82104_AXES = ( 3, 2, 1 )
TKFRAME_-82104_UNITS = 'DEGREES'
From [25], the XBAND boresight has been adjusted to the following vector in
spacecraft coordinates:
[ 0.0005000 ]
XBAND Boresight Vector = [ 0.0004000 ]
[ -0.9999998 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -128.659808 ] [ -179.963313 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
First Updated Frame Definition:
FRAME_CASSINI_XBAND = -82104
FRAME_-82104_NAME = 'CASSINI_XBAND'
FRAME_-82104_CLASS = 4
FRAME_-82104_CLASS_ID = -82104
FRAME_-82104_CENTER = -82
TKFRAME_-82104_SPEC = 'ANGLES'
TKFRAME_-82104_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82104_ANGLES = ( -128.659808, -179.963313, 0.0 )
TKFRAME_-82104_AXES = ( 3, 1, 3 )
TKFRAME_-82104_UNITS = 'DEGREES'
From [34], the XBAND boresight has been adjusted again to the following
vector in spacecraft coordinates:
[ 0.0005200 ]
XBAND Boresight Vector = [ 0.0005800 ]
[ -0.9999997 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -138.12213046232 ] [ -179.95536809121 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Second Updated Frame Definition:
FRAME_CASSINI_XBAND = -82104
FRAME_-82104_NAME = 'CASSINI_XBAND'
FRAME_-82104_CLASS = 4
FRAME_-82104_CLASS_ID = -82104
FRAME_-82104_CENTER = -82
TKFRAME_-82104_SPEC = 'ANGLES'
TKFRAME_-82104_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82104_ANGLES = ( -138.12213046232,
-179.95536809121,
0.0 )
TKFRAME_-82104_AXES = ( 3,
1,
3 )
TKFRAME_-82104_UNITS = 'DEGREES'
From [35], the XBAND boresight has been adjusted to the following vector in
spacecraft coordinates:
[ 0.0004839 ]
XBAND Boresight Vector = [ 0.0001745 ]
[ -0.9999999 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -109.82989689352 ] [ -179.97052693372 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Third Updated Frame Definition:
FRAME_CASSINI_XBAND = -82104
FRAME_-82104_NAME = 'CASSINI_XBAND'
FRAME_-82104_CLASS = 4
FRAME_-82104_CLASS_ID = -82104
FRAME_-82104_CENTER = -82
TKFRAME_-82104_SPEC = 'ANGLES'
TKFRAME_-82104_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82104_ANGLES = ( -109.82989689352,
-179.97052693372,
0.0 )
TKFRAME_-82104_AXES = ( 3,
1,
3 )
TKFRAME_-82104_UNITS = 'DEGREES'
______________________________________________________________
++++++++++++++++++++March 18, 2003++++++++++++++++++++++++++++
From [46], the XBAND boresight has been adjusted so that it is co-aligned
with the KABAND boresight. By defining the frame relative to
'CASSINI_KABAND', the following frame definition is valid:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_XBAND = -82104
FRAME_-82104_NAME = 'CASSINI_XBAND'
FRAME_-82104_CLASS = 4
FRAME_-82104_CLASS_ID = -82104
FRAME_-82104_CENTER = -82
TKFRAME_-82104_SPEC = 'ANGLES'
TKFRAME_-82104_RELATIVE = 'CASSINI_KABAND'
TKFRAME_-82104_ANGLES = ( 0.0,
0.0,
0.0 )
TKFRAME_-82104_AXES = ( 3,
1,
2 )
TKFRAME_-82104_UNITS = 'DEGREES'
\begintext
High Gain Antenna X Band True (XBAND_TRUE)
______________________________________________________________
++++++++++++++++++++March 18, 2003++++++++++++++++++++++++++++
In order to preserve the original boresight information for the XBAND
antenna, a new frame is defined containing that information. The change
history is documented above under the XBAND frame.
From [35], the XBAND boresight has been adjusted to the following vector in
spacecraft coordinates:
[ 0.0004839 ]
XBAND Boresight Vector = [ 0.0001745 ]
[ -0.9999999 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -109.82989689352 ] [ -179.97052693372 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_XBAND_TRUE = -82108
FRAME_-82108_NAME = 'CASSINI_XBAND_TRUE'
FRAME_-82108_CLASS = 4
FRAME_-82108_CLASS_ID = -82108
FRAME_-82108_CENTER = -82
TKFRAME_-82108_SPEC = 'ANGLES'
TKFRAME_-82108_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82108_ANGLES = ( -109.82989689352,
-179.97052693372,
0.0 )
TKFRAME_-82108_AXES = ( 3,
1,
3 )
TKFRAME_-82108_UNITS = 'DEGREES'
\begintext
High Gain Antenna KA Band (KABAND)
The high gain antenna is capable of operating in several bands, each of
which may be calibrated and adjusted independently. The nominal frame
definition for the KABAND is displayed below:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 180.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
FRAME_CASSINI_KABAND = -82105
FRAME_-82105_NAME = 'CASSINI_KABAND'
FRAME_-82105_CLASS = 4
FRAME_-82105_CLASS_ID = -82105
FRAME_-82105_CENTER = -82
TKFRAME_-82105_SPEC = 'ANGLES'
TKFRAME_-82105_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82105_ANGLES = ( 0.0, 0.0, 180.0 )
TKFRAME_-82105_AXES = ( 3, 2, 1 )
TKFRAME_-82105_UNITS = 'DEGREES'
From [25], the KABAND boresight has been adjusted to the following vector
in spacecraft coordinates:
[ 0.0005000 ]
KABAND Boresight Vector = [ 0.0004000 ]
[ -0.9999998 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -128.659808 ] [ -179.963313 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
First Updated Frame Definition:
FRAME_CASSINI_KABAND = -82105
FRAME_-82105_NAME = 'CASSINI_KABAND'
FRAME_-82105_CLASS = 4
FRAME_-82105_CLASS_ID = -82105
FRAME_-82105_CENTER = -82
TKFRAME_-82105_SPEC = 'ANGLES'
TKFRAME_-82105_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82105_ANGLES = ( -128.659808, -179.963313, 0.0 )
TKFRAME_-82105_AXES = ( 3, 1, 3 )
TKFRAME_-82105_UNITS = 'DEGREES'
From [34], the KABAND boresight has been adjusted again to the following
vector in spacecraft coordinates:
[ 0.0005300 ]
KABAND Boresight Vector = [ 0.0006600 ]
[ -0.9999996 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -141.23448009520 ] [ -179.95150122158 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Second Updated Frame Definition:
FRAME_CASSINI_KABAND = -82105
FRAME_-82105_NAME = 'CASSINI_KABAND'
FRAME_-82105_CLASS = 4
FRAME_-82105_CLASS_ID = -82105
FRAME_-82105_CENTER = -82
TKFRAME_-82105_SPEC = 'ANGLES'
TKFRAME_-82105_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82105_ANGLES = ( -141.23448009520,
-179.95150122158,
0.0 )
TKFRAME_-82105_AXES = ( 3,
1,
3 )
TKFRAME_-82105_UNITS = 'DEGREES'
From [35], the KABAND boresight has been adjusted to the following vector
in spacecraft coordinates:
[ 0.0004839 ]
KABAND Boresight Vector = [ 0.0001745 ]
[ -0.9999999 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -109.82989689352 ] [ -179.97052693372 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
FRAME_CASSINI_KABAND = -82105
FRAME_-82105_NAME = 'CASSINI_KABAND'
FRAME_-82105_CLASS = 4
FRAME_-82105_CLASS_ID = -82105
FRAME_-82105_CENTER = -82
TKFRAME_-82105_SPEC = 'ANGLES'
TKFRAME_-82105_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82105_ANGLES = ( -109.82989689352,
-179.97052693372,
0.0 )
TKFRAME_-82105_AXES = ( 3,
1,
3 )
TKFRAME_-82105_UNITS = 'DEGREES'
From [38], the KABAND boresight has been adjusted to the following vector
in spacecraft coordinates:
[ 0.0005280 ]
KABAND Boresight Vector = [ 0.0003500 ]
[ -0.9999998 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -123.53955356526 ] [ -179.96370485104 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
FRAME_CASSINI_KABAND = -82105
FRAME_-82105_NAME = 'CASSINI_KABAND'
FRAME_-82105_CLASS = 4
FRAME_-82105_CLASS_ID = -82105
FRAME_-82105_CENTER = -82
TKFRAME_-82105_SPEC = 'ANGLES'
TKFRAME_-82105_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82105_ANGLES = ( -123.53955356526,
-179.96370485104,
0.0 )
TKFRAME_-82105_AXES = ( 3,
1,
3 )
TKFRAME_-82105_UNITS = 'DEGREES'
______________________________________________________________
++++++++++++++++++++November 20, 2003++++++++++++++++++++++++++++
From [48], the KABAND boresight has been adjusted to the following vector
in spacecraft coordinates:
[ 0.0004273 ]
KABAND Boresight Vector = [ 0.0008606 ]
[ -0.9999995 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -153.59495523828 ] [ -179.94494778906 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_KABAND = -82105
FRAME_-82105_NAME = 'CASSINI_KABAND'
FRAME_-82105_CLASS = 4
FRAME_-82105_CLASS_ID = -82105
FRAME_-82105_CENTER = -82
TKFRAME_-82105_SPEC = 'ANGLES'
TKFRAME_-82105_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82105_ANGLES = ( -153.59495523828,
-179.94494778906,
0.0 )
TKFRAME_-82105_AXES = ( 3,
1,
3 )
TKFRAME_-82105_UNITS = 'DEGREES'
\begintext
High Gain Antenna KU Band (KUBAND)
The high gain antenna is capable of operating in several bands, each of
which may be calibrated and adjusted independently. The nominal frame
definition for the KUBAND is displayed below:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 180.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_KUBAND = -82106
FRAME_-82106_NAME = 'CASSINI_KUBAND'
FRAME_-82106_CLASS = 4
FRAME_-82106_CLASS_ID = -82106
FRAME_-82106_CENTER = -82
TKFRAME_-82106_SPEC = 'ANGLES'
TKFRAME_-82106_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82106_ANGLES = ( 0.0, 0.0, 180.0 )
TKFRAME_-82106_AXES = ( 3, 2, 1 )
TKFRAME_-82106_UNITS = 'DEGREES'
\begintext
High Gain Antenna S Band (SBAND)
The high gain antenna is capable of operating in several bands, each of
which may be calibrated and adjusted independently. The nominal frame
definition for the SBAND is displayed below:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 180.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_SBAND = -82107
FRAME_-82107_NAME = 'CASSINI_SBAND'
FRAME_-82107_CLASS = 4
FRAME_-82107_CLASS_ID = -82107
FRAME_-82107_CENTER = -82
TKFRAME_-82107_SPEC = 'ANGLES'
TKFRAME_-82107_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82107_ANGLES = ( 0.0, 0.0, 180.0 )
TKFRAME_-82107_AXES = ( 3, 2, 1 )
TKFRAME_-82107_UNITS = 'DEGREES'
\begintext
Low Gain Antenna One (LGA1)
The first low gain antenna points nominally along the spacecraft -Z axis.
As such the rotation matrix required that takes vectors represented in the
first low gain antenna frame into the spacecraft frame is constructed as
follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ +180.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_LGA1 = -82102
FRAME_-82102_NAME = 'CASSINI_LGA1'
FRAME_-82102_CLASS = 4
FRAME_-82102_CLASS_ID = -82102
FRAME_-82102_CENTER = -82
TKFRAME_-82102_SPEC = 'ANGLES'
TKFRAME_-82102_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82102_ANGLES = ( 0.0, 180.0, 0.0 )
TKFRAME_-82102_AXES = ( 3, 2, 1 )
TKFRAME_-82102_UNITS = 'DEGREES'
TKFRAME_-82102_BORESIGHT = ( 0.0, 0.0, 1.0 )
\begintext
Low Gain Antenna Two (LGA2)
The second low gain antenna points nominally along the spacecraft -X axis.
As such the rotation matrix required that takes vectors represented in the
second low gain antenna frame into the spacecraft frame is constructed as
follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_LGA2 = -82103
FRAME_-82103_NAME = 'CASSINI_LGA2'
FRAME_-82103_CLASS = 4
FRAME_-82103_CLASS_ID = -82103
FRAME_-82103_CENTER = -82
TKFRAME_-82103_SPEC = 'ANGLES'
TKFRAME_-82103_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82103_ANGLES = ( 0.0, 90.0, 0.0 )
TKFRAME_-82103_AXES = ( 3, 2, 1 )
TKFRAME_-82103_UNITS = 'DEGREES'
TKFRAME_-82103_BORESIGHT = ( 0.0, 0.0, 1.0 )
\begintext
ISS Frames
----------------------------------------------------------
The Narrow Angle Camera (NAC) and Wide Angle Camera (WAC) are mounted on
the remote sensing pallet on the +X side of the Cassini spacecraft, and
nominally directed along the -Y axis of the AACS body frame.
Note the angles in the frame definitions are specified for the "from
instrument to (relative to) base frame" transformation.
Imaging Science Subsystem Narrow Angle Camera (ISS_NAC)
The ISS NAC points nominally along the spacecraft -Y axis. The following
frame definition encapsulates this nominal frame.
From [8]:
``The Narrow Angle Camera (NAC) detector is a CCD. Its coordinate system is
defined according to the geometry of the detector. The narrow angle
coordinate system is defined in the same manner as the SRU coordinate
systems defined above and the four central pixels of center of the full CCD
are selected for the definition of the origin of the coordinate system.
The Narrow Angle Camera is the primary instrument on the Remote Sensing
Pallet (RSP). AACS is responsible for providing pointing knowledge of the
boresight vector of this instrument. All other RSP instruments use the
pointing provided to the NAC as their reference for determining their
pointing.''
Nominal Frame Definition:
FRAME_CASSINI_ISS_NAC = -82360
FRAME_-82360_NAME = 'CASSINI_ISS_NAC'
FRAME_-82360_CLASS = 4
FRAME_-82360_CLASS_ID = -82360
FRAME_-82360_CENTER = -82
TKFRAME_-82360_SPEC = 'ANGLES'
TKFRAME_-82360_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82360_ANGLES = ( -90.0, 0.0, 90.0 )
TKFRAME_-82360_AXES = ( 1, 2, 3 )
TKFRAME_-82360_UNITS = 'DEGREES'
[6] describes the inflight calibration of the ISS that was the result of
the CICLOPS (Cassini Imaging Central Laboratory for Operations) analysis of
8 NAC images that were taken during ICO (Instrument Checkout). The rotation
matrix that takes vectors represented in the ISS_NAC frame into the
spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -90.024236 ] [ -0.047029483 ] [ 89.892082 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The angles were taken directly from [6].
FRAME_CASSINI_ISS_NAC = -82360
FRAME_-82360_NAME = 'CASSINI_ISS_NAC'
FRAME_-82360_CLASS = 4
FRAME_-82360_CLASS_ID = -82360
FRAME_-82360_CENTER = -82
TKFRAME_-82360_SPEC = 'ANGLES'
TKFRAME_-82360_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82360_ANGLES = ( -90.024236, -0.047029483, 89.892082 )
TKFRAME_-82360_AXES = ( 1, 2, 3 )
TKFRAME_-82360_UNITS = 'DEGREES'
From [10]:
``The NAC boresight is not precisely aligned with the S/C -Y body vector.
Its alignment was determined during ICO-1 ISS observations of Spica, when
the spacecraft was using SRU-B for orientation determination. The alignment
parameters cited under Change Requested take into account the offset, as
determined by AACS, between SRU-A and SRU-B.''
[10] also describes a series of frame transformations that convert the
CASSINI_ISS_NAC frame into the CASSINI_SC_COORD frame, accounting for the
offset between SRU-A and SRU-B. This results in following frame definition:
The rotation matrix that takes vectors represented in the ISS_NAC frame
into the spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -89.99231636 ] [ -0.03586589 ] [ 89.93339682 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
FRAME_CASSINI_ISS_NAC = -82360
FRAME_-82360_NAME = 'CASSINI_ISS_NAC'
FRAME_-82360_CLASS = 4
FRAME_-82360_CLASS_ID = -82360
FRAME_-82360_CENTER = -82
TKFRAME_-82360_SPEC = 'ANGLES'
TKFRAME_-82360_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82360_ANGLES = (-89.99231636, -0.03586589, 89.93339682)
TKFRAME_-82360_AXES = ( 1, 2, 3 )
TKFRAME_-82360_UNITS = 'DEGREES'
From [16]:
``The following results were obtained by using 3 long exposure Fomalhaut
NAC frames, each with 6 stars and using a 3 parameter fit (shift in line,
shift in sample and rotation about optic axis).''
AACS NAC boresight
X 0.0005760 +/- 0.0000018
Y -0.99999982 +/- 0.00000001
Z -0.0001710 +/- 0.0000016
The results of the Fomalhaut image calibrations produced the following
update to the ISS_NAC frame defintion:
The rotation matrix that takes vectors represented in the ISS_NAC frame
into the spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -90.009796 ] [ -0.03300 ] [ 89.9148 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_ISS_NAC = -82360
FRAME_-82360_NAME = 'CASSINI_ISS_NAC'
FRAME_-82360_CLASS = 4
FRAME_-82360_CLASS_ID = -82360
FRAME_-82360_CENTER = -82
TKFRAME_-82360_SPEC = 'ANGLES'
TKFRAME_-82360_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82360_ANGLES = (-90.009796, -0.03300, 89.9148 )
TKFRAME_-82360_AXES = ( 1, 2, 3 )
TKFRAME_-82360_UNITS = 'DEGREES'
\begintext
Imaging Science Subsystem Wide Angle Camera (ISS_WAC)
The ISS WAC points nominally along the spacecraft -Y axis. The following
frame definition encapsulates this nominal frame.
Nominal Frame Definition:
FRAME_CASSINI_ISS_WAC = -82361
FRAME_-82361_NAME = 'CASSINI_ISS_WAC'
FRAME_-82361_CLASS = 4
FRAME_-82361_CLASS_ID = -82361
FRAME_-82361_CENTER = -82
TKFRAME_-82361_SPEC = 'ANGLES'
TKFRAME_-82361_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82361_ANGLES = ( -90.0, 0.0, 90.0 )
TKFRAME_-82361_AXES = ( 1, 2, 3 )
TKFRAME_-82361_UNITS = 'DEGREES'
[6] describes the inflight calibration of ISS that was the result of the
CICLOPS (Cassini Imaging Central Laboratory for Operations) analysis of 36
WAC images taken during ICO (Instrument Checkout). At this time the images
taken were only sufficient to develop the location of the WAC's optical
axis. There are three determinations of this axes location in the
spacecraft frame. In [7] V.Haemmerle suggests that the 2-parameter fit
average coupled with nominal twist would be the safest assumption to
determine the frame transformation from ISS_WAC to the AACS body frame. The
rotation matrix that takes ISS_WAC vectors into the spacecraft frame would
be constructed as follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ +89.9116120 ] [ -90.00059931 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
These angles were computed using the assumption that the WAC optical axis
lies along the vector:
[ 0.00154266 ]
WAC Optical Axis Vector = [ -0.99999881 ]
[ -0.00001046 ]
in AACS body coordinates. Further we assume nominal twist, hence the first
rotation about Z is 0.0 degrees.
FRAME_CASSINI_ISS_WAC = -82361
FRAME_-82361_NAME = 'CASSINI_ISS_WAC'
FRAME_-82361_CLASS = 4
FRAME_-82361_CLASS_ID = -82361
FRAME_-82361_CENTER = -82
TKFRAME_-82361_SPEC = 'ANGLES'
TKFRAME_-82361_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82361_ANGLES = ( 89.9116120, -90.00059931, 0.0 )
TKFRAME_-82361_AXES = ( 3, 2, 3 )
TKFRAME_-82361_UNITS = 'DEGREES'
From [11]:
``The WAC boresight is not precisely aligned with the S/C -Y body vector.
Its alignment was determined during ICO-1 ISS observations of Spica, when
the spacecraft was using SRU-B for orientation determination. The alignment
parameters cited under Change Request take into account the offset, as
determined by AACS, between SRU-A and SRU-B.''
Taking the boresight from the ECR ([11]):
[ 0.0013481161 ]
WAC Optical Axis Vector = [ -0.99999894 ]
[ 0.00054612156 ]
and assuming no twist, we derive the following angles:
[ ] [ ] [ ] [ ]
[ ROT ] = [ +89.9227586 ] [ -89.96870954 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
These angles were computed using the assumption that the WAC optical axis
lies along the vector listed above. Further we assume nominal twist, hence
the first rotation about Z is 0.0 degrees.
FRAME_CASSINI_ISS_WAC = -82361
FRAME_-82361_NAME = 'CASSINI_ISS_WAC'
FRAME_-82361_CLASS = 4
FRAME_-82361_CLASS_ID = -82361
FRAME_-82361_CENTER = -82
TKFRAME_-82361_SPEC = 'ANGLES'
TKFRAME_-82361_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82361_ANGLES = ( 89.9227586, -89.96870954, 0.0 )
TKFRAME_-82361_AXES = ( 3, 2, 3 )
TKFRAME_-82361_UNITS = 'DEGREES'
From [16]:
``The following results were obtained by using 3 long exposure Fomalhaut
WAC frames, each using 12 stars near the center of frame and using a 3
parameter fit (shift in line, shift in sample and rotation about optic
axis).''
AACS WAC boresight
X 0.00121834 +/- 0.00000078
Y -0.99999923 +/- 0.00000001
Z 0.00025445 +/- 0.00000094
The results of the Fomalhaut image calibrations produced the following
update to the ISS_WAC frame defintion:
The rotation matrix that takes vectors represented in the ISS_NAC frame
into the spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -89.985421 ] [ -0.069806 ] [ 89.9736 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_ISS_WAC = -82361
FRAME_-82361_NAME = 'CASSINI_ISS_WAC'
FRAME_-82361_CLASS = 4
FRAME_-82361_CLASS_ID = -82361
FRAME_-82361_CENTER = -82
TKFRAME_-82361_SPEC = 'ANGLES'
TKFRAME_-82361_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82361_ANGLES = ( -89.985421, -0.069806, 89.9736 )
TKFRAME_-82361_AXES = ( 1, 2, 3 )
TKFRAME_-82361_UNITS = 'DEGREES'
\begintext
ISS Radiators (ISS_NAC_RAD and ISS_WAC_RAD)
The ISS radiators are nominally oriented with their +Z axes directed down
the spacecraft +X axis.
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
As [17] indicates, both the ISS_NAC_RAD and ISS_WAC_RAD boresights are
nominally aligned with the +X axis in the spacecraft frame. By the
methodology outlined above, this produces the following frame definitions:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -90.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_ISS_NAC_RAD = -82368
FRAME_-82368_NAME = 'CASSINI_ISS_NAC_RAD'
FRAME_-82368_CLASS = 4
FRAME_-82368_CLASS_ID = -82368
FRAME_-82368_CENTER = -82
TKFRAME_-82368_SPEC = 'ANGLES'
TKFRAME_-82368_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82368_ANGLES = ( -90.0, -90.0, 0.0 )
TKFRAME_-82368_AXES = ( 3, 1, 3 )
TKFRAME_-82368_UNITS = 'DEGREES'
\begintext
Since the boresights are the same, both frame definitions are also the
same, thus we have:
Nominal Frame Definition:
\begindata
FRAME_CASSINI_ISS_WAC_RAD = -82369
FRAME_-82369_NAME = 'CASSINI_ISS_WAC_RAD'
FRAME_-82369_CLASS = 4
FRAME_-82369_CLASS_ID = -82369
FRAME_-82369_CENTER = -82
TKFRAME_-82369_SPEC = 'ANGLES'
TKFRAME_-82369_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82369_ANGLES = ( -90.0, -90.0, 0.0 )
TKFRAME_-82369_AXES = ( 3, 1, 3 )
TKFRAME_-82369_UNITS = 'DEGREES'
\begintext
CIRS Frames
----------------------------------------------------------
The Composite Infrared Spectrometer (CIRS) is mounted on the remote sensing
pallet on the +X side of the Cassini spacecraft, and nominally directed
along the -Y axis of the AACS body frame.
Note the angles in the frame definitions are specified for the "from
instrument to (relative to) base frame" transformation.
Composite Infrared Spectrometer Focal Plane Boresight (CIRS_FPB)
The CIRS FPB points nominally along the spacecraft -Y axis. The rotation
matrix that takes vectors represented in the CIRS_FPB frame into the
spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [-90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The following frame definition encapsulates this nominal frame:
Nominal Frame Definition
FRAME_CASSINI_CIRS_FPB = -82893
FRAME_-82893_NAME = 'CASSINI_CIRS_FPB'
FRAME_-82893_CLASS = 4
FRAME_-82893_CLASS_ID = -82893
FRAME_-82893_CENTER = -82
TKFRAME_-82893_SPEC = 'ANGLES'
TKFRAME_-82893_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82893_ANGLES = ( 0.0, -90.0, 0.0 )
TKFRAME_-82893_AXES = ( 3, 1, 2 )
TKFRAME_-82893_UNITS = 'DEGREES'
ECR 100515 [39] included mounting alignment updates for all CIRS focal
planes. The optical boresight has moved from it's nominal configuration of
the -Y axis in the spacecraft frame 1.7 milliradians towards +X and -0.04
milliradians towards -Z. The rotation matrix that takes vectors represented
in the CIRS_FPB frame into the spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ -90.002291831180 ] [ -0.09740282517 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_CIRS_FPB = -82893
FRAME_-82893_NAME = 'CASSINI_CIRS_FPB'
FRAME_-82893_CLASS = 4
FRAME_-82893_CLASS_ID = -82893
FRAME_-82893_CENTER = -82
TKFRAME_-82893_SPEC = 'ANGLES'
TKFRAME_-82893_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82893_ANGLES = (
0.0
-90.0022918311805233
-0.097402825172240,
)
TKFRAME_-82893_AXES = ( 3, 1, 2 )
TKFRAME_-82893_UNITS = 'DEGREES'
\begintext
Composite Infrared Spectrometer Focal Plane #1 (CIRS_FP1)
The CIRS FP1 points nominally along the spacecraft -Y axis. The following
frame definition encapsulates this nominal frame.
Nominal Frame Definition:
FRAME_CASSINI_CIRS_FP1 = -82890
FRAME_-82890_NAME = 'CASSINI_CIRS_FP1'
FRAME_-82890_CLASS = 4
FRAME_-82890_CLASS_ID = -82890
FRAME_-82890_CENTER = -82
TKFRAME_-82890_SPEC = 'ANGLES'
TKFRAME_-82890_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82890_ANGLES = ( -90.0, 0.0, 90.0 )
TKFRAME_-82890_AXES = ( 1, 2, 3 )
TKFRAME_-82890_UNITS = 'DEGREES'
[9] and [10] describe the most up to date values the orientation of the
CIRS focal planes. The rotation matrix that takes vectors represented in
the CIRS_FP1 frame into the CIRS_FPB frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 0.23319382 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The angles were computed from [10].
FRAME_CASSINI_CIRS_FP1 = -82890
FRAME_-82890_NAME = 'CASSINI_CIRS_FP1'
FRAME_-82890_CLASS = 4
FRAME_-82890_CLASS_ID = -82890
FRAME_-82890_CENTER = -82
TKFRAME_-82890_SPEC = 'ANGLES'
TKFRAME_-82890_RELATIVE = 'CASSINI_CIRS_FPB'
TKFRAME_-82890_ANGLES = ( 0.0, 0.0, -0.23319382 )
TKFRAME_-82890_AXES = ( 3, 1, 2 )
TKFRAME_-82890_UNITS = 'DEGREES'
[39] introduces new offsets for the FP1 from the optical boresight (FPB).
They are: 3.98 milliradians towards +X in the spacecraft frame and 0.07
milliradians towards +Z in the spacecraft frame. These offsets result in
the following rotation matrix:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0040107045659 ] [ -0.22803720246 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_CIRS_FP1 = -82890
FRAME_-82890_NAME = 'CASSINI_CIRS_FP1'
FRAME_-82890_CLASS = 4
FRAME_-82890_CLASS_ID = -82890
FRAME_-82890_CENTER = -82
TKFRAME_-82890_SPEC = 'ANGLES'
TKFRAME_-82890_RELATIVE = 'CASSINI_CIRS_FPB'
TKFRAME_-82890_ANGLES = (
0.0,
4.0107045659158E-03,
-2.2803720246207E-01
)
TKFRAME_-82890_AXES = ( 3, 1, 2 )
TKFRAME_-82890_UNITS = 'DEGREES'
\begintext
Composite Infrared Spectrometer Focal Plane #3 (CIRS_FP3)
The CIRS FP3 points nominally along the spacecraft -Y axis. The following
frame definition encapsulates this nominal frame.
Nominal Frame Definition:
FRAME_CASSINI_CIRS_FP3 = -82891
FRAME_-82891_NAME = 'CASSINI_CIRS_FP3'
FRAME_-82891_CLASS = 4
FRAME_-82891_CLASS_ID = -82891
FRAME_-82891_CENTER = -82
TKFRAME_-82891_SPEC = 'ANGLES'
TKFRAME_-82891_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82891_ANGLES = ( -90.0, 0.0, 90.0 )
TKFRAME_-82891_AXES = ( 1, 2, 3 )
TKFRAME_-82891_UNITS = 'DEGREES'
[9] and [10] describe the most up to date values the orientation of the
CIRS focal planes. The rotation matrix that takes vectors represented in
the CIRS_FP3 frame into the CIRS_FPB frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 0.002549662 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The angles were computed from [10] with updates from [15].
FRAME_CASSINI_CIRS_FP3 = -82891
FRAME_-82891_NAME = 'CASSINI_CIRS_FP3'
FRAME_-82891_CLASS = 4
FRAME_-82891_CLASS_ID = -82891
FRAME_-82891_CENTER = -82
TKFRAME_-82891_SPEC = 'ANGLES'
TKFRAME_-82891_RELATIVE = 'CASSINI_CIRS_FPB'
TKFRAME_-82891_ANGLES = ( 0.0, 0.0, 0.02549662 )
TKFRAME_-82891_AXES = ( 3, 1, 2 )
TKFRAME_-82891_UNITS = 'DEGREES'
[39] includes an update to the offset of CASSINI_CIRS_FP3 from
CASSINI_CIRS_FPB. Instead of 0.445 milliradians, the new value is 0.47
milliradians of separation between the optical boresight and focal plane
3's boresight. The rotation matrix that takes vectors represented in the
CIRS_FP3 frame into the CIRS_FPB frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 0.002692902 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_CIRS_FP3 = -82891
FRAME_-82891_NAME = 'CASSINI_CIRS_FP3'
FRAME_-82891_CLASS = 4
FRAME_-82891_CLASS_ID = -82891
FRAME_-82891_CENTER = -82
TKFRAME_-82891_SPEC = 'ANGLES'
TKFRAME_-82891_RELATIVE = 'CASSINI_CIRS_FPB'
TKFRAME_-82891_ANGLES = ( 0.0, 0.0, 2.6929016371149E-02 )
TKFRAME_-82891_AXES = ( 3, 1, 2 )
TKFRAME_-82891_UNITS = 'DEGREES'
\begintext
Composite Infrared Spectrometer Focal Plane #4 (CIRS_FP4)
The CIRS FP4 points nominally along the spacecraft -Y axis. The following
frame definition encapsulates this nominal frame.
Nominal Frame Definition:
FRAME_CASSINI_CIRS_FP4 = -82892
FRAME_-82892_NAME = 'CASSINI_CIRS_FP4'
FRAME_-82892_CLASS = 4
FRAME_-82892_CLASS_ID = -82892
FRAME_-82892_CENTER = -82
TKFRAME_-82892_SPEC = 'ANGLES'
TKFRAME_-82892_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82892_ANGLES = ( -90.0, 0.0, 90.0 )
TKFRAME_-82892_AXES = ( 1, 2, 3 )
TKFRAME_-82892_UNITS = 'DEGREES'
[9] and [10] describe the most up to date values the orientation of the
CIRS focal planes. The rotation matrix that takes vectors represented in
the CIRS_FP4 frame into the CIRS_FPB frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -0.02549662 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The angles were taken directly from [10] with updates from [15].
FRAME_CASSINI_CIRS_FP4 = -82892
FRAME_-82892_NAME = 'CASSINI_CIRS_FP4'
FRAME_-82892_CLASS = 4
FRAME_-82892_CLASS_ID = -82892
FRAME_-82892_CENTER = -82
TKFRAME_-82892_SPEC = 'ANGLES'
TKFRAME_-82892_RELATIVE = 'CASSINI_CIRS_FPB'
TKFRAME_-82892_ANGLES = ( 0.0, 0.0, -0.02549662 )
TKFRAME_-82892_AXES = ( 3, 1, 2 )
TKFRAME_-82892_UNITS = 'DEGREES'
[39] includes an update to the offset of CASSINI_CIRS_FP4 from
CASSINI_CIRS_FPB. Instead of 0.445 milliradians, the new value is 0.47
milliradians of separation between the optical boresight and focal plane
4's boresight. The rotation matrix that takes vectors represented in the
CIRS_FP4 frame into the CIRS_FPB frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -0.002692902 ]
[ ] [ ] [ ] [ ]
Z X Y
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_CIRS_FP4 = -82892
FRAME_-82892_NAME = 'CASSINI_CIRS_FP4'
FRAME_-82892_CLASS = 4
FRAME_-82892_CLASS_ID = -82892
FRAME_-82892_CENTER = -82
TKFRAME_-82892_SPEC = 'ANGLES'
TKFRAME_-82892_RELATIVE = 'CASSINI_CIRS_FPB'
TKFRAME_-82892_ANGLES = ( 0.0, 0.0, -2.6929016371149E-02 )
TKFRAME_-82892_AXES = ( 3, 1, 2 )
TKFRAME_-82892_UNITS = 'DEGREES'
\begintext
CIRS Radiator (CIRS_RAD)
The CIRS radiator is nominally oriented with its +Z axis directed down the
spacecraft +X axis.
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
As [17] indicates, the CIRS_RAD boresight is nominally aligned with the +X
axis in the spacecraft frame. By the methodology outlined above, this
produces the following frame definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -90.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_CIRS_RAD = -82898
FRAME_-82898_NAME = 'CASSINI_CIRS_RAD'
FRAME_-82898_CLASS = 4
FRAME_-82898_CLASS_ID = -82898
FRAME_-82898_CENTER = -82
TKFRAME_-82898_SPEC = 'ANGLES'
TKFRAME_-82898_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82898_ANGLES = ( -90.0, -90.0, 0.0 )
TKFRAME_-82898_AXES = ( 3, 1, 3 )
TKFRAME_-82898_UNITS = 'DEGREES'
\begintext
UVIS Frames
----------------------------------------------------------
The Ultraviolet Imaging Spectrograph (UVIS) is mounted on the remote
sensing pallet on the +X side of the Cassini spacecraft, and nominally
directed along the -Y axis of the AACS body frame.
Note the angles in the frame definitions are specified for the "from
instrument to (relative to) base frame" transformation.
Ultraviolet Imaging Spectrograph Far Ultraviolet Spectrograph (UVIS_FUV)
An examination of [5] reveals that UVIS_FUV points nominally along the
spacecraft -Y axis. The rotation matrix that takes vectors represented in
the UVIS_FUV frame into the spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -90.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The following frame definition describes this nominal frame:
Nominal Frame Definition:
FRAME_CASSINI_UVIS_FUV = -82840
FRAME_-82840_NAME = 'CASSINI_UVIS_FUV'
FRAME_-82840_CLASS = 4
FRAME_-82840_CLASS_ID = -82840
FRAME_-82840_CENTER = -82
TKFRAME_-82840_SPEC = 'ANGLES'
TKFRAME_-82840_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82840_ANGLES = ( 0.0, 0.0, -90.0 )
TKFRAME_-82840_AXES = ( 3, 2, 1 )
TKFRAME_-82840_UNITS = 'DEGREES'
From [40], the UVIS_FUV boresight has been adjusted to the following vector
in spacecraft coordinates:
[ 0.0002 ]
UVIS_FUV Boresight Vector = [ -0.99999998 ]
[ 0.0001 ]
This leads to the following rotation matrix that takes vectors represented
in the UVIS_FUV frame into the spacecraft frame:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -89.9999 ] [ -0.011459 ] [ 0.005729 ]
[ ] [ ] [ ] [ ]
X Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_UVIS_FUV = -82840
FRAME_-82840_NAME = 'CASSINI_UVIS_FUV'
FRAME_-82840_CLASS = 4
FRAME_-82840_CLASS_ID = -82840
FRAME_-82840_CENTER = -82
TKFRAME_-82840_SPEC = 'ANGLES'
TKFRAME_-82840_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82840_ANGLES = (
-89.999999,
-0.01145916,
0.005729578
)
TKFRAME_-82840_AXES = ( 1, 2, 1 )
TKFRAME_-82840_UNITS = 'DEGREES'
\begintext
Ultraviolet Imaging Spectrograph Extreme Ultraviolet Spectrograph (UVIS_EUV)
An examination of [5] reveals that the UVIS_EUV points nominally along the
spacecraft -Y axis. The rotation matrix that takes vectors represented in
the UVIS_EUV frame into the spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -90.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The following frame definition describes this nominal frame:
Nominal Frame Definition:
FRAME_CASSINI_UVIS_EUV = -82842
FRAME_-82842_NAME = 'CASSINI_UVIS_EUV'
FRAME_-82842_CLASS = 4
FRAME_-82842_CLASS_ID = -82842
FRAME_-82842_CENTER = -82
TKFRAME_-82842_SPEC = 'ANGLES'
TKFRAME_-82842_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82842_ANGLES = ( 0.0, 0.0, -90.0 )
TKFRAME_-82842_AXES = ( 3, 2, 1 )
TKFRAME_-82842_UNITS = 'DEGREES'
From [40], the UVIS_EUV boresight has been adjusted to the following vector
in spacecraft coordinates:
[ 0.0012 ]
UVIS_EUV Boresight Vector = [ -0.99999843 ]
[ 0.0013 ]
This leads to the following rotation matrix that takes vectors represented
in the UVIS_EUV frame into the spacecraft frame:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -89.8984 ] [ -0.068755 ] [ -0.02704 ]
[ ] [ ] [ ] [ ]
X Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_UVIS_EUV = -82842
FRAME_-82842_NAME = 'CASSINI_UVIS_EUV'
FRAME_-82842_CLASS = 4
FRAME_-82842_CLASS_ID = -82842
FRAME_-82842_CENTER = -82
TKFRAME_-82842_SPEC = 'ANGLES'
TKFRAME_-82842_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82842_ANGLES = (
-89.8984716,
-0.068755,
-0.027044457
)
TKFRAME_-82842_AXES = ( 1, 2, 1 )
TKFRAME_-82842_UNITS = 'DEGREES'
\begintext
Ultraviolet Imaging Spectrograph Solar Occultation Port (UVIS_SOLAR)
[29] and [30] indicate that the UVIS solar occultation port points
nominally 20 degrees offset from the nominal UVIS boresights in the -Y
direction of the nominal instrument frames. The rotation matrix that takes
vectors represented in the CASSINI_UVIS_SOLAR frame into the
CASSINI_SC_COORD frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -110.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_UVIS_SOLAR = -82843
FRAME_-82843_NAME = 'CASSINI_UVIS_SOLAR'
FRAME_-82843_CLASS = 4
FRAME_-82843_CLASS_ID = -82843
FRAME_-82843_CENTER = -82
TKFRAME_-82843_SPEC = 'ANGLES'
TKFRAME_-82843_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82843_ANGLES = ( 0.0, 0.0, -110.0 )
TKFRAME_-82843_AXES = ( 3, 2, 1 )
TKFRAME_-82843_UNITS = 'DEGREES'
\begintext
Ultraviolet Imaging Spectrograph High Speed Photometer (UVIS_HSP)
An examination of [5] reveals that the UVIS_HSP points nominally along the
spacecraft -Y axis. The rotation matrix that takes vectors represented in
the UVIS_HSP frame into the spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -90.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The following frame definition describes this nominal frame:
Nominal Frame Definition:
FRAME_CASSINI_UVIS_HSP = -82844
FRAME_-82844_NAME = 'CASSINI_UVIS_HSP'
FRAME_-82844_CLASS = 4
FRAME_-82844_CLASS_ID = -82844
FRAME_-82844_CENTER = -82
TKFRAME_-82844_SPEC = 'ANGLES'
TKFRAME_-82844_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82844_ANGLES = ( 0.0, 0.0, -90.0 )
TKFRAME_-82844_AXES = ( 3, 2, 1 )
TKFRAME_-82844_UNITS = 'DEGREES'
From [40], the UVIS_HSP boresight has been adjusted to the following vector
in spacecraft coordinates:
[ 0.0012 ]
UVIS_HSP Boresight Vector = [ -0.99999856 ]
[ -0.0012 ]
This leads to the following rotation matrix that takes vectors represented
in the UVIS_HSP frame into the spacecraft frame:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -89.9028 ] [ -0.068755 ] [ -0.16599 ]
[ ] [ ] [ ] [ ]
X Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_UVIS_HSP = -82844
FRAME_-82844_NAME = 'CASSINI_UVIS_HSP'
FRAME_-82844_CLASS = 4
FRAME_-82844_CLASS_ID = -82844
FRAME_-82844_CENTER = -82
TKFRAME_-82844_SPEC = 'ANGLES'
TKFRAME_-82844_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82844_ANGLES = (
-89.9027658,
-0.068755,
-0.1659861
)
TKFRAME_-82844_AXES = ( 1, 2, 1 )
TKFRAME_-82844_UNITS = 'DEGREES'
\begintext
Ultraviolet Imaging Spectrograph Hydrogen - Deuterium Absorption Cell
(UVIS_HDAC)
An examination of [5] reveals that the UVIS_HDAC points nominally along the
spacecraft -Y axis. The rotation matrix that takes vectors represented in
the UVIS_HSP frame into the spacecraft frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -90.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
The following frame definition describes this nominal frame:
\begindata
FRAME_CASSINI_UVIS_HDAC = -82845
FRAME_-82845_NAME = 'CASSINI_UVIS_HDAC'
FRAME_-82845_CLASS = 4
FRAME_-82845_CLASS_ID = -82845
FRAME_-82845_CENTER = -82
TKFRAME_-82845_SPEC = 'ANGLES'
TKFRAME_-82845_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82845_ANGLES = ( 0.0, 0.0, -90.0 )
TKFRAME_-82845_AXES = ( 3, 2, 1 )
TKFRAME_-82845_UNITS = 'DEGREES'
\begintext
VIMS Frames
----------------------------------------------------------
The Visible and Infrared Mapping Spectrometer is mounted on the remote
sensing pallet on the +X side of the Cassini spacecraft, and nominally
directed along the -Y axis of the AACS body frame.
Note the angles in the frame definitions are specified for the ``from
instrument to (relative to) base frame'' transformation.
Visible and Infrared Mapping Spectrometer Visible (VIMS_V)
The VIMS_V detector points nominally along the spacecraft -Y axis. The
following frame definition encapsulates this nominal frame.
From [13]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -90.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_VIMS_V = -82370
FRAME_-82370_NAME = 'CASSINI_VIMS_V'
FRAME_-82370_CLASS = 4
FRAME_-82370_CLASS_ID = -82370
FRAME_-82370_CENTER = -82
TKFRAME_-82370_SPEC = 'ANGLES'
TKFRAME_-82370_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82370_ANGLES = ( 0.0, 0.0, -90.0 )
TKFRAME_-82370_AXES = ( 3, 2, 1 )
TKFRAME_-82370_UNITS = 'DEGREES'
\begintext
Visible and Infrared Mapping Spectrometer Infrared (VIMS_IR)
The VIMS_IR detector points nominally along the spacecraft -Y axis. The
following frame definition encapsulates this nominal frame.
From [13]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -90.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
FRAME_CASSINI_VIMS_IR = -82371
FRAME_-82371_NAME = 'CASSINI_VIMS_IR'
FRAME_-82371_CLASS = 4
FRAME_-82371_CLASS_ID = -82371
FRAME_-82371_CENTER = -82
TKFRAME_-82371_SPEC = 'ANGLES'
TKFRAME_-82371_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82371_ANGLES = ( 0.0, 0.0, -90.0 )
TKFRAME_-82371_AXES = ( 3, 2, 1 )
TKFRAME_-82371_UNITS = 'DEGREES'
From [41], the VIMS_IR boresight has been adjusted to the following vector
in spacecraft coordinates:
[ 0.0021251 ]
VIMS_IR Boresight Vector = [ -0.9999974 ]
[ -0.0008495 ]
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
By the methodology outlined above, this produces the following frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -360.121759 ] [ -90.0486727 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_VIMS_IR = -82371
FRAME_-82371_NAME = 'CASSINI_VIMS_IR'
FRAME_-82371_CLASS = 4
FRAME_-82371_CLASS_ID = -82371
FRAME_-82371_CENTER = -82
TKFRAME_-82371_SPEC = 'ANGLES'
TKFRAME_-82371_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82371_ANGLES = (
-360.12175939433,
-90.048672769633,
0.0
)
TKFRAME_-82371_AXES = ( 3, 1, 3 )
TKFRAME_-82371_UNITS = 'DEGREES'
\begintext
Visible and Infrared Mapping Spectrometer Infrared Solar Port (VIMS_IR_SOL)
[28] indicates that the VIMS IR channel solar port points nominally 20
degrees offset from the VIMS IR boresight in the -Y direction of the
VIMS_IR frame. The rotation matrix that takes vectors represented in the
VIMS_IR_SOL frame into the VIMS_IR frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ -20.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
FRAME_CASSINI_VIMS_IR_SOL = -82372
FRAME_-82372_NAME = 'CASSINI_VIMS_IR_SOL'
FRAME_-82372_CLASS = 4
FRAME_-82372_CLASS_ID = -82372
FRAME_-82372_CENTER = -82
TKFRAME_-82372_SPEC = 'ANGLES'
TKFRAME_-82372_RELATIVE = 'CASSINI_VIMS_IR'
TKFRAME_-82372_ANGLES = ( 0.0, 0.0, -20.0 )
TKFRAME_-82372_AXES = ( 3, 2, 1 )
TKFRAME_-82372_UNITS = 'DEGREES'
[42] requested that CASSINI_VIMS_IR_SOL be referenced directly to
CASSINI_SC_COORD. In addition, [42], [43], and [45] also carry updates to
the alignment of the solar port. The rotation matrix that takes vectors
represented in the VIMS_IR_SOL frame into the CASSINI_SC_COORD frame
follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0859436686699 ] [ 0.0 ] [ -110.630253571 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_VIMS_IR_SOL = -82372
FRAME_-82372_NAME = 'CASSINI_VIMS_IR_SOL'
FRAME_-82372_CLASS = 4
FRAME_-82372_CLASS_ID = -82372
FRAME_-82372_CENTER = -82
TKFRAME_-82372_SPEC = 'ANGLES'
TKFRAME_-82372_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82372_ANGLES = ( 0.085943668669984,
0.0,
-110.63025357166 )
TKFRAME_-82372_AXES = ( 3, 2, 1 )
TKFRAME_-82372_UNITS = 'DEGREES'
\begintext
Visible and Infrared Mapping Spectrometer Radiator (VIMS_RAD)
The VIMS radiator is nominally oriented with its +Z axis directed down the
spacecraft +X axis. This is not the case for the radiator plate itself,
which is mounted in the housing such that it is canted by 28.05 degrees. In
the spacecraft coordinate frame, the cant is towards the spacecraft -Y
axis.
This, however, is not the end of the story. Thermally, the radiator housing
and the radiator plate have interaction with respect to solar heating so
that the effective boresight for symmetric solar heating, regardless of
direction, is not offset by 28.05 degrees from the spacecraft +X axis.
Initially the +Z axis of the radiator frame was determined to be the +X
axis of the spacecraft frame. This results in the following:
Since only boresight information has been provided, the frame
transformation outlined below was constructed by computing the RA and DEC
of the boresight vector relative to the CASSINI_SC_COORD frame. These
angles are then utilized in the following fashion to construct the frame
definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -(RA+90) ] [ -(90-DEC) ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
This produces a frame whose Z-axis agrees with the specified boresight.
As [17] indicates, the VIMS_RAD boresight is nominally aligned with the +X
axis in the spacecraft frame. By the methodology outlined above, this
produces the following frame definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -90.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
FRAME_CASSINI_VIMS_RAD = -82378
FRAME_-82378_NAME = 'CASSINI_VIMS_RAD'
FRAME_-82378_CLASS = 4
FRAME_-82378_CLASS_ID = -82378
FRAME_-82378_CENTER = -82
TKFRAME_-82378_SPEC = 'ANGLES'
TKFRAME_-82378_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82378_ANGLES = ( -90.0, -90.0, 0.0 )
TKFRAME_-82378_AXES = ( 3, 1, 3 )
TKFRAME_-82378_UNITS = 'DEGREES'
From [36]:
A solar heating analysis and identification of a solar heating
``effective'' radiator boresight was performed for ECR 100325-B covering
Flight Rule FF37B2 [37]. The solar heating analysis identified that a VIMS
radiator boresight offset from the spacecraft +X axis in the direction of
the spacecraft -Y axis by 4.5 degrees would define a thermally
``effective'' boresight.
To implement this change, the rotation about the Z-axis needs to be
increased by 4.5 degrees as follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -85.5 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z X Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_VIMS_RAD = -82378
FRAME_-82378_NAME = 'CASSINI_VIMS_RAD'
FRAME_-82378_CLASS = 4
FRAME_-82378_CLASS_ID = -82378
FRAME_-82378_CENTER = -82
TKFRAME_-82378_SPEC = 'ANGLES'
TKFRAME_-82378_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82378_ANGLES = ( -85.5, -90.0, 0.0 )
TKFRAME_-82378_AXES = ( 3, 1, 3 )
TKFRAME_-82378_UNITS = 'DEGREES'
\begintext
CAPS Frames
----------------------------------------------------------
The Cassini Plasma Spectrometer is mounted on an actuator which is in turn
attached to the fields and particles pallet which is roughly located on the
-X side of the Cassini spacecraft.
The actuator allows the instrument to articulate, so to make proper use of
this frame requires a C-kernel (or set of C-kernels) with appropriate
coverage for the epochs of interest.
To connect the CASSINI_CAPS frame with the spacecraft coordinate frame
(CASSINI_SC_COORD) two possible branches exist depending on the set of
C-kernels loaded:
CASSINI_SC_COORD CASSINI_SC_COORD
---------------- ----------------
| |
|<--- fixed offset |
| |
V |
CASSINI_CAPS_BASE |
----------------- |
| |
|<--- c-kernel |<--- c-kernel
| |
V |
CASSINI_CAPS_ART |
---------------- |
| |
|<--- c-kernel |
| |
V V
CASSINI_CAPS CASSINI_CAPS
------------ ------------
The branch illustrated on the left of the figure above utilizes a series of
transformations to connect the spacecraft frame with the instrument frame.
The general strategy in this branch is the following:
-- Define a fixed offset frame that connects the spacecraft
frame to the base or 'zero-point' of the articulation of the
instrument.
-- Define a C-kernel based frame to perform the rotation about
the articulation axis.
-- Define a C-kernel based frame that performs the final
rotation necessary to produce the instrument frame.
This last frame in the absence of the right branch could be another fixed
offset frame. However, making it a C-kernel allows the branch on the right
to exist. This alternate route up the frame tree allows the construction
and use of C-kernels that tie the instrument frame directly back to the
spacecraft frame. This is often convenient for science data analysis.
Without further ado, the frame defintions:
Cassini Plasma Spectrometer Zero-Articulation Base Frame (CAPS_BASE)
The Z-axis of this frame is the articulation axis of CAPS. The X-axis is
constructed by taking the vector product of the CAPS articulation axis with
the boresight in the 'zero-angle' or base position. The Y-axis completes
the right handed frame. The articulation axis of CAPS is the Z-axis of
CASSINI_SC_COORD, and the boresight in its 'zero-angle' configuration is
the negative Y-axis of this spacecraft frame, so we end up with the
following:
The rotation matrix that takes vectors represented in the CAPS_BASE frame
into the spacecraft coordinate frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 0.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_CAPS_BASE = -82822
FRAME_-82822_NAME = 'CASSINI_CAPS_BASE'
FRAME_-82822_CLASS = 4
FRAME_-82822_CLASS_ID = -82822
FRAME_-82822_CENTER = -82
TKFRAME_-82822_SPEC = 'ANGLES'
TKFRAME_-82822_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82822_ANGLES = ( 0.0, 0.0, 0.0 )
TKFRAME_-82822_AXES = ( 3, 2, 1 )
TKFRAME_-82822_UNITS = 'DEGREES'
\begintext
Cassini Plasma Spectrometer Articulation Frame (CAPS_ART)
The Z-axis of this frame is the articulation axis of CAPS. The X-axis is
constructed by taking the vector product of the CAPS articulation axis with
the boresight at some articulated position. The Y-axis completes the right
handed frame.
This frame encapsulates the articulation characteristics of the CAPS
instrument. To make use of it requires a C-kernel with coverage at the
epochs of interest be loaded.
The rotation matrix that takes vectors from the CAPS_ART frame to the
CAPS_BASE frame follows:
[ ] [ ]
[ ROT ] = [ ANGLE ]
[ ] [ ]
Z
where [x] represents the rotation matrix of a given angle x about
i
axis i, and ANGLE is the articulation angle.
\begindata
FRAME_CASSINI_CAPS_ART = -82821
FRAME_-82821_NAME = 'CASSINI_CAPS_ART'
FRAME_-82821_CLASS = 3
FRAME_-82821_CLASS_ID = -82821
FRAME_-82821_CENTER = -82
CK_-82821_SCLK = -82
CK_-82821_SPK = -82
\begintext
Cassini Plasma Spectrometer Frame (CAPS)
The negative Y-axis of this frame is the instrument boresight. The Z-axis
is defined as the articulation axis of the detectors, and the X-axis
completes the right handed frame.
This frame requires one of two possible C-kernels:
-- One kernel connects this instrument frame (-82820) directly
to the spacecraft frame (-82000).
-- The other possible kernel connects this instrument frame
(-82820) to the articulation frame (-82821) defined above.
The kernel that makes this connection for all epochs after
launch is delivered with the kernel set. See the kernel
comments for details of frame construction.
One should take care in the simultaneous loading of C-kernels that utilize
different paths of the frame tree to connect CASSINI_CAPS to
CASSINI_SC_COORD. See [1] for details regarding C-kernel precedence.
\begindata
FRAME_CASSINI_CAPS = -82820
FRAME_-82820_NAME = 'CASSINI_CAPS'
FRAME_-82820_CLASS = 3
FRAME_-82820_CLASS_ID = -82820
FRAME_-82820_CENTER = -82
CK_-82820_SCLK = -82
CK_-82820_SPK = -82
\begintext
CDA Frames
----------------------------------------------------------
The Cosmic Dust Analyzer is mounted on the -X side of the Cassini
spacecraft. The entire assembly is capable of articulating from it's zero
angle position. The following describes the boresight in the spacecraft
frame as a function of the articulation angle a:
From [18]:
x = 1/8 ( -1 - SQRT(3) + (-1 + SQRT(3)) COS(a) - 2 SQRT(6) SIN(a) )
y = 1/8 ( 3 + SQRT(3) + (-3 + SQRT(3)) COS(a) - 2 SQRT(2) SIN(a) )
z = 1/4 ( -1 + SQRT(3) + ( 1 + SQRT(3)) COS(a) )
The actuator allows the instrument to articulate, so to make proper use of
this frame requires a C-kernel (or set of C-kernels) with appropriate
coverage for the epochs of interest.
To connect the CASSINI_CDA frame with the spacecraft coordinate frame
(CASSINI_SC_COORD) two possible branches exist depending on the set of
C-kernels loaded:
CASSINI_SC_COORD CASSINI_SC_COORD
---------------- ----------------
| |
|<--- fixed offset |
| |
V |
CASSINI_CDA_BASE |
---------------- |
| |
|<--- c-kernel |<--- c-kernel
| |
V |
CASSINI_CDA_ART |
--------------- |
| |
|<--- c-kernel |
| |
V V
CASSINI_CDA CASSINI_CDA
----------- -----------
The branch illustrated on the left of the figure above utilizes a series of
transformations to connect the spacecraft frame with the instrument frame.
The general strategy in this branch is the following:
-- Define a fixed offset frame that connects the spacecraft
frame to the base or 'zero-point' of the articulation of the
instrument.
-- Define a C-kernel based frame to perform the rotation about
the articulation axis.
-- Define a C-kernel based frame that performs the final
rotation necessary to produce the instrument frame.
This last frame in the absence of the right branch could be another fixed
offset frame. However, making it a C-kernel allows the branch on the right
to exist. This alternate route up the frame tree allows the construction
and use of C-kernels that tie the instrument frame directly back to the
spacecraft frame. This is often convenient for science data analysis.
Without further ado, the frame defintions:
Cosmic Dust Analyzer Zero-Articulation Base Frame (CDA_BASE)
The Z-axis of this frame is the articulation axis of CDA. The X-axis is
constructed by taking the vector product of the CDA articulation axis with
the boresight in the 'zero-angle' or base position. The Y-axis completes
the right handed frame.
An examination of the relationship connecting the boresight position in the
spacecraft frame with the articulation angle, yields the following:
The articulation axis of CDA in CASSINI_SC_COORD is:
(+4.8296291314453E-01, -8.3651630373781E-01, -2.5881904510252E-01)
The 'zero-angle' boresight in CASSINI_SC_COORD is:
(-2.5000000000000E-01, 4.3301270189222E-01, 8.6602540378444E-01)
The articulation axis points in the opposite direction of the cone swept
out by the boresight vectors. This was done to preserve the sense of the
positive angle in the definition provided in [18].
Computing the frame described above we end up with:
The rotation matrix that takes vectors represented in the CDA_BASE frame
into the spacecraft coordinate frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 150.0 ] [ 0.0 ] [ 105.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_CDA_BASE = -82792
FRAME_-82792_NAME = 'CASSINI_CDA_BASE'
FRAME_-82792_CLASS = 4
FRAME_-82792_CLASS_ID = -82792
FRAME_-82792_CENTER = -82
TKFRAME_-82792_SPEC = 'ANGLES'
TKFRAME_-82792_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82792_ANGLES = ( 150.0, 0.0, 105.0 )
TKFRAME_-82792_AXES = ( 3, 2, 1 )
TKFRAME_-82792_UNITS = 'DEGREES'
\begintext
Cosmic Dust Analyzer Articulation Frame (CDA_ART)
The Z-axis of this frame is the articulation axis of CDA. The X-axis is
constructed by taking the vector product of the CDA articulation axis with
the boresight at some articulated position. The Y-axis completes the right
handed frame.
This frame encapsulates the articulation characteristics of the CDA
instrument. To make use of it requires a C-kernel with coverage at the
epochs of interest be loaded.
The rotation matrix that takes vectors from the CDA_ART frame to the
CDA_BASE frame follows:
[ ] [ ]
[ ROT ] = [ ANGLE ]
[ ] [ ]
Z
where [x] represents the rotation matrix of a given angle x about
i
axis i, and ANGLE is the articulation angle.
\begindata
FRAME_CASSINI_CDA_ART = -82791
FRAME_-82791_NAME = 'CASSINI_CDA_ART'
FRAME_-82791_CLASS = 3
FRAME_-82791_CLASS_ID = -82791
FRAME_-82791_CENTER = -82
CK_-82791_SCLK = -82
CK_-82791_SPK = -82
\begintext
Cosmic Dust Analyzer Frame (CDA)
The Z-axis of this frame is the instrument boresight. The X-axis of is the
same as the X-axis of CASSINI_CDA_ART, and the Y-axis completes the right
handed frame.
This frame requires one of two possible C-kernels:
-- One kernel connects this instrument frame (-82790) directly
to the spacecraft frame (-82000).
-- The other possible kernel connects this instrument frame
(-82790) to the articulation frame (-82791) defined above.
The kernel that makes this connection for all epochs after
launch is delivered with the kernel set. See the kernel
comments for details of frame construction.
One should take care in the simultaneous loading of C-kernels that utilize
different paths of the frame tree to connect CASSINI_CDA to
CASSINI_SC_COORD. See [1] for details regarding C-kernel precedence.
\begindata
FRAME_CASSINI_CDA = -82790
FRAME_-82790_NAME = 'CASSINI_CDA'
FRAME_-82790_CLASS = 3
FRAME_-82790_CLASS_ID = -82790
FRAME_-82790_CENTER = -82
CK_-82790_SCLK = -82
CK_-82790_SPK = -82
\begintext
INMS Frames
----------------------------------------------------------
The Ion and Neutral Mass Spectrometer is mounted on the fields and
particles pallet roughly located on the -X side of the Cassini spacecraft.
The instrument boresight is nominally directed along the -X axis of the
AACS body frame.
Note the angles in the frame definitions are specified for the ``from
instrument to (relative to) base frame'' transformation.
From [19], we have the following nominal frame definition:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ +90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
x Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_INMS = -82740
FRAME_-82740_NAME = 'CASSINI_INMS'
FRAME_-82740_CLASS = 4
FRAME_-82740_CLASS_ID = -82740
FRAME_-82740_CENTER = -82
TKFRAME_-82740_SPEC = 'ANGLES'
TKFRAME_-82740_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82740_ANGLES = ( 0.0, +90.0, 0.0 )
TKFRAME_-82740_AXES = ( 1, 2, 3 )
TKFRAME_-82740_UNITS = 'DEGREES'
\begintext
MAG Frames
----------------------------------------------------------
The Magnetometer is mounted on the magentometer boom which protrudes from
the spacecraft body in the direction of the +Y axis of the AACS body frame.
[20] establishes the need for two separate frame definitions, one for the
Plus-X directed frame, the other for the Minux-X one.
Note the angles in the frame definitions are specified for the ``from
instrument to (relative to) base frame'' transformation.
Magnetometer Plus-X (MAG_PLUS)
The MAG_PLUS detector is pointed nominally in the direction of the
spacecraft +X axis. The following definition encapsulates this frame:
From [21]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_MAG_PLUS = -82350
FRAME_-82350_NAME = 'CASSINI_MAG_PLUS'
FRAME_-82350_CLASS = 4
FRAME_-82350_CLASS_ID = -82350
FRAME_-82350_CENTER = -82
TKFRAME_-82350_SPEC = 'ANGLES'
TKFRAME_-82350_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82350_ANGLES = ( 0.0, -90.0, 0.0 )
TKFRAME_-82350_AXES = ( 1, 2, 3 )
TKFRAME_-82350_UNITS = 'DEGREES'
\begintext
Magnetometer Minus-X (MAG_MINUS)
The MAG_MINUS detector is pointed nominally in the direction of the
spacecraft -X axis. The following definition encapsulates this frame:
From [21]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_MAG_MINUS = -82351
FRAME_-82351_NAME = 'CASSINI_MAG_MINUS'
FRAME_-82351_CLASS = 4
FRAME_-82351_CLASS_ID = -82351
FRAME_-82351_CENTER = -82
TKFRAME_-82351_SPEC = 'ANGLES'
TKFRAME_-82351_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82351_ANGLES = ( 0.0, 90.0, 0.0 )
TKFRAME_-82351_AXES = ( 1, 2, 3 )
TKFRAME_-82351_UNITS = 'DEGREES'
\begintext
MIMI Frames
----------------------------------------------------------
Most of the components of the Magnetospheric Imaging Instrument are mounted
on the fields and particles pallet roughly located on the -X side of the
Cassini spacecraft. The one exception is the Ion and Neutral Camera which
is mounted on the -Y side of the orbiter.
Note the angles in the frame definitions are specified for the ``from
instrument to (relative to) base frame'' transformation.
Magnetospheric Imaging Instrument Charge Energy Mass Spectrometer (MIMI_CHEMS)
The MIMI_CHEMS detector is nominally pointed along the -X axis of the
spacecraft frame. The following definition encapsulates this frame:
From [17]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 0.0 ] [ 90.0 ] [ 90.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_MIMI_CHEMS = -82760
FRAME_-82760_NAME = 'CASSINI_MIMI_CHEMS'
FRAME_-82760_CLASS = 4
FRAME_-82760_CLASS_ID = -82760
FRAME_-82760_CENTER = -82
TKFRAME_-82760_SPEC = 'ANGLES'
TKFRAME_-82760_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82760_ANGLES = ( 0.0, 90.0, 90.0 )
TKFRAME_-82760_AXES = ( 1, 2, 3 )
TKFRAME_-82760_UNITS = 'DEGREES'
\begintext
Magnetospheric Imaging Instrument Ion and Neutral Camera (MIMI_INCA)
The MIMI_INCA detector is nominally pointed along the -Y axis of the
spacecraft frame with a 9.5 degree offset in the direction of the +X axis
of the spacecraft. The following definition encapsulates this frame:
From [22]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -90.0 ] [ -9.5 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_MIMI_INCA = -82761
FRAME_-82761_NAME = 'CASSINI_MIMI_INCA'
FRAME_-82761_CLASS = 4
FRAME_-82761_CLASS_ID = -82761
FRAME_-82761_CENTER = -82
TKFRAME_-82761_SPEC = 'ANGLES'
TKFRAME_-82761_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82761_ANGLES = ( -90.0, -9.5, 0.0 )
TKFRAME_-82761_AXES = ( 1, 2, 3 )
TKFRAME_-82761_UNITS = 'DEGREES'
\begintext
Magnetospheric Imaging Instrument Low Energy Magnetospheric Measurements
(MIMI_LEMMS)
The actuator allows the detectors to articulate, so to make proper use of
this frame requires a C-kernel (or set of C-kernels) with appropriate
coverage for the epochs of interest.
To connect the CASSINI_MIMI_LEMMS1 and CASSINI_MIMI_LEMMS2 frames with the
spacecraft coordinate frame (CASSINI_SC_COORD) two possible branches exist
depending on the set of C-kernels loaded:
CASSINI_SC_COORD CASSINI_SC_COORD
---------------- ----------------
| | |
|<--- fixed offset | |
| | |
V | |
CASSINI_MIMI_LEMMS_BASE | |
----------------------- | |
| | |
|<--- c-kernel |<--- c-kernel |
| | |
V | |
CASSINI_MIMI_LEMMS_ART | |
---------------------- | |
| | | |
|<--- c-kernel | | c-kernel --->|
| | | |
V | V |
CASSINI_MIMI_LEMMS1 | CASSINI_MIMI_LEMMS1 |
------------------- | ------------------- |
| |
c-kernel --->| |
| |
V V
CASSINI_MIMI_LEMMS2 CASSINI_MIMI_LEMMS2
------------------- -------------------
The branches illustrated on the left of the figure above utilize a series
of transformations to connect the spacecraft frame with the detector
frames. The general strategy in these branches is the following:
-- Define a fixed offset frame that connects the spacecraft
frame to the base or 'zero-point' of the articulation of the
detectors.
-- Define a C-kernel based frame to perform the rotation about
the articulation axis.
-- Define a C-kernel based frame that performs the final
rotation necessary to produce either of the instrument frame.
These last frames (MIMI_LEMMS1 and MIMI_LEMMS2) in the absence of the right
branch could be another fixed offset frame. However, making them C-kernels
allows the branches on the right to exist. This alternate route up the
frame tree allows the construction and use of C-kernels that tie the
individual detector frames directly back to the spacecraft frame. This is
often convenient for science data analysis.
Without further ado, the frame defintions:
Magnetospheric Imaging Instrument Low Energy Magnetospheric Measurements
Zero-Articulation Base Frame (MIMI_LEMMS_BASE)
The Z-axis of this frame is the articulation axis of MIMI_LEMMS. The X-axis
is constructed by taking the vector product of the MIMI_LEMMS articulation
axis with the MIMI_LEMMS1 boresight in the 'zero-angle' or base position.
The Y-axis completes the right handed frame.
As [33] indicates, the articulation axis is the Y-axis in CASSINI_SC_COORD
and the 'zero-angle' boresight of MIMI_LEMMS1 is the -Z-axis in
CASSINI_SC_COORD. Combining this information with the frame definition laid
out above, we have:
The rotation matrix that takes vectors represented in the MIMI_LEMMS_BASE
frame into the spacecraft coordinate frame follows:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 180.0 ] [ 0.0 ] [ -90.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_MIMI_LEMMS_BASE = -82765
FRAME_-82765_NAME = 'CASSINI_MIMI_LEMMS_BASE'
FRAME_-82765_CLASS = 4
FRAME_-82765_CLASS_ID = -82765
FRAME_-82765_CENTER = -82
TKFRAME_-82765_SPEC = 'ANGLES'
TKFRAME_-82765_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82765_ANGLES = ( 180.0, 0.0, -90.0 )
TKFRAME_-82765_AXES = ( 3, 2, 1 )
TKFRAME_-82765_UNITS = 'DEGREES'
\begintext
Magnetospheric Imaging Instrument Low Energy Magnetospheric Measurements
Articulation Frame (MIMI_LEMMS_ART)
The Z-axis of this frame is the articulation axis of MIMI_LEMMS. The X-axis
is constructed by taking the vector product of the MIMI_LEMMS articulation
axis with the MIMI_LEMMS1 boresight at some articulated position. The
Y-axis completes the right handed frame.
This frame encapsulates the articulation characteristics of the MIMI_LEMMS
instrument. To make use of it requires a C-kernel with coverage at the
epochs of interest be loaded.
The rotation matrix that takes vectors from the MIMI_LEMMS_ART frame to the
MIMI_LEMMS_BASE frame follows:
[ ] [ ]
[ ROT ] = [ ANGLE ]
[ ] [ ]
Z
where [x] represents the rotation matrix of a given angle x about
i
axis i, and ANGLE is the articulation angle.
\begindata
FRAME_CASSINI_MIMI_LEMMS_ART = -82764
FRAME_-82764_NAME = 'CASSINI_MIMI_LEMMS_ART'
FRAME_-82764_CLASS = 3
FRAME_-82764_CLASS_ID = -82764
FRAME_-82764_CENTER = -82
CK_-82764_SCLK = -82
CK_-82764_SPK = -82
\begintext
Magnetospheric Imaging Instrument Low Energy Magnetospheric Measurements 1
(MIMI_LEMMS1)
The Z-axis of this frame is the instrument boresight.
This frame requires one of two possible C-kernels:
-- One kernel connects this instrument frame (-82762) directly
to the spacecraft frame (-82000).
-- The other possible kernel connects this instrument frame
(-82762) to the articulation frame (-82764) defined above.
The kernel that makes this connection for all epochs after
launch is delivered with the kernel set. See the kernel
comments for details of the frame construction.
One should take care in the simultaneous loading of C-kernels that utilize
different paths of the frame tree to connect CASSINI_MIMI_LEMMS1 to
CASSINI_SC_COORD. See [1] for details regarding C-kernel precedence.
\begindata
FRAME_CASSINI_MIMI_LEMMS1 = -82762
FRAME_-82762_NAME = 'CASSINI_MIMI_LEMMS1'
FRAME_-82762_CLASS = 3
FRAME_-82762_CLASS_ID = -82762
FRAME_-82762_CENTER = -82
CK_-82762_SCLK = -82
CK_-82762_SPK = -82
\begintext
Magnetospheric Imaging Instrument Low Energy Magnetospheric Measurements 2
(MIMI_LEMMS2)
The Z-axis of this frame is the instrument boresight.
This frame requires one of two possible C-kernels:
-- One kernel connects this instrument frame (-82763) directly
to the spacecraft frame (-82000).
-- The other possible kernel connects this instrument frame
(-82763) to the articulation frame (-82764) defined above.
The kernel that makes this connection for all epochs after
launch is delivered with the kernel set. See the kernel
comments for details of the frame construction.
One should take care in the simultaneous loading of C-kernels that utilize
different paths of the frame tree to connect CASSINI_MIMI_LEMMS2 to
CASSINI_SC_COORD. See [1] for details regarding C-kernel precedence.
\begindata
FRAME_CASSINI_MIMI_LEMMS2 = -82763
FRAME_-82763_NAME = 'CASSINI_MIMI_LEMMS2'
FRAME_-82763_CLASS = 3
FRAME_-82763_CLASS_ID = -82763
FRAME_-82763_CENTER = -82
CK_-82763_SCLK = -82
CK_-82763_SPK = -82
\begintext
RADAR Frames
----------------------------------------------------------
Compiled from [23] and [5]:
The RADAR instrument consists of 5 beams in the following configuration:
^ Xsc
|
|
Ysc |
<------o
| Zsc
|
.
.
.
Beam 1 Beam 2 Beam 3 Beam 4 Beam 5
|
|-----x-----|-----x-----|----x----|-----x-----|-----x-----|
|
|-- 1.35 ---|-- 0.85 --|-- 0.85 --|-- 1.35 ---|
|
|
V
Beam 3 Direction
The above figure illustrates the separation in degrees between the beam
centers and their relation to the spacecraft frame.
Note the angles in the frame definitions are specified fro the ``from
instrument to (relative to) base frame'' transformation.
RADAR Beam 1 (RADAR_1)
RADAR Beam 1 is directed nominally 2.2 degrees off of the -Z axis of the
spacecraft in the direction of the +Y axis of the spacecraft frame. The
following definition encapsulates this frame:
From [23]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 177.8 ] [ 0.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RADAR_1 = -82810
FRAME_-82810_NAME = 'CASSINI_RADAR_1'
FRAME_-82810_CLASS = 4
FRAME_-82810_CLASS_ID = -82810
FRAME_-82810_CENTER = -82
TKFRAME_-82810_SPEC = 'ANGLES'
TKFRAME_-82810_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82810_ANGLES = ( 177.8, 0.0, 0.0 )
TKFRAME_-82810_AXES = ( 1, 2, 3 )
TKFRAME_-82810_UNITS = 'DEGREES'
\begintext
RADAR Beam 2 (RADAR_2)
RADAR Beam 2 is directed nominally 0.85 degrees off of the -Z axis of the
spacecraft in the direction of the +Y axis of the spacecraft frame. The
following definition encapsulates this frame:
From [23]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 179.15 ] [ 0.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
FRAME_CASSINI_RADAR_2 = -82811
FRAME_-82811_NAME = 'CASSINI_RADAR_2'
FRAME_-82811_CLASS = 4
FRAME_-82811_CLASS_ID = -82811
FRAME_-82811_CENTER = -82
TKFRAME_-82811_SPEC = 'ANGLES'
TKFRAME_-82811_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82811_ANGLES = ( 179.15, 0.0, 0.0 )
TKFRAME_-82811_AXES = ( 1, 2, 3 )
TKFRAME_-82811_UNITS = 'DEGREES'
From [44], the RADAR Beam 2 reference frame is to be adjusted to the
following:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 179.15 ] [ -1.2 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_RADAR_2 = -82811
FRAME_-82811_NAME = 'CASSINI_RADAR_2'
FRAME_-82811_CLASS = 4
FRAME_-82811_CLASS_ID = -82811
FRAME_-82811_CENTER = -82
TKFRAME_-82811_SPEC = 'ANGLES'
TKFRAME_-82811_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82811_ANGLES = ( 179.15, -1.2, 0.0 )
TKFRAME_-82811_AXES = ( 1, 2, 3 )
TKFRAME_-82811_UNITS = 'DEGREES'
\begintext
RADAR Beam 3 (RADAR_3)
RADAR Beam 3 is directed nominally along the -Z axis of the spacecraft
frame. The following definition encapsulates this frame:
From [23]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 180.0 ] [ 0.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RADAR_3 = -82812
FRAME_-82812_NAME = 'CASSINI_RADAR_3'
FRAME_-82812_CLASS = 4
FRAME_-82812_CLASS_ID = -82812
FRAME_-82812_CENTER = -82
TKFRAME_-82812_SPEC = 'ANGLES'
TKFRAME_-82812_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82812_ANGLES = ( 180.0, 0.0, 0.0 )
TKFRAME_-82812_AXES = ( 1, 2, 3 )
TKFRAME_-82812_UNITS = 'DEGREES'
\begintext
RADAR Beam 4 (RADAR_4)
RADAR Beam 4 is directed nominally 0.85 degrees off of the -Z axis of the
spacecraft in the direction of the -Y axis of the spacecraft frame. The
following definition encapsulates this frame:
From [23]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 180.85 ] [ 0.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RADAR_4 = -82813
FRAME_-82813_NAME = 'CASSINI_RADAR_4'
FRAME_-82813_CLASS = 4
FRAME_-82813_CLASS_ID = -82813
FRAME_-82813_CENTER = -82
TKFRAME_-82813_SPEC = 'ANGLES'
TKFRAME_-82813_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82813_ANGLES = ( 180.85, 0.0, 0.0 )
TKFRAME_-82813_AXES = ( 1, 2, 3 )
TKFRAME_-82813_UNITS = 'DEGREES'
\begintext
From [44], the RADAR Beam 4 reference frame is to be adjusted to the
following:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 180.85 ] [ -1.2 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
\begindata
FRAME_CASSINI_RADAR_4 = -82813
FRAME_-82813_NAME = 'CASSINI_RADAR_4'
FRAME_-82813_CLASS = 4
FRAME_-82813_CLASS_ID = -82813
FRAME_-82813_CENTER = -82
TKFRAME_-82813_SPEC = 'ANGLES'
TKFRAME_-82813_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82813_ANGLES = ( 180.85, -1.2, 0.0 )
TKFRAME_-82813_AXES = ( 1, 2, 3 )
TKFRAME_-82813_UNITS = 'DEGREES'
\begintext
RADAR Beam 5 (RADAR_5)
RADAR Beam 5 is directed nominally 2.2 degrees off of the -Z axis of the
spacecraft in the direction of the -Y axis of the spacecraft frame. The
following definition encapsulates this frame:
From [23]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 182.2 ] [ 0.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RADAR_5 = -82814
FRAME_-82814_NAME = 'CASSINI_RADAR_5'
FRAME_-82814_CLASS = 4
FRAME_-82814_CLASS_ID = -82814
FRAME_-82814_CENTER = -82
TKFRAME_-82814_SPEC = 'ANGLES'
TKFRAME_-82814_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82814_ANGLES = ( 182.2, 0.0, 0.0 )
TKFRAME_-82814_AXES = ( 1, 2, 3 )
TKFRAME_-82814_UNITS = 'DEGREES'
\begintext
RPWS Frames
----------------------------------------------------------
The RPWS antennae are located roughly on the +Y side of the Cassini
orbiter, while the RPWS Langmuir Probe is roughly located on the -X side.
Note the angles in the frame definitions are specified for the ``from
instrument to (relative to) base frame'' transformation.
Radio and Plasma Wave Science (RPWS)
As [17] indicates, the ``collective'' RPWS boresight is nominally directed
along the spacecraft +Y axis. Utilizing the Euler angles specified in this
email, we obtain the following frame definition:
From [17]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 180.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
X Y Z
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RPWS = -82730
FRAME_-82730_NAME = 'CASSINI_RPWS'
FRAME_-82730_CLASS = 4
FRAME_-82730_CLASS_ID = -82730
FRAME_-82730_CENTER = -82
TKFRAME_-82730_SPEC = 'ANGLES'
TKFRAME_-82730_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82730_ANGLES = ( 180.0, -90.0, 0.0 )
TKFRAME_-82730_AXES = ( 3, 1, 3 )
TKFRAME_-82730_UNITS = 'DEGREES'
\begintext
Radio and Plasma Wave Science Electric Antenna System (RPWS_E[AXIS][SIGN])
From [24]:
``The RPWS electric antenna system is a triad of 10-meter conducting
monopoles, symmetric about the Y-Z plane. Two of the elements are extended
in a 120-degree "V" on either side of the magnetometer boom (i.e., the S/C
Y-axis) and in a plane which is rotated up from the S/C X-Y plane
containing the magnetometer boom by 37 degrees. These two elements are
referred to as the EXPLUS and EXMINUS sensors. The third element is
extended downward in the S/C Y-Z plane at an angleof 37 degrees from the
S/C +Z axis. That said, it now should be explained that the "electrical"
characteristics of these three antennas deviate from the physical alignment
and lengths of the elements due to the complex ground plane provided by the
spacecraft. It is these electrical characteristics that the three RPWS
Frame definitions RPWS_EXPLUS, RPWS_EXMINUS, and RPWS_EZPLUS are intended
to specify. Based upon model rheometry experiments, in which a model of the
Cassini Spacecraft with fully extended RPWS antennas was immersed in a tank
filled with an electrolytic, the following estimates have been made for the
electrical axes of the three antenna elements:
Frame Frame Z-Axis in CASSINI_SC_COORD "boresight"
------ --------------------------------
RPWS_EXPLUS [ 0.91202578, 0.27709462, -0.30236989 ]
RPWS_EXMINUS [ -0.91202578, 0.27709462, -0.30236989 ]
RPWS_EZPLUS [ -0.01091120, 0.52089537, 0.85355080 ]
These numbers may change after the RPWS Jupiter Calibrations.''
Antenna Frame Definitions:
From [14]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -16.9 ] [ -107.6 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RPWS_EXPLUS = -82731
FRAME_-82731_NAME = 'CASSINI_RPWS_EXPLUS'
FRAME_-82731_CLASS = 4
FRAME_-82731_CLASS_ID = -82731
FRAME_-82731_CENTER = -82
TKFRAME_-82731_SPEC = 'ANGLES'
TKFRAME_-82731_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82731_ANGLES = ( -16.9, -107.6, 0.0 )
TKFRAME_-82731_AXES = ( 3, 2, 1 )
TKFRAME_-82731_UNITS = 'DEGREES'
\begintext
From [14]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -163.1 ] [ -107.6 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RPWS_EXMINUS= -82732
FRAME_-82732_NAME = 'CASSINI_RPWS_EXMINUS'
FRAME_-82732_CLASS = 4
FRAME_-82732_CLASS_ID = -82732
FRAME_-82732_CENTER = -82
TKFRAME_-82732_SPEC = 'ANGLES'
TKFRAME_-82732_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82732_ANGLES = (-163.1, -107.6, 0.0 )
TKFRAME_-82732_AXES = ( 3, 2, 1 )
TKFRAME_-82732_UNITS = 'DEGREES'
\begintext
From [14]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ -91.2 ] [ -31.4 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RPWS_EZPLUS = -82733
FRAME_-82733_NAME = 'CASSINI_RPWS_EZPLUS'
FRAME_-82733_CLASS = 4
FRAME_-82733_CLASS_ID = -82733
FRAME_-82733_CENTER = -82
TKFRAME_-82733_SPEC = 'ANGLES'
TKFRAME_-82733_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82733_ANGLES = ( -91.2, -31.4, 0.0 )
TKFRAME_-82733_AXES = ( 3, 2, 1 )
TKFRAME_-82733_UNITS = 'DEGREES'
\begintext
Radio and Plasma Wave Science Langmuir Probe (RPWS_LP)
From [24]:
``The RPWS Langmuir Probe is on the -X side of the spacecraft and can sense
roughly the entire hemisphere defined by the RPWS_LP Frame.''
From [14]:
[ ] [ ] [ ] [ ]
[ ROT ] = [ 180.0 ] [ -90.0 ] [ 0.0 ]
[ ] [ ] [ ] [ ]
Z Y X
where [x] represents the rotation matrix of a given angle x about
i
axis i.
Nominal Frame Definition:
\begindata
FRAME_CASSINI_RPWS_LP = -82734
FRAME_-82734_NAME = 'CASSINI_RPWS_LP'
FRAME_-82734_CLASS = 4
FRAME_-82734_CLASS_ID = -82734
FRAME_-82734_CENTER = -82
TKFRAME_-82734_SPEC = 'ANGLES'
TKFRAME_-82734_RELATIVE = 'CASSINI_SC_COORD'
TKFRAME_-82734_ANGLES = ( 180.0, -90.0, 0.0 )
TKFRAME_-82734_AXES = ( 3, 2, 1 )
TKFRAME_-82734_UNITS = 'DEGREES'
\begintext