generated from NASA-AMMOS/aerie-mission-model-template
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathpck00011.tpc
4318 lines (2649 loc) · 128 KB
/
pck00011.tpc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
KPL/PCK
P_constants (PCK) SPICE kernel file pck00011.tpc
===========================================================================
By: Nat Bachman (NAIF) 2022 December 27
Toolkit Compatibility Warning
--------------------------------------------------------
This file provides Mars system rotation data usable with the
N0067 and newer versions of the SPICE Toolkit. Using it to compute
Mars, Phobos, or Deimos orientation with Toolkit versions N0066
or earlier may cause fatal run-time memory corruption in user
programs. See "Software limitations" below.
All other data are compatible with the N0066 and earlier Toolkits.
NAIF provides the PCK file pck00011_n0066.tpc for use with
older Toolkits. That PCK contains all the data from this file,
except that, in that file, one of the phase angle polynomials
for Phobos is truncated to first order.
Purpose
--------------------------------------------------------
This file makes available for use in SPICE-based application
software orientation and size/shape data for natural bodies. The
principal source of the data is a published report by the IAU
Working Group on Cartographic Coordinates and Rotational Elements
[1].
Orientation and size/shape data not provided by this file may be
available in mission-specific PCK files. Such PCKs may be the
preferred data source for mission-related applications.
Mission-specific PCKs can be found in PDS archives or on the NAIF
web site at URL:
https://naif.jpl.nasa.gov/naif/data.html
Version Description
--------------------------------------------------------
This file was created on December 27, 2022 by NASA's Navigation
and Ancillary Information Facility (NAIF) group, located at the Jet
Propulsion Laboratory, Pasadena, CA.
The previous version of the file was
pck00010.tpc
That file was published October 21, 2011.
This version incorporates data from sources listed under "Sources and
References" below. The primary sources are [1] and [2]. This file
contains size, shape, and orientation data for all objects covered
by the previous version of the file.
New objects covered by this file but not by the previous
version are:
Asteroid 52 Europa
Comet 67P/Churyumov-Gerasimenko
Aegaeon (Saturn LIII)
Comet Hartley 2
Asteroid Psyche
Orientation data for the following objects provided by this file differ
from those provided by the previous version:
Mercury
Mars
Deimos
Phobos
Neptune
Ceres
Steins
Vesta
Borrelly
Tempel 1
Radii for the following objects provided by this file differ
from those provided by the previous version:
Sun
Mercury
Anthe
Atlas
Calypso
Daphnis
Epimetheus
Helene
Janus
Methone
Pallene
Pan
Pandora
Prometheus
Telesto
Pluto
Charon
Itokawa
File Organization
--------------------------------------------------------
The contents of this file are as follows.
Introductory Information:
-- Purpose
-- Version description
-- File Organization
-- Disclaimer
-- Sources
-- Explanatory notes
-- Body numbers and names
PcK Data:
Orientation Data
----------------
-- Orientation constants for the Sun, planets, and
Pluto. Additional items included in this section:
- North geomagnetic centered dipole value
for the year 2023
-- Orientation constants for satellites
-- Orientation constants for asteroids
52 Europa
Davida
Eros
Gaspra
Hartley 2 (data shown in comments only)
Ida
Itokawa
Lutetia
Pallas
Steins
Vesta
-- Orientation constants for comets
19P/Borrelly
67P/Churyumov-Gerasimenko
Hartley 2 (data shown in comments only)
9P/Tempel 1
Orientation data provided in this file are used
by the SPICE Toolkit to evaluate the orientation
of body-fixed, body-centered reference frames
with respect to the ICRF frame ("J2000" in
SPICE documentation). These body-fixed frames
have names of the form
IAU_<body name>
for example
IAU_JUPITER
See the PCK Required Reading file pck.req for details.
Radii of Bodies
---------------
-- Radii of Sun, planets, and Pluto
-- Radii of satellites, where available
-- Radii of asteroids
52 Europa
Ceres
Davida
Eros
Gaspra
Ida
Itokawa
Lutetia
Mathilde
Psyche
Steins
Toutatis
Vesta
-- Radii of comets
19P/Borrelly
67P/Churyumov-Gerasimenko
81P/Wild 2
9P/Tempel 1
Halley
Hartley 2
Disclaimer
--------------------------------------------------------
Applicability of Data
This P_constants file (PCK) may not contain the parameter values
that you prefer. NAIF suggests that you inspect this file visually
before proceeding with any critical or extended data processing.
File Modifications by Users
Note that this file may be readily modified by you to change
values or add/delete parameters. NAIF requests that you update the
"by line," date, version description section, and file name
if you modify this file.
A user-modified file should be thoroughly tested before
being published or otherwise distributed.
P_constants files must conform to the standards described
in the two SPICE technical reference documents:
PCK Required Reading
Kernel Required Reading
Known Limitations and Caveats
Accuracy
--------
In general, the orientation models given here are claimed by the
IAU Working Group Report [1] to be accurate to 0.1 degree
([1], p. 9). However, NAIF notes that orientation models for
natural satellites and asteroids have in some cases changed
substantially with the availability of new observational data, so
users are urged to investigate the suitability for their
applications of the models presented here.
Earth orientation
-----------------
The IAU report [1] no longer provides rotational elements for the
Earth. Data in this file are from [3].
NAIF strongly cautions against using the earth rotation model
presented here, corresponding to the SPICE reference frame name
IAU_EARTH, for work demanding high accuracy. This model has been
determined by NAIF to have an error in the prime meridian location
of magnitude at least 150 arcseconds, with a local minimum
occurring during the year 1999. Regarding availability of better
earth orientation data for use with the SPICE system:
Earth orientation data are available from NAIF in the form of
binary earth PCK files. These files provide orientation data
for the ITRF93 (terrestrial) reference frame relative to the
ICRF.
NAIF employs an automated process to create these files; each
time JPL's Tracking Systems and Applications Section produces a
new earth orientation parameter (EOP) file, a new PCK is
produced. These PCKs cover a roughly 23 year time span starting
at Jan. 1, 2000. In these PCK files, the following effects are
accounted for in modeling the earth's rotation:
- Precession: 1976 IAU model
- Nutation: 1980 IAU model, plus interpolated
EOP nutation corrections
- Polar motion: interpolated from EOP file
- True sidereal time:
UT1 - UT1R (if needed): given by analytic formula
+ TAI - UT1 (or UT1R): interpolated from EOP file
+ UT1 - GMST: given by analytic formula
+ equation of equinoxes: given by analytic formula
where
TAI = International Atomic Time
UT1 = Greenwich hour angle of computed mean sun - 12h
UT1R = Regularized UT1
GMST = Greenwich mean sidereal time
These kernels are available from the NAIF web site
https://naif.jpl.nasa.gov/pub/naif/generic_kernels/pck
At this time, these kernels have file names of the form
earth_000101_yymmdd_yymmdd.bpc
The first date in the file name, meaning 2000 January 1, is the
file's coverage begin time. The second and third dates are,
respectively, the file's coverage end time and the epoch of the
last datum.
These binary PCK files are very accurate (error < 0.1
microradian) for epochs preceding the epoch of the last datum.
For later epochs, the error rises to several microradians.
Binary PCK files giving accurate earth orientation from 1972 to
2007 and *low accuracy* predicted earth orientation from
2020 to 2099 are also available in the same location.
Characteristics and names of the binary kernels described here
are subject to change. See the aareadme.txt file at the URL
above for details.
Lunar orientation
-----------------
The IAU report [1] no longer provides rotational elements for the
Moon. Data in this file are from [3].
The lunar orientation formula provided by this file is a
trigonometric polynomial approximation yielding the orientation of
the lunar "Mean Earth/Polar Axis" (ME) reference frame. The
SPICE reference frame name corresponding to this model is
IAU_MOON.
A more accurate approximation can be obtained by using both the
latest NAIF lunar frame kernel and the latest binary lunar orientation
PCK file. These files provide orientation data for the both the Mean
Earth/Polar Axis frame, which has the SPICE name MOON_ME, and the
Lunar Principal Axes frame, which has the SPICE name MOON_PA.
These files are available on the NAIF web site; lunar PCKs are
located at the PCK URL above; lunar frame kernels are located at
https://naif.jpl.nasa.gov/pub/naif/generic_kernels/fk/satellites
The latest lunar frame kernel has a name of the form
moon_dennn_yymmdd.tf
The latest binary lunar PCK has a name of the form
moon_pa_dennn_yymmdd.bpc
See the "aareadme.txt" files in the paths shown above for details
on file contents and versions. We also suggest you refer to the
SPICE tutorial named "lunar_earth_pck-fk," which is available from
the NAIF web site.
Geomagnetic dipole
------------------
The SPICE Toolkit doesn't currently contain software to model the
north geomagnetic centered dipole as a function of time.
As a convenience for users, this dipole's location at the
epoch 2023.0 was selected as a representative datum, and the
planetocentric longitude and latitude of this location have been
associated with the keywords
BODY399_N_GEOMAG_CTR_DIPOLE_LON
BODY399_N_GEOMAG_CTR_DIPOLE_LAT
Older values for the north geomagnetic centered dipole are
presented in comments as a discrete time series for the time range
1945-2000. For details concerning the geomagnetic field model from
which these values were derived, including a discussion of the
model's accuracy, see [9] and [11].
Prime meridian offsets
----------------------
Prime meridian offset kernel variables, which have names
of the form
BODYnnn_LONG_AXIS
are not used by SPICE geometry software. These variables should be
considered deprecated; however, they will be retained for
backwards compatibility.
Users wishing to specify an offset reflecting the orientation of a
reference ellipsoid relative to a body-fixed reference frame
specified here should do so by creating a constant-offset frame
(also called a "TK" frame) specification. See the Frames Required
Reading frames.req for details.
The Mars prime meridian offset given by [6] is provided for
informational purposes only.
Software limitations
--------------------
SPICE Toolkits prior to version N0067 cannot make use of
the Mars system orientation data provided in this file. These
older Toolkits are unable to detect and signal a SPICE error if
they are used to compute orientation of Mars, Phobos, or Deimos
using these data: memory corruption will occur in user applications
linked these Toolkits if the applications attempt such computations.
Any results, including those of unrelated computations, may be invalid
after such memory corruption occurs.
Sources and References
--------------------------------------------------------
Sources and background references for the constants listed in this
file are:
[1] Archinal, B.A., Acton, C.H., A'Hearn, M.F., Conrad, A.,
Consolmagno, G.J., Duxbury, T., Hestroffer, D., Hilton,
J.L., Kirk, R.L., Klinoner, S.A., McCarthy, D.,
Meech, K., Oberst, J., Ping., J., Seidelmann, P.K., Tholen,
D.J., Thomas, P.C., and Williams, I.P., "Report of the IAU
Working Group on Cartographic Coordinates and Rotational
Elements: 2015," Celestial Mechanics and Dynamical Astronomy
130, Article number 22 (2018).
DOI: https://doi.org/10.1007/s10569-017-9805-5
[2] Archinal, B.A., Acton, C.H., Conrad, A., Duxbury, T.,
Hestroffer, D., Hilton, J.L., Jorda, L., Kirk, R.L.,
Klinoner, Margot, J.-L., S.A., Meech, K., Oberst,
Paganelli, F., J., Ping., J., Seidelmann, P.K., Stark, A.,
Tholen, Wang, Y., and Williams, I.P., "Correction to:
Report of the IAU Working Group on Cartographic Coordinates
and Rotational Elements: 2015."
[3] Archinal, B.A., A'Hearn, M.F., Bowell, E., Conrad, A.,
Consolmagno, G.J., Courtin, R., Fukushima, T.,
Hestroffer, D., Hilton, J.L., Krasinsky, G.A.,
Neumann, G., Oberst, J., Seidelmann, P.K., Stooke, P.,
Tholen, D.J., Thomas, P.C., and Williams, I.P.
"Report of the IAU Working Group on Cartographic Coordinates
and Rotational Elements: 2009."
[4] Archinal, B.A., A'Hearn, M.F., Conrad, A.,
Consolmagno, G.J., Courtin, R., Fukushima, T.,
Hestroffer, D., Hilton, J.L., Krasinsky, G.A.,
Neumann, G., Oberst, J., Seidelmann, P.K., Stooke, P.,
Tholen, D.J., Thomas, P.C., and Williams, I.P.
"Erratum to: Reports of the IAU Working Group on
Cartographic Coordinates and Rotational Elements: 2006 &
2009."
[5] Seidelmann, P.K., Archinal, B.A., A'Hearn, M.F.,
Conrad, A., Consolmagno, G.J., Hestroffer, D.,
Hilton, J.L., Krasinsky, G.A., Neumann, G.,
Oberst, J., Stooke, P., Tedesco, E.F., Tholen, D.J.,
and Thomas, P.C. "Report of the IAU/IAG Working Group
on Cartographic Coordinates and Rotational Elements: 2006."
[6] Duxbury, Thomas C. (2001). "IAU/IAG 2000 Mars Cartographic
Conventions," presentation to the Mars Express Data
Archive Working Group, Dec. 14, 2001.
[7] Russell, C.T. and Luhmann, J.G. (1990). "Earth: Magnetic
Field and Magnetosphere." <http://www-ssc.igpp.ucla.
edu/personnel/russell/papers/earth_mag>. Originally
published in "Encyclopedia of Planetary Sciences," J.H.
Shirley and R.W. Fainbridge, eds. Chapman and Hall,
New York, pp 208-211.
[8] Russell, C.T. (1971). "Geophysical Coordinate
Transformations," Cosmic Electrodynamics 2 184-186.
NAIF document 181.0.
[9] ESA/ESTEC Space Environment Information System (SPENVIS)
(2003). Web page: "Dipole approximations of the
geomagnetic field." <https://www.spenvis.oma.be/help/
background/magfield/cd.html>.
[10] Davies, M.E., Abalakin, V.K., Bursa, M., Hunt, G.E.,
and Lieske, J.H. (1989). "Report of the IAU/IAG/COSPAR
Working Group on Cartographic Coordinates and Rotational
Elements of the Planets and Satellites: 1988," Celestial
Mechanics and Dynamical Astronomy, v.46, no.2, pp.
187-204.
[11] International Association of Geomagnetism and Aeronomy
Web page: "International Geomagnetic Reference Field."
Discussion URL:
http://www.ngdc.noaa.gov/IAGA/vmod/igrf.html
Coefficients URL:
https://www.ngdc.noaa.gov/IAGA/vmod/coeffs/igrf13coeffs.txt
[12] Email communication from Dr. Brent Archinal (IAU WGCCRE Chair,
USGS): "Re: Shape of comet Hartley 2." Dated December 22, 2022.
[13] Seidelmann, P.K., Archinal, B.A., A'Hearn, M.F.,
Cruikshank, D.P., Hilton, J.L., Keller, H.U., Oberst, J.,
Simon, J.L., Stooke, P., Tholen, D.J., and Thomas, P.C.
"Report of the IAU/IAG Working Group on Cartographic
Coordinates and Rotational Elements of the Planets and
Satellites: 2003," Unpublished.
Most values are from [1]. All exceptions are
commented where they occur in this file. The exceptions are:
-- Phobos prime meridian constants are from [2].
-- Lunar orientation data are from [3].
-- Earth orientation data are from [3].
-- North geomagnetic centered dipole values were
computed by Nat Bachman from the 13th generation IGRF.
The data source was [11].
"Old values" listed are from the SPICE PCK file pck00010.tpc
dated October 21, 2011. Most of these values came from the 2009
IAU report [3].
Explanatory Notes
--------------------------------------------------------
This file, which is logically part of the SPICE P-kernel, contains
constants used to model the orientation, size and shape of the
Sun, planets, natural satellites, and selected comets and
asteroids. The orientation models express the direction of the
pole and location of the prime meridian of a body as a function of
time. The size/shape models ("shape models" for short) represent
all bodies as ellipsoids, using two equatorial radii and a polar
radius. Spheroids and spheres are obtained when two or all three
radii are equal.
The SPICE Toolkit routines that use this file are documented in
the SPICE "Required Reading" file pck.req. They are also
documented in the "PCK" SPICE tutorial, which is available on
the NAIF web site.
File Format
A terse description of the PCK file format is given here. See the
SPICE "Required Reading" files pck.req and kernel.req for a
detailed explanation of the SPICE text kernel file format. The
files pck.req and kernel.req are included in the documentation
provided with the SPICE Toolkit.
The file starts out with the ``ID word'' string
KPL/PCK
This string identifies the file as a text kernel containing PCK
data.
This file consists of a series of comment blocks and data blocks.
Comment blocks, which contain free-form descriptive or explanatory
text, are preceded by a \begintext token. Data blocks follow a
\begindata token. In order to be recognized, each of these tokens
must be placed on a line by itself.
The portion of the file preceding the first data block is treated
as a comment block; it doesn't require an initial \begintext
token.
This file identifies data using a series of
KEYWORD = VALUE
assignments. The left hand side of each assignment is a
"kernel variable" name; the right hand side is an associated value
or list of values. SPICE kernel pool access routines (see kernel.req)
enable other SPICE routines and user applications to retrieve the
set of values associated with each kernel variable name.
Kernel variable names are case-sensitive and are limited to
32 characters in length.
Numeric values may be integer or floating point. String values
are normally limited to 80 characters in length; however, SPICE
provides a mechanism for identifying longer, "continued" strings.
See the SPICE routine STPOOL for details.
String values are single quoted.
When the right hand side of an assignment is a list of values,
the list items may be separated by commas or simply by blanks.
The list must be bracketed by parentheses. Example:
BODY399_RADII = ( 6378.1366 6378.1366 6356.7519 )
Any blanks preceding or following keyword names, values and equal
signs are ignored.
Assignments may be spread over multiple lines, for example:
BODY399_RADII = ( 6378.1366
6378.1366
6356.7519 )
This file may contain blank lines anywhere. Non-printing
characters including TAB should not be present in the file: the
presence of such characters may cause formatting errors when the
file is viewed.
Time systems and reference frames
The 2015 IAU Working Group Report [1] states the time scale used
as the independent variable for the rotation formulas is
Barycentric Dynamical Time (TDB) and that the epoch of variable
quantities is J2000 TDB (2000 Jan 1 12:00:00 TDB, Julian ephemeris
date 2451545.0 TDB). Throughout SPICE documentation and in this
file, we use the names "J2000 TDB" and "J2000" for this epoch. The
name "J2000.0" is equivalent.
SPICE documentation refers to the time system used in this file
as either "ET" or "TDB." SPICE software makes no distinction
between TDB and the time system associated with the independent
variable of the JPL planetary ephemerides T_eph.
The inertial reference frame used for the rotational elements in
this file is identified by [1] as the ICRF (International
Celestial Reference Frame).
The SPICE PCK software that reads this file uses the label "J2000"
to refer to the ICRF; this is actually a mislabeling which has
been retained in the interest of backward compatibility. Using
data from this file, by means of calls to the SPICE frame
transformation routines, will actually compute orientation
relative to the ICRF.
The difference between the J2000 frame and the ICRF is
on the order of 100 milliarcseconds and is well below the
accuracy level of the formulas in this file.
Orientation models
All of the complete orientation models use three Euler angles to
describe the orientation of the coordinate axes of the "Body Equator
and Prime Meridian" system with respect to an inertial system. By
default, the inertial system is the ICRF (labeled as "J2000"), but
other inertial frames can be specified in the file. See the PCK
Required Reading for details.
The first two angles, in order, are the ICRF right ascension and
declination (henceforth RA and DEC) of the north pole of a body as
a function of time. The third angle is the prime meridian location
(represented by "W"), which is expressed as a rotation about the
north pole, and is also a function of time.
For each body, the expressions for the north pole's right
ascension and declination, as well as prime meridian location, are
sums (as far as the models that appear in this file are concerned)
of quadratic polynomials and trigonometric polynomials, where the
independent variable is time.
In this file, the time arguments in expressions always refer to
Barycentric Dynamical Time (TDB), measured in centuries or days
past a reference epoch. By default, the reference epoch is the
J2000 epoch, which is Julian ephemeris date 2451545.0 (2000 Jan 1
12:00:00 TDB), but other epochs can be specified in the file. See
the PCK Required Reading for details.
Orientation models for satellites and some planets (including
Jupiter) involve both polynomial terms and trigonometric terms.
The arguments of the trigonometric terms are linear or quadratic
polynomials. In this file, we call the arguments of these
trigonometric terms "nutation precession angles" or "phase angles."
Example: 2015 IAU Model for orientation of Jupiter. Note that
these values are used as an example only; see the data area below
for current values.
Right ascension
---------------
alpha = 268.056595 - 0.006499 T + 0.000117 sin(Ja)
0 + 0.000938 sin(Jb) + 0.001432 sin(Jc)
+ 0.000030 sin(Jd) + 0.002150 sin(Je)
Declination
-----------
delta = 64.495303 + 0.002413 T + 0.000050 cos(Ja)
0 + 0.000404 cos(Jb) + 0.000617 cos(Jc)
- 0.000013 cos(Jd) + 0.000926 cos(Je)
Prime meridian
--------------
W = 284.95 + 870.5366420 d
Here
T represents centuries past J2000 ( TDB ),
d represents days past J2000 ( TDB ).
Ja-Je are nutation precession angles.
In this file, the polynomials' coefficients above are assigned
to kernel variable names (left-hand-side symbols) as follows
BODY599_POLE_RA = ( 268.056595 -0.006499 0. )
BODY599_POLE_DEC = ( 64.495303 0.002413 0. )
BODY599_PM = ( 284.95 870.5360000 0. )
and the trigonometric polynomials' coefficients are assigned
as follows
BODY599_NUT_PREC_RA = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.000117
0.000938
0.001432
0.000030
0.002150 )
BODY599_NUT_PREC_DEC = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.000050
0.000404
0.000617
-0.000013
0.000926 )
BODY599_NUT_PREC_PM = ( 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.0
0.0
0.0
0.0
0.0 )
Note the number "599"; this is the NAIF ID code for Jupiter.
In this file, the polynomial expressions for the nutation
precession angles are listed along with the planet's RA, DEC, and
prime meridian terms. Below are the 2006 IAU nutation precession
angles for the Jupiter system.
J1 = 73.32 + 91472.9 T
J2 = 24.62 + 45137.2 T
J3 = 283.90 + 4850.7 T
J4 = 355.80 + 1191.3 T
J5 = 119.90 + 262.1 T
J6 = 229.80 + 64.3 T
J7 = 352.25 + 2382.6 T
J8 = 113.35 + 6070.0 T
J9 = 146.64 + 182945.8 T
J10 = 49.24 + 90274.4 T
Ja = 99.360714 + 4850.4046 T
Jb = 175.895369 + 1191.9605 T
Jc = 300.323162 + 262.5475 T
Jd = 114.012305 + 6070.2476 T
Je = 49.511251 + 64.3000 T
Here
T represents centuries past J2000 ( TDB )
J1-J10 and Ja-Je are the nutation precession angles. The angles
J9 and J10 are equal to 2*J1 and 2*J2, respectively.
Angles J9 and J10 are not present in [1]; they have been added
to fit the terms 2*J1 and 2*J2, which appear in the orientation
models of several satellites, into a form that can be accepted
by the PCK system.
The assignment of the nutation precession angles for the
Jupiter system is as follows:
BODY5_NUT_PREC_ANGLES = ( 73.32 91472.9
24.62 45137.2
283.90 4850.7
355.80 1191.3
119.90 262.1
229.80 64.3
352.25 2382.6
113.35 6070.0
146.64 182945.8
49.24 90274.4
99.360714 4850.4046
175.895369 1191.9605
300.323162 262.5475
114.012305 6070.2476
49.511251 64.3000 )
You'll see an additional symbol grouped with the ones listed
above; it is
BODY599_LONG_AXIS
This is a deprecated feature; see the note on "Prime meridian
offsets" under "Known Limitations and Caveats" above.
The pattern of the formulas for satellite orientation is similar
to that for Jupiter. Example: 2006 IAU values for Io. Again, these
values are used as an example only; see the data area below for
current values.
Right ascension
---------------
alpha = 268.05 - 0.009 T + 0.094 sin(J3) + 0.024 sin(J4)
0
Declination
-----------
delta = 64.50 + 0.003 T + 0.040 cos(J3) + 0.011 cos(J4)
0
Prime meridian
--------------
W = 200.39 + 203.4889538 d - 0.085 sin(J3) - 0.022 sin(J4)
d represents days past J2000.
J3 and J4 are nutation precession angles.
The polynomial terms are assigned to symbols by the statements
BODY501_POLE_RA = ( 268.05 -0.009 0. )
BODY501_POLE_DEC = ( 64.50 0.003 0. )
BODY501_PM = ( 200.39 203.4889538 0. )
The coefficients of the trigonometric terms are assigned to symbols by
the statements
BODY501_NUT_PREC_RA = ( 0. 0. 0.094 0.024 )
BODY501_NUT_PREC_DEC = ( 0. 0. 0.040 0.011 )
BODY501_NUT_PREC_PM = ( 0. 0. -0.085 -0.022 )
501 is the NAIF ID code for Io.
SPICE software expects the models for satellite orientation to
follow the form of the model shown here: the polynomial portions of the
RA, DEC, and W expressions are expected to be quadratic, the
trigonometric terms for RA and W (satellite prime meridian) are expected
to be linear combinations of sines of nutation precession angles, the
trigonometric terms for DEC are expected to be linear combinations of
cosines of nutation precession angles, and the polynomials for the
nutation precession angles themselves are expected to be linear or
quadratic.
Eventually, the software will handle more complex expressions, we
expect.
Shape models
There is only one kind of shape model supported by the SPICE
Toolkit software at present: the triaxial ellipsoid. The 2015 IAU
report [1] does not use any other models, except in the case of
Mars, where separate values are given for the north and south
polar radii. In this file, we provide as a datum the mean Mars
polar radius provided by [1]. The North and South values are
included as comments.
For each body, three radii are listed: The first number is
the largest equatorial radius, the second number is the smaller
equatorial radius, and the third is the polar radius.
Example: Radii of the Earth.
BODY399_RADII = ( 6378.1366 6378.1366 6356.7519 )
Body Numbers and Names
--------------------------------------------------------
The following NAIF body ID codes and body names appear in this
file. See the NAIF IDs Required Reading file naif_ids.req for
a detailed discussion and a complete list of ID codes and names.
1 Mercury barycenter
2 Venus barycenter
3 Earth barycenter
4 Mars barycenter
5 Jupiter barycenter
6 Saturn barycenter
7 Uranus barycenter
8 Neptune barycenter
9 Pluto barycenter
10 Sun
199 Mercury
299 Venus
399 Earth
301 Moon
499 Mars
401 Phobos 402 Deimos
599 Jupiter
501 Io 502 Europa 503 Ganymede 504 Callisto
505 Amalthea 506 Himalia 507 Elara 508 Pasiphae
509 Sinope 510 Lysithea 511 Carme 512 Ananke
513 Leda 514 Thebe 515 Adrastea 516 Metis
699 Saturn
601 Mimas 602 Enceladus 603 Tethys 604 Dione
605 Rhea 606 Titan 607 Hyperion 608 Iapetus
609 Phoebe 610 Janus 611 Epimetheus 612 Helene
613 Telesto 614 Calypso 615 Atlas 616 Prometheus
617 Pandora 618 Pan 632 Methone 633 Pallene
634 Polydeuces 635 Daphnis 649 Anthe 653 Aegaeon
799 Uranus
701 Ariel 702 Umbriel 703 Titania 704 Oberon
705 Miranda 706 Cordelia 707 Ophelia 708 Bianca
709 Cressida 710 Desdemona 711 Juliet 712 Portia
713 Rosalind 714 Belinda 715 Puck
899 Neptune
801 Triton 802 Nereid 803 Naiad 804 Thalassa
805 Despina 806 Galatea 807 Larissa 808 Proteus
999 Pluto
901 Charon
1000005 Comet 19P/Borrelly
1000012 Comet 67P/Churyumov-Gerasimenko
1000036 Comet Halley
1000041 Comet Hartley 2
1000093 Comet 9P/Tempel 1
1000107 Comet 81P/Wild 2
2000001 Asteroid Ceres
2000002 Asteroid Pallas
2000016 Asteroid Psyche
2000004 Asteroid Vesta
2000021 Asteroid Lutetia
2000052 Asteroid 52 Europa
2000216 Asteroid Kleopatra
2000253 Asteroid Mathilde
2000433 Asteroid Eros
2000511 Asteroid Davida
2002867 Asteroid Steins
2004179 Asteroid Toutatis
2025143 Asteroid Itokawa
2431010 Asteroid Ida
9511010 Asteroid Gaspra
Orientation Constants for the Sun and Planets
--------------------------------------------------------
Sun
Old values:
Values are unchanged in the 2015 IAU report.
Current values: