KPL/PCK \begindata CASSINI_PCK_VERSION = ( '2004-DEC-09' ) \begintext P_constants (PcK) SPICE kernel file Refer to the notes at the bottom of the file for help, contacts, version history, references, and Cassini-specific parameter descriptions. All radii and orientation values are from reference [1] unless otherwise noted. This file was created by separating science controlled values from NAVT controlled values for ease of file maintenance. References to GMs provided by the NAVT, Saturn Pole RA and DEC, and JCOEFF and SCOEFF have been removed. -------- SUN Value for the Sun radii is from [2], page K7. \begindata BODY10_RADII = ( 696000. 696000. 696000. ) BODY10_POLE_RA = ( 286.13 0. 0. ) BODY10_POLE_DEC = ( 63.87 0. 0. ) BODY10_PM = ( 84.10 +14.18440 0. ) BODY10_LONG_AXIS = ( 0. ) \begintext -------- VENUS \begindata BODY299_RADII = ( 6051.8 6051.8 6051.8 ) BODY299_POLE_RA = ( 272.76 0. 0. ) BODY299_POLE_DEC = ( +67.16 0. 0. ) BODY299_PM = ( 160.20 -1.4813688 0. ) BODY299_LONG_AXIS = ( 0. ) \begintext -------- EARTH Northern hemisphere projection of the Earth's magnetic dipole: coordinates are planetocentric, values are from [3]. \begindata BODY399_RADII = ( 6378.140 6378.140 6356.75 ) BODY399_POLE_RA = ( 0. -0.641 0. ) BODY399_POLE_DEC = ( +90. -0.557 0. ) BODY399_PM = ( 190.147 +360.9856235 0. ) BODY399_LONG_AXIS = ( 0. ) BODY3_NUT_PREC_ANGLES = ( 125.045 -1935.5364525000 250.089 -3871.0729050000 260.008 475263.3328725000 176.625 487269.6299850000 357.529 35999.0509575000 311.589 964468.4993100001 134.963 477198.8693250000 276.617 12006.3007650000 34.226 63863.5132425000 15.134 -5806.6093575000 119.743 131.8406400000 239.961 6003.1503825000 25.053 473327.7964200000 ) BODY399_MAG_NORTH_POLE_LON = ( -69.761 ) BODY399_MAG_NORTH_POLE_LAT = ( 78.565 ) \begintext -------- JUPITER \begindata BODY599_RADII = ( 71492. 71492. 66854. ) BODY599_POLE_RA = ( 268.05 -0.009 0. ) BODY599_POLE_DEC = ( +64.49 +0.003 0. ) BODY599_PM = ( 284.95 +870.5366420 0. ) BODY599_LONG_AXIS = ( 0. ) 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 64.3 352.35 2382.6 113.35 6070.0 146.64 182945.8 49.24 90274.4 ) \begintext -------- SATURN The first seven angles given in NUT_PREC are the angles S1 through S7 from the 2000 IAU report; the eighth and ninth angles are 2*S1 and 2*S2, respectively. Ring models are from [4], [19], [20]. They are also documented in [11] and [12]. F Ring Data are from [8]. MIMI zone reflects the old flight rule for MIMI INCA, +/- 30000 km thickness inside of 8.74 Rs. BODY699_RADII_OPTICAL is for PDT to determine at what altitude that Saturn first starts to cast a discernible shadow. BODY699_RADII_RS models Saturn as a sphere and corresponds to a 100 mbar surface. BODY699_RADII and BODY699_RADII_1BAR correspond to a 1 bar surface. BODY699_RADII contains IAU values. BODY699_RADII_1BAR currently contains IAU values but will likely be updated during the mission. It is generally agreed that 60330.0 is the Saturn reference radius. This value in stored later in the file under the keyword RS. Eventually three different magnetospheric models will be provided. This section currently serves as a placeholder. BODY699_MAG_NORTH_POLE_LON = ( 0.0 ) BODY699_MAG_NORTH_POLE_LAT = ( +90.0 ) BODY699_M1COEF = ( 0.0 0.0 0.0 0.0) BODY699_G1COEF = ( 0.0 0.0 0.0 0.0) BODY699_H1COEF = ( 0.0 0.0 0.0 0.0) BODY699_M2COEF = ( 0.0 0.0 0.0 0.0) BODY699_G2COEF = ( 0.0 0.0 0.0 0.0) BODY699_H2COEF = ( 0.0 0.0 0.0 0.0) BODY699_M3COEF = ( 0.0 0.0 0.0 0.0) BODY699_G3COEF = ( 0.0 0.0 0.0 0.0) BODY699_H3COEF = ( 0.0 0.0 0.0 0.0) \begindata BODY699_RADII = ( 60268. 60268. 54364. ) BODY699_RADII_1BAR = ( 60268. 60268. 54364. ) BODY699_RADII_OPTICAL = ( 60430. 60430. 54508. ) BODY699_RADII_RS = ( 60330. 60330. 60330. ) BODY699_PM = ( 38.90 +810.7939024 0. ) BODY699_LONG_AXIS = ( 0. ) BODY6_NUT_PREC_ANGLES = ( 353.32 75706.7 28.72 75706.7 177.40 -36505.5 300.00 -7225.9 316.45 506.2 345.20 -1016.3 29.80 -52.1 706.64 151413.4 57.44 151413.4 ) BODY699_RING1_NAME = 'A Ring' BODY699_RING1 = (122170.0 136780.0 0.1 0.1 0.5) BODY699_RING1_1_NAME = 'Encke Gap' BODY699_RING1_1 = (133405.0 133730.0 0.0 0.0 0.0) BODY699_RING2_NAME = 'Cassini Division' BODY699_RING2 = (117580.0 122170.0 0.0 0.0 0.0) BODY699_RING3_NAME = 'B Ring' BODY699_RING3 = (92000.0 117580.0 0.1 0.1 1.5) BODY699_RING4_NAME = 'C Ring' BODY699_RING4 = (74510.0 92000.0 0.1 0.1 0.1) BODY699_RING5_NAME = 'D Ring' BODY699_RING5 = (66970.0 74510.0 0.1 0.1 0.00001) BODY699_RING6_NAME = 'E ring' BODY699_RING6_A = (189870.0 256900.0 9000.0 9000.0 0.000003) BODY699_RING6_B = (256900.0 420000.0 9000.0 17000.0 0.000003) BODY699_RING7_NAME = 'F Ring' BODY699_RING7 = (140180.0 140270.0 6.5 6.5 0.1) BODY699_RING7_FCENTER = (140223.7, 0.00254, 24.1, 2.7001, 0.0065, 16.1, -2.6876) BODY699_RING8_NAME = 'G Ring' BODY699_RING8 = (165000.0 176000.0 280.0 280.0 0.000001) BODY699_MIMI_DUST_ZONE = ( 0.0 527284.2 60000.0 60000.0 ) \begintext -------- URANUS \begindata BODY799_RADII = ( 25559. 25559. 24973. ) BODY799_POLE_RA = ( 257.311 0. 0. ) BODY799_POLE_DEC = ( -15.175 0. 0. ) BODY799_PM = ( 203.81 -501.1600928 0. ) BODY799_LONG_AXIS = ( 0. ) \begintext -------- MOON \begindata BODY301_RADII = ( 1737.4 1737.4 1737.4 ) BODY301_POLE_RA = ( 269.9949 0.0031 0. ) BODY301_POLE_DEC = ( 66.5392 0.0130 0. ) BODY301_PM = ( 38.3213 13.17635815 -1.4D-12 ) BODY301_LONG_AXIS = ( 0. ) BODY301_NUT_PREC_RA = ( -3.8787 -0.1204 +0.0700 -0.0172 0. +0.0072 0. 0. 0. -0.0052 0. 0. +0.0043 ) BODY301_NUT_PREC_DEC = ( 1.5419 0.0239 -0.0278 +0.0068 0. -0.0029 +0.0009 0. 0. +0.0008 0. 0. -0.0009 ) BODY301_NUT_PREC_PM = ( 3.5610 +0.1208 -0.0642 +0.0158 +0.0252 -0.0066 -0.0047 -0.0046 +0.0028 +0.0052 +0.0040 +0.0019 -0.0044 ) \begintext Satellites of Jupiter ------------------------------------------------------- -------- IO BODY501_GM value from [5]. \begindata BODY501_GM = ( 5959.916 ) BODY501_RADII = ( 1829.4 1819.3 1815.7 ) BODY501_POLE_RA = ( 268.05 -0.009 0. ) BODY501_POLE_DEC = ( +64.50 +0.003 0. ) BODY501_PM = ( 200.39 +203.4889538 0. ) BODY501_LONG_AXIS = ( 0. ) 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 ) \begintext -------- EUROPA BODY502_GM value from [5]. \begindata BODY502_GM = ( 3202.739 ) BODY502_RADII = ( 1564.13 1561.23 1560.93 ) BODY502_POLE_RA = ( 268.08 -0.009 0. ) BODY502_POLE_DEC = ( +64.51 +0.003 0. ) BODY502_PM = ( 36.022 +101.3747235 0. ) BODY502_LONG_AXIS = ( 0. ) BODY502_NUT_PREC_RA = ( 0. 0. 0. +1.086 +0.060 +0.015 +0.009 ) BODY502_NUT_PREC_DEC = ( 0. 0. 0. +0.468 +0.026 +0.007 +0.002 ) BODY502_NUT_PREC_PM = ( 0. 0. 0. -0.980 -0.054 -0.014 -0.008 ) \begintext -------- GANYMEDE BODY503_GM value from [5]. \begindata BODY503_GM = ( 9887.834 ) BODY503_RADII = ( 2632.4 2632.29 2632.35 ) BODY503_POLE_RA = ( 268.20 -0.009 0. ) BODY503_POLE_DEC = ( +64.57 +0.003 0. ) BODY503_PM = ( 44.064 +50.3176081 0. ) BODY503_LONG_AXIS = ( 0. ) BODY503_NUT_PREC_RA = ( 0. 0. 0. -0.037 +0.431 +0.091 ) BODY503_NUT_PREC_DEC = ( 0. 0. 0. -0.016 +0.186 +0.039 ) BODY503_NUT_PREC_PM = ( 0. 0. 0. +0.033 -0.389 -0.082 ) \begintext -------- CALLISTO BODY504_GM value from [5]. \begindata BODY504_GM = ( 7179.289 ) BODY504_RADII = ( 2409.4 2409.2 2409.3 ) BODY504_POLE_RA = ( 268.72 -0.009 0. ) BODY504_POLE_DEC = ( +64.83 +0.003 0. ) BODY504_PM = ( 259.51 +21.5710715 0. ) BODY504_LONG_AXIS = ( 0. ) BODY504_NUT_PREC_RA = ( 0. 0. 0. 0. -0.068 +0.590 0. +0.010 ) BODY504_NUT_PREC_DEC = ( 0. 0. 0. 0. -0.029 +0.254 0. -0.004 ) BODY504_NUT_PREC_PM = ( 0. 0. 0. 0. +0.061 -0.533 0. -0.009 ) \begintext -------- HIMALIA BODY506_GM values from [21]. \begindata BODY506_GM = ( 0.45 ) BODY506_RADII = ( 85 85 85 ) BODY506_POLE_RA = ( 268.72 -0.009 0. ) BODY506_POLE_DEC = ( +64.83 +0.003 0. ) BODY506_PM = ( 259.51 +21.5710715 0. ) BODY506_LONG_AXIS = ( 0. ) \begintext Satellites of Saturn ----------------------------------------------------------- -------- MIMAS \begindata BODY601_RADII = ( 209.1 196.2 191.4 ) BODY601_POLE_RA = ( 40.66 -0.036 0. ) BODY601_POLE_DEC = ( +83.52 -0.004 0. ) BODY601_PM = ( 337.46 +381.9945550 0. ) BODY601_LONG_AXIS = ( 0. ) BODY601_NUT_PREC_RA = ( 0. 0. +13.56 0. 0. 0. 0. 0. 0. ) BODY601_NUT_PREC_DEC = ( 0. 0. -1.53 0. 0. 0. 0. 0. 0. ) BODY601_NUT_PREC_PM = ( 0. 0. -13.48 0. -44.85 0. 0. 0. 0. ) \begintext -------- ENCELADUS \begindata BODY602_RADII = ( 256.3 247.3 244.6 ) BODY602_POLE_RA = ( 40.66 -0.036 0. ) BODY602_POLE_DEC = ( +83.52 -0.004 0. ) BODY602_PM = ( 2.82 +262.7318996 0. ) BODY602_LONG_AXIS = ( 0. ) \begintext -------- TETHYS \begindata BODY603_RADII = ( 535.6 528.2 525.8 ) BODY603_POLE_RA = ( 40.66 -0.036 0. ) BODY603_POLE_DEC = ( +83.52 -0.004 0. ) BODY603_PM = ( 10.45 +190.6979085 0. ) BODY603_LONG_AXIS = ( 0. ) BODY603_NUT_PREC_RA = ( 0. 0. 0. +9.66 0. 0. 0. 0. 0. ) BODY603_NUT_PREC_DEC = ( 0. 0. 0. -1.09 0. 0. 0. 0. 0. ) BODY603_NUT_PREC_PM = ( 0. 0. 0. -9.60 +2.23 0. 0. 0. 0. ) \begintext -------- DIONE \begindata BODY604_RADII = ( 560. 560. 560. ) BODY604_POLE_RA = ( 40.66 -0.036 0. ) BODY604_POLE_DEC = ( +83.52 -0.004 0. ) BODY604_PM = ( 357.00 +131.5349316 0. ) BODY604_LONG_AXIS = ( 0. ) \begintext -------- RHEA \begindata BODY605_RADII = ( 764. 764. 764. ) BODY605_POLE_RA = ( 40.38 -0.036 0. ) BODY605_POLE_DEC = ( +83.55 -0.004 0. ) BODY605_PM = ( 235.16 +79.6900478 0. ) BODY605_LONG_AXIS = ( 0. ) BODY605_NUT_PREC_RA = ( 0. 0. 0. 0. 0. +3.10 0. 0. 0. ) BODY605_NUT_PREC_DEC = ( 0. 0. 0. 0. 0. -0.35 0. 0. 0. ) BODY605_NUT_PREC_PM = ( 0. 0. 0. 0. 0. -3.08 0. 0. 0. ) \begintext -------- TITAN \begindata BODY606_RADII = ( 2575. 2575. 2575. ) BODY606_POLE_RA = ( 36.41 -0.036 0. ) BODY606_POLE_DEC = ( +83.94 -0.004 0. ) BODY606_PM = ( 189.64 +22.5769768 0. ) BODY606_LONG_AXIS = ( 0. ) BODY606_NUT_PREC_RA = ( 0. 0. 0. 0. 0. 0. +2.66 0. 0. ) BODY606_NUT_PREC_DEC = ( 0. 0. 0. 0. 0. 0. -0.30 0. 0. ) BODY606_NUT_PREC_PM = ( 0. 0. 0. 0. 0. 0. -2.64 0. 0. ) BODY606_ATMOSPHERE = ( 175.0 10.0 0.000006350 11400.0 76.0 0.000000513 8030.0 -429.0 0.000073500 15000.0 44.0 ) \begintext -------- HYPERION While Hyperion's spin state is chaotic, Voyager and ground-based observations suggest some states are common (Thomas et al 1995, Icarus 117, 128-148). The spin pole orientation is from the Voyager observations; both the spin pole orientation and spin rate will probably differ during Cassini's mission. Hyperion radii and orientation from Peter Thomas @ Cornell \begindata BODY607_RADII = ( 164. 130. 107. ) BODY607_POLE_RA = ( 226. 0 0 ) BODY607_POLE_DEC = ( 35. 0 0 ) BODY607_PM = ( 20.02 72.0 0 ) BODY607_LONG_AXIS = ( 0. ) \begintext -------- IAPETUS \begindata BODY608_RADII = ( 718. 718. 718. ) BODY608_POLE_RA = ( 318.16 -3.949 0. ) BODY608_POLE_DEC = ( +75.03 -1.143 0. ) BODY608_PM = ( 350.20 +4.5379572 0. ) BODY608_LONG_AXIS = ( 0. ) \begintext -------- PHOEBE BODY609_PM from [13]. \begindata BODY609_RADII = ( 115. 110. 105. ) BODY609_POLE_RA = ( 355.00 0. 0. ) BODY609_POLE_DEC = ( +68.70 0. 0. ) BODY609_PM = ( 178.58 +931.639 0. ) BODY609_LONG_AXIS = ( 0. ) \begintext -------- CONSTANTS AND NOTES FOR PDT USERS The astronomical unit AU, given in kilometers. \begindata AU = ( 149597870.7 ) \begintext Saturn reference radius (Rs) is the base for measuring body distances and ring radial distances in mulitples of saturn radius. \begindata RS = ( 60330.0 ) \begintext Note that GM values >= 1.0 are packaged as is into 7CONIC_VEC commands for AACS to propagate the body's ephemeris. For GM values < 1.0, the value in the G_MASS parameter of the 7CONIC_VEC command is set to 1.0. One is the minimum value for the G_MASS parameter. The resetting of the G_MASS parameter to the minimum acceptable where the actual GM is < 1.0 is acceptable since CAS will not pass close enough to any of the affected bodies for the gravitational mass to have an effect. -------- OBLATE SPHEROIDS VERSUS TRIAXIAL ELLIPSOIDS Some Cassini software cannot model triaxial ellipsoids, where the RADII are all different. Instead, they model bodies as oblate spheroids, where the equatorial RADII values (the first two) must be identical. In cases here where the equatorial radii are not identical, the average of the two should be used when constructing an oblate spheroid. The polar radius (the third RADII) can be used as given in both cases. -------- CONSTANTS AND NOTES FOR CASPER USERS \begindata BODY601_GM/PRIMARY = ( 6.59087D-08 ) BODY602_GM/PRIMARY = ( 1.29181D-07 ) BODY603_GM/PRIMARY = ( 1.1022D-06 ) BODY604_GM/PRIMARY = ( 1.92865D-06 ) BODY605_GM/PRIMARY = ( 4.05998D-06 ) BODY606_GM/PRIMARY = ( 2.36697D-04 ) BODY607_GM/PRIMARY = ( 2.60998D-08 ) BODY608_GM/PRIMARY = ( 2.79453D-06 ) BODY609_GM/PRIMARY = ( 1.26545D-08 ) BODY610_GM/PRIMARY = ( 3.38507D-09 ) BODY611_GM/PRIMARY = ( 9.41176D-10 ) BODY612_GM/PRIMARY = ( 4.48179D-11 ) BODY613_GM/PRIMARY = ( 1.26545D-11 ) BODY614_GM/PRIMARY = ( 6.32723D-12 ) BODY615_GM/PRIMARY = ( 1.89817D-11 ) BODY616_GM/PRIMARY = ( 5.79996D-10 ) BODY617_GM/PRIMARY = ( 3.42725D-10 ) BODY618_GM/PRIMARY = ( 4.74543D-12 ) \begintext -------- URLS AND CONTACTS Description of PCK format and contents can be found in NAIF's PCK "required reading" document, at: ftp://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/ascii/individual_docs/pck.req NAIF tutorial on PCK formatting and use at: ftp://naif.jpl.nasa.gov/pub/naif/toolkit_docs/Tutorials/office/individual_docs/16_pck.ppt ftp://naif.jpl.nasa.gov/pub/naif/toolkit_docs/Tutorials/office/packages/ SPICE_Tutorials_Office.zip The Cassini PCK & ephemeris files can be found on the DOM, and at: ftp://naif.jpl.nasa.gov/pub/naif/CASSINI/kernels/ Questions regarding this file can be directed to: Diane Conner (818)354-8586 Diane.Conner@jpl.nasa.gov Adrian Tinio (818)354-7511 Adrian.Tinio@jpl.nasa.gov David Seal (818)354-2707 David.Seal@jpl.nasa.gov -------- VERSION HISTORY The noted versions were officially published; the others were created and circulated for internal review only. 2004 Dec 09 (published) D. Conner This file was created from file cpck14Oct2004.tpc. It contains keywords that will be maintained by the PSG. NAVT maintained keywords have been moved in a separate file. Minor satellites and rocks keywords have been moved to the rocks PCK. 2004 Oct 14 (published) Documentation was added to clarify the different radii defined for Saturn. Additional references that are publicly available were added for Saturn's rings model. Jupiter's nutation precession angles, and Ganymede's W0 value were corrected to agree with the IAU 2000 report. 2004 Jun 21 (published) * Reference for new Phoebe GM: IOM 312.0-024-04 "Navigation Results from the Phoebe flyby", J.B. Jones, 16 June 2004. 2004 Mar 05 (published) Updated descriptive text preceeding RS keyword. Updated contact information and verified URLs. Updates per ECR 103313: Change 1: Update the values for Phoebe Prime Meridian TO: BODY609_PM = ( 178.58 +931.639 0. ) Reference: Bauer, Simonelli, Buratti, IAU Circular 8279, 1/30/2004; re-reduced by Owen 2/5/2004 Change 2: Saturn Reference Radius ADD: BODY699_RADII_RS = ( 60330. 60330. 60330. ) This radius models saturn as a sphere at 100 mbar. Date: Tue, 25 Nov 2003 16:22:41 -0700 From: Carolyn Porco 2002 Oct 01 (published) Changed BODY699_RADII_OPTICAL to be consistent with recommendation of Phil Nicholson dated 24 Sep. Added notes in the version history as to which versions were published to the DOM, as opposed to the versions that were intermediate for review. -------- FORMATTING FOR SPECIAL PARAMETERS BODYNNN_GM GM in km^3/s^2 BODYNNN_RADII_OPTICAL BOYDNNN_RADII_RS BOYDNNN_RADII BODYNNN_RADII_1BAR BODY699_RADII_OPTICAL is for PDT to determine at what altitude that Saturn first starts to cast a discernible shadow. BODY699_RADII_RS models Saturn as a sphere and corresponds to a 100 mbar surface. BODY699_RADII and BODY699_RADII_1BAR correspond to a 1 bar surface. BODY699_RADII contains IAU values. BODY699_RADII_1BAR currently contains IAU values but will likely be updated during the mission. BODYNNN_ATMOSPHERE Exponential atmospheric model in the form of one set of two values To, f, followed by any number of sets of three numbers Do, K, Zo. The atmospheric density in g/cm3 can be calculated as follows: Z = height above surface (km) R = radius of body (km) T = thermospheric temperature (K) = To + f * sigma, where sigma is the number of standard deviations (conservatism) desired. If f > 0, positive sigma will result in a hotter thermosphere and higher density. H = scale height of atmosphere (km) = T * ( R + Z ) / K (K is a curve-fit parameter with units of degrees K) D = density (g/cm3) = Do * exp( - ( Z - Zo ) / H ) If there are more than one set of Do, K, Zo, sum each value to get the total atmospheric density. BODYNNN_RING* The ring identification scheme is numeric with keyword-associated names. The defnition of a ring is in a set of keywords. The BODYNNN_RING... keyword set includes 1) a required NAME keyword (BODYNNN_RING_NAME), 2) either a complete ring keyword (BODYNNN_RING) or a set of segmented ring keywords (BODYNNN_RING_), and 3) optional embedded ringlet/gap keywords (BODYNNN_RING_) with required names (BODYNNN_RING__NAME). The total number of rings (BODYNNN_RING) that can be defined is from 01 to 99. A complete ring can be segmented (BODYNNN_RING_) in upto 26 (A-Z) sub-segments. Embedded ringlets/gaps (BODYNNN_RING_) can be defined from 1 to 99. Ring geometry is defined in the form of one set of R1, R2, Z1, Z2, OD where R1 and R2 are inner and outer radii respectively of the ring (in kilometers), Z1 and Z2 are the vertical heights of the ring at R1 and R2 respectively (also in km, equal to one-half of the total thickness of the ring), and OD is the average optical depth of the ring sub-segment/gap across R1 to R2. A complex ring thickness model is pieced together by sub-segmenting Rs, Zs, & ODs; each sub-segment is uniquely numbered. BODY699_RING7_FCENTER Elliptical orbital characteristics for the F Ring: The array items (and units) are (in order): SEMIMAJOR_AXIS (km) ECCENTRICITY (degrees) LONGITUDE_PERICENTER_EPOCH (degrees) PERICENTER_PRECESSION_RATE (degrees) INCLINATION (degrees) LONGITUDE_ASCENDING_NODE_EPOCH (degrees) NODAL_REGRESSION_RATE (degrees). The epoch for the elements is J2000 (noon UTC on 1/1/2000) at the ring (i.e., with no light-time correction). Longitudes are measured in the prograde direction from the ascending node of Saturn's equatorial plane on Earth's J2000 equator. -------- REFERENCES 1. Seidelmann, P.K., Abalakin, V.K., Bursa, M., Davies, M.E., Bergh, C. de, Lieske, J.H., Oberst, J., Simon, J.L., Standish, E.M., Stooke, P., and Thomas, P.C. (2002). "Report of the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites: 2000," Celestial Mechanics and Dynamical Astronomy, v.82, Issue 1, pp. 83-111. 2. Nautical Almanac Office, United States Naval Observatory and H.M. Nautical Almanac Office, Rutherford Appleton Laboratory (2005). "The Astronomical Almanac for the Year 2002," U.S. Government Printing Office, Washington, D.C.: and The Stationary Office, London. 3. Russell, Christopher T., "Geophysical Coordinate Transformations," Cosmic Electrodynamics 2 (1971) 184-186. 4. Showalter, Mark R. "Properties of Saturn's E and G Rings from the 1995 Ring Plane Crossings", presented at Ames ring hazard workshop, 25 January 1996. 5. Jacobson, R. A. 2003b. private communication of constants used in the JUP230 ephemeris 6. Jacobson, R.A., JPL IOM 312.F-99-084, 13 Oct 1999, "Sat105" ephemeris file 7. Jacobson, R. A., 1996, "Orbits of the Saturnian Satellites from Earthbased and Voyager Observations", Blulletin of the American Astronmical Society 28(3), 1185. 8. Bosh A.S., Olkin C.B., French R.G., Nicholson P.D. Icarus, May 2002, vol. 157, iss. 1, pp. 57-75(19) 9. Campbell, J.K., and J.D. Anderson, Gravity Field of the Saturnian System From Pioneer and Voyager Tracking Data, Astronomical Journal, 97, 1485-1495, 1989. 10. Cassini NAV OD solution SM828D. 11. Cassini Mission Plan, JPL D-5564, Cassini document 699-100, revision N, May 2002. 12. Cassini Dust Protection Plan, JPL D-24251, Cassini document 699-525, revision A, October 2002. 13. Bauer, Simonelli, Buratti, IAU Circular 8279, 1/30/2004; re-reduced by Owen 2/5/2004 14. Cassini NAV OD solution 040409_00Sa. 15. Cassini NAV OD solution 040615_00Sa. 16. IOM 312.0-024-04 "Navigation Results from the Phoebe flyby", J.B. Jones, 16 June 2004. 17. Cassini NAV OD solution 040909R. Reconstruction from Jupiter to SOI. 19. Cuzzi, J. N., J. J. Lissauer, L. W. Esposito, J. B. Holberg, E. A. Marouf, G. L. Tyler, and A. Bouschot 1984. "Saturn's rings: Properties and processes." In Planetary Rings, (R. Greenberg and A. Brahic, Eds.), University of Arizona Press, Tucson, pp. 73-199. 20. HST High-Resolution Backscatter Image of Saturn's G Ring Jack J. Lissauer, Richard G. French Icarus, Vol. 146, No. 1, Jul 2000, pp. 12-18. 21. NASA/JPL Web page: "Natural Satellite Physical Parameters", 2004 September 22 Unless noted otherwise, values are from the IAU report. [1]