USGS

ISIS 2 Documentation


Isis NAIF SPICE Kernels

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NAIF SPICE KERNELS IN THE ISIS SYSTEM Mars Global Surveyor MOC Instrument Created: May 22, 2000 Updated: July 14, 2006

This document describes NAIF SPICE kernels in ISIS and how to find, retrieve, format, convert and install NAIF SPICE kernels for the Mars Orbital Camera (MOC) instrument on the Mars Global Surveyor (MGS) spacecraft.

This document does not attempt to explain in any great detail NAIF SPICE kernels except when needed to describe content and usage. NAIF has done an excellent job documenting their product.

  1. ALL ABOUT NAIF
  2. USE OF SPICE IN ISIS
  3. ACQUIRING YOUR OWN MOC SPICE KERNELS
  4. CONCLUSION

1. ALL ABOUT NAIF

NAIF, Navigation Ancillary Information Facility, provides ancillary information for space-bourne instruments. See http://naif.jpl.nasa.gov/naif.html for more information on NAIF.

1.1 THE NAIF TOOLKIT

NAIF has produced an extensive toolkit to manipulate SPICE kernels. It is available in ANSI FORTRAN 77 and ANSI C versions for many computer platforms. Both toolkits can be acquired through ftp from the NAIF facility. Here are the instructions for downloading the NAIF toolkits:
  cd /to_big_C_toolkit_area
ftp naif.jpl.nasa.gov
binary
prompt
cd /pub/naif/toolkit/C/[desired platform]
mget *
lcd /to_big_FORTRAN_toolkit_area
cd ../FORTRAN/[desired platform]
mget *
bye

Note that some of the files in the toolkits share the same name so they require separate directories. Under each toolkit directory, there is an "exe" directory that contains NAIF SPICE applications used to manipulate many of the kernels.

In each toolkit is a "doc" directory which contains extensive documentation of NAIF products. Interested users should consult these files for further information on SPICE kernels and toolkit information.

2. USE OF SPICE IN ISIS

ISIS uses SPICE data for many missions, one of which is MGS/MOC. SPICE data generally consists of binary and text "kernels". The binary SPICE kernel files are SP-kernels (SPK), a few PC-kernels (PCK), C-kernels (CK) and some E-kernels (EK). These binary kernels may require one to convert them to be compatable with the computer's binary format. There are utilities provided (in the "exe" toolkit directory mentioned previously) that can perform this conversion. There are also a handful of text kernels: Spacecraft Clock kernels (SCLK), Leapseconds kernel (LSK), most Physical Constants kernels (PCK), Instrument parameter kernels (IK) and some spacecraft Events kernels (EK). These kernels require no conversion and can be used on all computers.

ISIS also uses both the FORTRAN and C SPICE NAIF programming toolkits to access NAIF SPICE kernels. The MGS/MOC software almost entirely uses the C toolkit.

2.1 GENERIC KERNELS

The following is a list of kernel files followed by a brief description of generic SPICE kernels used in ISIS:

$ISISMGSDATA/naif0008.tls - Leapseconds kernel (LSK). This file is required to perform conversion of time from one representation to another. This is a text based kernel. These kernels change infrequently.

$ISISMGSDATA/pck00006.tpc - Planetary constants kernel (PCK). This file contains data used to model the orientation and shape of the Sun, planets, and satellites. This is a text based kernel and also changes infrequently.

$ISISDATA/de405.bsp - Planetary Ephemerides kernel (SPK). This file contains information that model the sun, planets and satellites relative positions. This is a binary kernel. This kernel changes infrequently.

2.2 MGS/MOC MISSION SPECIFIC KERNELS

For each mission, ISIS acquires a set of NAIF SPICE kernels and maintains them for, at least, the life of the mission. Many are supported long after the data acquisition phase of a mission is completed. These kernels can change quite frequently and may require a great deal of resources to maintain and house them. MOC is one of these missions. To date, MOC kernels in ISIS require around 2.3GB of disk space to install all of them on disk. New CK and SPK kernels are available daily. MGS is currently in Extended phases of the original mission.

Most all NAIF SPICE kernels have an accompanying text file or label, that ends with ".lbl" appended to the kernel file name. We highly recommend users review these files as they contain very important and detailed information concerning the kernel.

Some SPICE kernels have an additional text file with a ".log" extention. These files are generated by USGS personnel using the NAIF "spacit" utility that summerizes the dates of coverage of the file. This will typically apply only to the volatile daily SPK and CK kernels.

The following is list of kernels that are in use and are anticipated for the MGS/MOC mission in the ISIS system. All kernel files are binary kernel files unless otherwise indicated:

$ISISMGSDATA/moc13.ti - MOC Instrument kernel (IK or I-kernel). This file contains the MOC instrument mounting offsets, and both the narrow and wide angle fields of view and focal lengths. This is a text based kernel. It generally will not change much at all.

$ISISMGSDATA/MGS_SCLKSCET.00059.tsc - Spacecraft Clock kernel (SCLK). This file contains information required for MGS spacecraft on-board clock to ephemeris time (ET) conversion. It also contains definitions of MGS reference frames. Reference frames, in this context, refer to the orientation of the spacecraft subsystems with respect to the spacecraft. This file is text based. It has in the past changed pretty frequently.

SPK Kernels - These kernels are the ephemeris data for the MGS spacecraft. They consist of two aerobraking cycles (AB1 and AB2), two science phase cycles (SPO1 and SPO2), 8 mapping phases (MAP1 through MAP8) and 23 Extended Mission phases (EXT1 through EXT23). There are also CK kernels that correspond to each one of these SPK kernels. The SPICE mapping cycles should not be confused with MOC mapping cycles. This is NAIF's designation for SPICE kernel release. A NAIF SPICE MGS/MOC cycle is a 28 days and each mapping phase contains 3 cycles of these data. Below is a complete list of acquired or anticipated SPK kernels including coverage dates and current status:

$ISISMGSDATA/mgs_ab1.bsp - Acquired. This file covers Aerobraking-1 (AB1) phase of the MGS mission (orbits 2 through 199):

        COVERAGE BEGIN TIME (TDB):   1997 SEP 12 01:40:55.000
        COVERAGE END TIME (TDB):     1998 MAR 26 05:25:00.000

The file coverage begins 40 minutes after MOI burn which started at approximately 1997 SEP 12 01:17 TDB.

$ISISMGSDATA/mgs_ab2.bsp - Acquired. This file covers Aerobraking-2 (AB2) phase of the MGS mission (orbits 573 through 1683):

        COVERAGE BEGIN TIME (TDB):   1998 SEP 23 02:25:00.000
        COVERAGE END TIME (TDB):     1999 MAR 09 01:00:00.000

$ISISMGSDATA/mgs_spo1.bsp - Acquired. This file covers Science Phasing Orbit 1 (SPO-1) phase of the MGS mission (orbits 200 through 328):

        COVERAGE BEGIN TIME (TDB):   1998 MAR 25 17:15:00.000
        COVERAGE END TIME (TDB):     1998 MAY 28 00:00:00.000

$ISISMGSDATA/mgs_spo2.bsp - Acquired. This file covers Science Phasing Orbit 2 (SPO-2) phase of the MGS mission (orbits 329 through 572):

        COVERAGE BEGIN TIME (TDB):   1998 MAY 27 23:00:00.000
        COVERAGE END TIME (TDB):     1998 SEP 23 02:30:00.000

$ISISMGSDATA/mgs_map1.bsp - Acquired. This file covers first three 28-day mapping cycles of the Mapping phase of the mission (mapping orbits 1 through 1040):

        COVERAGE BEGIN TIME (TDB):   1999 MAR 09 01:00:00.000
        COVERAGE END TIME (TDB):     1999 JUN 02 01:00:00.000

$ISISMGSDATA/mgs_map2.bsp - Acquired. This file covers 4th, 5th and 6th 28-day mapping cycles of the Mapping phase of the mission (mapping orbits 1040 through 2068):

        COVERAGE BEGIN TIME (TDB):   1999 JUN 02 00:00:00.000
        COVERAGE END TIME (TDB):     1999 AUG 25 01:00:00.000

$ISISMGSDATA/mgs_map3.bsp - Acquired. This file covers 7th, 8th and 9th 28-day mapping cycles of the Mapping phase of the mission (mapping orbits 2069 through 3096):

        COVERAGE BEGIN TIME (TDB):   1999 AUG 25 00:00:00.000
        COVERAGE END TIME (TDB):     1999 NOV 17 01:00:00.000

$ISISMGSDATA/mgs_map4.bsp - Acquired. This file covers 10th, 11th and 12th 28-day mapping cycles of the Mapping phase of the mission (mapping orbits 3097 through 4125):

        COVERAGE BEGIN TIME (TDB):   1999 NOV 17 00:00:00.000
        COVERAGE END TIME (TDB):     2000 FEB 09 01:00:00.000

$ISISMGSDATA/mgs_map5.bsp - Acquired. This file covers 13th, 14th and 15th 28-day mapping cycles of the Mapping phase of the mission (mapping orbits 4125 through 5152):

        COVERAGE BEGIN TIME (TDB):   2000 FEB 09 00:00:00.000
        COVERAGE END TIME (TDB):     2000 MAY 03 01:00:00.000

$ISISMGSDATA/mgs_map6.bsp - Acquired. This file covers 16th, 17th and 18th 28-day mapping cycles of the Mapping phase of the mission (mapping orbits 5153 through 6181):

        COVERAGE BEGIN TIME (TDB):   2000 MAY 03 00:00:00.000
        COVERAGE END TIME (TDB):     2000 JUL 26 01:00:00.000

$ISISMGSDATA/mgs_map7.bsp - Acquired. This file covers 19th, 20th and 21th 28-day mapping cycles of the Mapping phase of the mission (mapping orbits 6181 through 7209):

        COVERAGE BEGIN TIME (TDB):   2000 JUL 26 00:00:00.000
        COVERAGE END TIME (TDB):     2000 OCT 18 01:00:00.000

$ISISMGSDATA/mgs_map8.bsp - Acquired. This file covers 22nd, 23rd, 24th and a part of 25th -- through the end of the mapping phase -- 28-day mapping cycles of the Mapping phase of the mission (mapping orbits 7209 through 8505):

        COVERAGE BEGIN TIME (TDB):   2000 OCT 18 00:00:00.000
        COVERAGE END TIME (TDB):     2001 FEB 01 01:00:00.000

$ISISMGSDATA/mgs_ext1.bsp - Acquired. This file covers a part of 25th -- from the beginning of the Extended mission, -- whole 26th and 27th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 8506 through 9264):

        COVERAGE BEGIN TIME (TDB):   2001 FEB 01 00:00:00.000
        COVERAGE END TIME (TDB):     2001 APR 04 01:00:00.000

$ISISMGSDATA/mgs_ext2.bsp - Acquired. This file covers the 28th, 29th and 30th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 9264 through 10291):

        COVERAGE BEGIN TIME (TDB):   2001 APR 04 00:00:00.000
        COVERAGE END TIME (TDB):     2001 JUN 27 01:00:00.000

$ISISMGSDATA/mgs_ext3.bsp - Acquired. This file covers the 31st, 32nd, and 33rd 28-day mapping cycles of the Extended phase of the mission (mapping orbits 10291 through 11318):

        COVERAGE BEGIN TIME (TDB):   2001 JUN 27 00:00:00.000
        COVERAGE END TIME (TDB):     2001 SEP 19 01:00:00.000

$ISISMGSDATA/mgs_ext4.bsp - Acquired. This file covers the 34th, 35th, and 36th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 11319 through 12345):

        COVERAGE BEGIN TIME (TDB):   2001 SEP 19 00:00:00.000
        COVERAGE END TIME (TDB):     2001 DEC 12 01:00:00.000

$ISISMGSDATA/mgs_ext5.bsp - Acquired. This file covers the 37th, 38th, and 39th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 12346 through 13373):

        COVERAGE BEGIN TIME (TDB):   2001 DEC 12 00:00:00.000
        COVERAGE END TIME (TDB):     2002 MAR 06 01:00:00.000

$ISISMGSDATA/mgs_ext6.bsp - Acquired. This file covers the 40th, 41st, and 42nd 28-day mapping cycles of the Extended phase of the mission (mapping orbits 13374 through 14400):

        COVERAGE BEGIN TIME (TDB):   2002 MAR 06 00:00:00.000
        COVERAGE END TIME (TDB):     2002 MAY 29 01:00:00.000

$ISISMGSDATA/mgs_ext7.bsp - Acquired. This file covers the 43rd, 44th, and 45th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 14401 through 15428):

        COVERAGE BEGIN TIME (TDB):   2002 MAY 29 00:00:00.000
        COVERAGE END TIME (TDB):     2002 AUG 21 01:00:00.000

$ISISMGSDATA/mgs_ext8.bsp - Acquired. This file covers the 46th, 47th, and 48th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 15429 through 16455):

        COVERAGE BEGIN TIME (TDB):   2002 AUG 21 00:00:00.000
        COVERAGE END TIME (TDB):     2002 NOV 13 01:00:00.000

$ISISMGSDATA/mgs_ext9.bsp - Acquired. This file covers the 49th, 50th, and 51rst 28-day mapping cycles of the Extended phase of the mission (mapping orbits 16456 through 17483):

        COVERAGE BEGIN TIME (TDB):   2002 NOV 13 00:00:00.000
        COVERAGE END TIME (TDB):     2003 FEB 05 01:00:00.000

$ISISMGSDATA/mgs_ext10.bsp - Acquired. This file covers the 52nd, 53rd, and 54th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 17483 through 18511):

        COVERAGE BEGIN TIME (TDB):   2003 FEB 05 00:00:00.000
        COVERAGE END TIME (TDB):     2003 APR 30 01:00:00.000

$ISISMGSDATA/mgs_ext11.bsp - Acquired. This file covers the 55th, 56th, and 57th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 18511 through 19538):

        COVERAGE BEGIN TIME (TDB):   2003 APR 30 00:00:00.000
        COVERAGE END TIME (TDB):     2003 JUL 23 01:00:00.000

$ISISMGSDATA/mgs_ext12.bsp - Acquired. This file covers the 58th, 59th, and 60th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 19539 through 20566):

        COVERAGE BEGIN TIME (TDB):   2003 JUL 23 00:00:00.000
        COVERAGE END TIME (TDB):     2003 OCT 15 01:00:00.000

$ISISMGSDATA/mgs_ext13.bsp - Acquired. This file covers the 61th, 62th, and 63th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 20567 through 21593):

        COVERAGE BEGIN TIME (TDB):   2003 OCT 15 00:00:00.000
        COVERAGE END TIME (TDB):     2004 JAN 07 01:00:00.000

$ISISMGSDATA/mgs_ext14.bsp - Acquired. This file covers the 64th, 65th, and 66th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 21594 through 22621):

        COVERAGE BEGIN TIME (TDB):   2004 JAN 07 00:00:00.000
        COVERAGE END TIME (TDB):     2004 MAR 31 01:00:00.000

$ISISMGSDATA/mgs_ext15.bsp - Acquired. This file covers the 67th, 68th, and 69th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 22622 through 23648):

        COVERAGE BEGIN TIME (TDB):   2004 MAR 31 00:00:00.000
        COVERAGE END TIME (TDB):     2004 JUN 23 01:00:00.000

$ISISMGSDATA/mgs_ext16.bsp - Acquired. This file covers the 70th, 71rst, and 72nd 28-day mapping cycles of the Extended phase of the mission (mapping orbits 23649 through 24675):

        COVERAGE BEGIN TIME (TDB):   2004 JUN 23 01:00:00.000
        COVERAGE END TIME (TDB):     2004 SEP 15 01:00:00.000

$ISISMGSDATA/mgs_ext17.bsp - Acquired. This file covers the 73rd, 74th, and 75th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 24676 through 25702):

        COVERAGE BEGIN TIME (TDB):   2004 SEP 15 00:00:00.000
        COVERAGE END TIME (TDB):     2004 DEC 08 01:00:00.000

$ISISMGSDATA/mgs_ext18.bsp - Acquired. This file covers the 76th, 77th, and 78th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 25703 through 26729):

        COVERAGE BEGIN TIME (TDB):   2004 DEC 08 00:00:00.000
        COVERAGE END TIME (TDB):     2005 MAR 02 01:00:00.000

$ISISMGSDATA/mgs_ext19.bsp - Acquired. This file covers the 79th, 80th, and 81rst 28-day mapping cycles of the Extended phase of the mission (mapping orbits 25730 through 27757):

        COVERAGE BEGIN TIME (TDB):   2005 MAR 02 00:00:00.000
        COVERAGE END TIME (TDB):     2005 MAY 25 01:00:00.000

$ISISMGSDATA/mgs_ext20.bsp - Acquired. This file covers the 82nd, 83rd, and 84th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 27758 through 28784):

        COVERAGE BEGIN TIME (TDB):   2005 MAY 25 00:00:00.000
        COVERAGE END TIME (TDB):     2005 AUG 17 01:00:00.000

$ISISMGSDATA/mgs_ext21.bsp - Acquired. This file covers the 85th, 86th, and 87th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 28785 through 29811):

        COVERAGE BEGIN TIME (TDB):   2005 AUG 17 00:00:00.000
        COVERAGE END TIME (TDB):     2005 NOV 09 01:00:00.000

$ISISMGSDATA/mgs_ext22.bsp - Acquired. This file covers the 88th, 89th, and 90th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 29812 through 30839):

        COVERAGE BEGIN TIME (TDB):   2005 NOV 09 00:00:00.000
        COVERAGE END TIME (TDB):     2006 FEB 01 01:00:00.000

$ISISMGSDATA/mgs_ext23.bsp - Acquired. This file covers the 91rst, 92nd, and 93rd 28-day mapping cycles of the Extended phase of the mission (mapping orbits (mapping orbits 30840 through 31866):

        COVERAGE BEGIN TIME (TDB):   2006 FEB 01 00:00:00.000
        COVERAGE END TIME (TDB):     2006 APR 26 01:00:00.000

$ISISMGSDATA/mgs_map_rec.bsp - Acquired. This is the daily SPK file that is continually updated by NAIF with spacecraft ephemeris data. Each day data is appended to this file when received and processed by NAIF.

        COVERAGE BEGIN TIME (UTC):   2006 APR 25 23:58:54.814
        COVERAGE END TIME (UTC):     2006 JUL 09 14:13:54.816

*$ISISMGSDATA/mgs_map.bsp - *NOTE: This file is included in ISISMGSDATA, however it is recommended that you use mgs_map_rec.bsp* - An updated MGS mission MOC kernel. Coverage times are:

        COVERAGE BEGIN TIME (UTC):   2006 APR 25 23:58:54.814
        COVERAGE END TIME (UTC):     2006 AUG 02 23:58:54.817

CK Kernels - These kernels are the complete set of MGS spacecraft orientation and angular velocity data relative to the 'J2000' inertial frame. Like the SPK kernels, they too consist of two aerobraking cycles (AB1 and AB2), two science phase cycles (SPO1 and SPO2), 8 mapping phases (MAP1 through MAP8) and 23 Extended Mission phases (EXT1 through EXT23). These files correspond directly with their SPK counterparts in time coverage. The SPICE mapping cycles should not be confused with MOC mapping cycles. This is NAIF's designation for SPICE kernel release. A NAIF SPICE MGS/MOC cycle is generally 28 days and each mapping phase contains 3 cycles of these data. Below is a complete list of acquired and anticipated CK kernels including converage dates and current status:

$ISISMGSDATA/mgs_sc_ab1.bc - Acquired. This file covers the whole Aerobraking-1 phase of the mission:

        COVERAGE BEGIN TIME (UTC):   1997-09-13T00:00:00.355
        COVERAGE END TIME (UTC):     1998-03-25T23:59:56.070

$ISISMGSDATA/mgs_sc_ab2.bc - Acquired. This file covers the whole aerobraking-2 phase of the mission:

        COVERAGE BEGIN TIME (UTC):   1998-09-23T00:26:15.661
        COVERAGE END TIME (UTC):     1999-03-08T21:16:08.042

$ISISMGSDATA/mgs_sc_spo1.bc - Acquired. This file covers the whole SPO-1 phase of the mission:

        COVERAGE BEGIN TIME (UTC):   1998-03-26T00:00:00.070
        COVERAGE END TIME (UTC):     1998-05-27T23:59:55.574

$ISISMGSDATA/mgs_sc_spo2.bc - Acquired. This file covers the whole SPO-2 phase of the mission:

        COVERAGE BEGIN TIME (UTC):   1998-05-28T00:00:03.574
        COVERAGE END TIME (UTC):     1998-09-22T23:06:30.662

$ISISMGSDATA/mgs_sc_map1.bc - Acquired. This file covers first three 28-day mapping cycles of the Mapping phase of the mission:

        COVERAGE BEGIN TIME (UTC):   1999-MAR-09 00:04:32.038
        COVERAGE END TIME (UTC):     1999-JUN-01 23:59:54.058

$ISISMGSDATA/mgs_sc_map2.bc - Acquired. This file covers fourth, fifth and sixth mapping cycles of the Mapping phase of the mission:

        COVERAGE BEGIN TIME (UTC):   1999-JUN-02 00:00:02.058
        COVERAGE END TIME (UTC):     1999-AUG-24 23:59:53.237

$ISISMGSDATA/mgs_sc_map3.bc - Acquired. This file covers 7th, 8th and 9th mapping cycles of the Mapping phase of the mission:

        COVERAGE BEGIN TIME (UTC):   1999-AUG-25 00:00:05.232
        COVERAGE END TIME (UTC):     1999-NOV-16 23:59:56.360

$ISISMGSDATA/mgs_sc_map4.bc - Acquired. This file covers 10th, 11th and 12th mapping cycles of the Mapping phase of the mission:

        COVERAGE BEGIN TIME (UTC):   1999-NOV-17 00:00:04.360
        COVERAGE END TIME (UTC):     2000-FEB-08 23:59:55.476

$ISISMGSDATA/mgs_sc_map5.bc - Acquired. This file covers 13th, 14th and 15th mapping cycles of the Mapping phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2000-FEB-09 00:00:03.477
        COVERAGE END TIME (UTC):     2000-MAY-02 23:59:54.555

$ISISMGSDATA/mgs_sc_map6.bc - Acquired. This file covers 16th, 17th and 18th mapping cycles of the Mapping phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2000-MAY-03 00:00:58.554
        COVERAGE END TIME (UTC):     2000-JUL-25 23:59:53.600

$ISISMGSDATA/mgs_sc_map7.bc - Acquired. This file covers 19th, 20th and 21st mapping cycles of the Mapping phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2000-JUL-26 00:01:01.600
        COVERAGE END TIME (UTC):     2000-OCT-17 23:59:56.623

$ISISMGSDATA/mgs_sc_map8.bc - Acquired. This file covers 22nd, 23rd, 24th and a half of 25th -- through the end of the Mapping mission -- mapping cycles of the Mapping phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2000-OCT-18 00:01:00.622
        COVERAGE END TIME (UTC):     2001-JAN-31 23:59:55.365

$ISISMGSDATA/mgs_sc_ext1.bc - Acquired. This file covers a half of 25th -- from the beginning of Extended Mission, -- whole 26th and 27th mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2001-FEB-01 00:00:59.362
        COVERAGE END TIME (UTC):     2001-APR-03 23:59:54.612

$ISISMGSDATA/mgs_sc_ext2.bc - Acquired. This file covers the 28th, 29th and 30th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 9264 through 10291):

        COVERAGE BEGIN TIME (TDB):   2001 APR 04 00:00:00.000
        COVERAGE END TIME (TDB):     2001 JUN 27 01:00:00.000

$ISISMGSDATA/mgs_sc_ext3.bc - Acquired. This file covers the 31st, 32nd, and 33rd mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2001-JUN-27 00:00:05.586
        COVERAGE END TIME (UTC):     2001-SEP-18 23:59:56.546

$ISISMGSDATA/mgs_sc_ext4.bc - Acquired. This file covers the 34th, 35th, and 36th 28-day mapping cycles of the Extended phase of the mission (mapping orbits 11319 through 12345):

        COVERAGE BEGIN TIME (UTC):   2001-SEP-19 00:00:04.547
        COVERAGE END TIME (UTC):     2001-DEC-12 23:59:55.473

$ISISMGSDATA/mgs_sc_ext5.bc - Acquired. This file covers the 37th, 38th, and 39th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2001-12-12T00:00:03.485
        COVERAGE END TIME (UTC):     2002-03-05T23:33:14.401

$ISISMGSDATA/mgs_sc_ext6.bc - Acquired. This file covers the 40th, 41st, and 42nd 28-day mapping cycles of the. Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2002-MAR-06 00:07:27.400
        COVERAGE END TIME (UTC):     2002-MAY-28 23:59:53.297

$ISISMGSDATA/mgs_sc_ext7.bc - Acquired. This file covers the 43rd, 44th, and 45th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2002-MAY-29 00:01:01.297
        COVERAGE END TIME (UTC):     2002-AUG-20 22:22:08.168

$ISISMGSDATA/mgs_sc_ext8.bc - Acquired. This file covers the 46th, 47th, and 48th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2002-AUG-21 00:01:00.166
        COVERAGE END TIME (UTC):     2002-NOV-12 23:59:55.023

$ISISMGSDATA/mgs_sc_ext9.bc - Acquired. This file covers the 49th, 50th, and 51rst 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2002-NOV-13 00:00:59.022
        COVERAGE END TIME (UTC):     2003-FEB-04 23:59:53.884

$ISISMGSDATA/mgs_sc_ext10.bc - Acquired. This file covers the 52nd, 53rd, and 54th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2003-FEB-05 00:00:57.863
        COVERAGE END TIME (UTC):     2003-APR-29 23:44:44.695

$ISISMGSDATA/mgs_sc_ext11.bc - Acquired. This file covers the 55th, 56th, and 57th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2003-APR-30 00:01:00.694
        COVERAGE END TIME (UTC):     2003-JUL-22 23:59:55.525

$ISISMGSDATA/mgs_sc_ext12.bc - Acquired. This file covers the 58th, 59th, and 60th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2003-JUL-23 00:00:59.525
        COVERAGE END TIME (UTC):     2003-OCT-14 23:59:54.343

$ISISMGSDATA/mgs_sc_ext13.bc - Acquired. This file covers the 61th, 62th, and 63th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2003-OCT-15 00:00:02.343
        COVERAGE END TIME (UTC):     2004-JAN-06 23:59:53.144

$ISISMGSDATA/mgs_sc_ext14.bc - Acquired. This file covers the 64th, 65th, and 66th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2004-JAN-07 00:01:01.144
        COVERAGE END TIME (UTC):     2004-MAR-30 23:59:55.922

$ISISMGSDATA/mgs_sc_ext15.bc - Acquired. This file covers the 67th, 68th, and 69th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2004-MAR-31 00:00:59.921
        COVERAGE END TIME (UTC):     2004-JUN-22 23:59:54.683

$ISISMGSDATA/mgs_sc_ext16.bc - Acquired. This file covers the 70th, 71rst, and 72nd 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2004-JUN-23 00:00:30.681
        COVERAGE END TIME (UTC):     2004-SEP-14 16:53:05.438

$ISISMGSDATA/mgs_sc_ext17.bc - Acquired. This file covers the 73rd, 74th, and 75th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2004-SEP-15 19:13:41.420
        COVERAGE END TIME (UTC):     2004-DEC-07 23:59:56.167

$ISISMGSDATA/mgs_sc_ext18.bc - Acquired. This file covers the 76th, 77th, and 78th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2004-DEC-08 00:01:00.167
        COVERAGE END TIME (UTC):     2005-MAR-01 23:59:54.896

$ISISMGSDATA/mgs_sc_ext19.bc - Acquired. This file covers the 79TH, 80th, and 81rst 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2005-MAR-02 00:00:58.896
        COVERAGE END TIME (UTC):     2005-MAY-24 23:59:56.626

$ISISMGSDATA/mgs_sc_ext20.bc - Acquired. This file covers the 82nd, 83rd, and 84th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2005-MAY-25 00:01:00.621
        COVERAGE END TIME (UTC):     2005-AUG-16 23:59:52.847

$ISISMGSDATA/mgs_sc_ext21.bc - Acquired. This file covers the 85th, 86th, and 87th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2005-AUG-17 00:00:06.844
        COVERAGE END TIME (UTC):     2005-NOV-08 23:59:55.055

$ISISMGSDATA/mgs_sc_ext22.bc - Acquired. This file covers the 88th, 89th, and 90th 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2005-NOV-09 00:00:59.055
        COVERAGE END TIME (UTC):     2006-JAN-31 23:59:52.747

$ISISMGSDATA/mgs_sc_ext23.bc - Acquired. This file covers the 91rst, 92nd, and 93rd 28-day mapping cycles of the Extended phase of the mission:

        COVERAGE BEGIN TIME (UTC):   2006-FEB-01 00:01:00.747
        COVERAGE END TIME (UTC):     2006-APR-25 23:59:55.411

$ISISMGSDATA/mgs_sc_map.bc - NOT Acquired. Constructed from daily CK files starting the day after the last merged CK kernel NAIF delivered.

*NOTE*: THIS FILE IS NO LONGER UPDATED REGULARLY. UPDATES OCCUR BY DEMAND BY MISSION RELATED PERSONEL

Here is a complete table of MOC SPICE kernel coverage dates. Note the table gives SPK file names and will end in ".bsp". CK files will correspond to these dates but will be of the form "mgs_sc_map[1-8].bc" and "mgs_sc_ext[1-18].bc":

        SPK File   Map.    Start     Stop     Start   Stop
          Name   Cycles    Date      Date     Orbit# Orbit#
        -------- ------ ---------- ---------- ------ ------
        mgs_map1  1-3   1999-03-09 1999-06-01     1   1040
        mgs_map2  4-6   1999-06-02 1999-08-24  1041   2068
        mgs_map3  7-9   1999-08-25 1999-11-16  2069   3096
        mgs_map4 10-12  1999-11-17 2000-02-08  3097   4124
        mgs_map5 13-15  2000-02-09 2000-05-02  4125   5152
        mgs_map6 16-18  2000-05-03 2000-07-25  5153   6180
        mgs_map7 19-21  2000-07-26 2000-10-17  6181   7208
        mgs_map8 22-25* 2000-10-18 2001-01-31  7209   8505

                          (*) ``map8'' file covers
                              approximately 3.7 cycles
                              because it extends through
                              the end of mapping mission.

                          current and expected merged extended
                          SPK file coverage intervals are:

        SPK File   Map.    Start     Stop     Start   Stop
          Name   Cycles    Date      Date     Orbit# Orbit#
        -------- ------ ---------- ---------- ------ ------
        mgs_ext1 25-27* 2001-02-01 2001-04-03  8506   9264
        mgs_ext2 28-30  2001-04-04 2001-06-26  9265  10291
        mgs_ext3 31-33  2001-06-27 2001-09-18 10291  11318
        mgs_ext4 34-36  2001-09-19 2001-12-11 11319  12345
        mgs_ext5 37-39  2001-12-12 2002-03-05 12346  13373
        mgs_ext6 40-42  2002-03-06 2002-05-28 13374  14400
        mgs_ext7 43-45  2002-05-29 2002-08-21 14401  15428
        mgs_ext8 46-48  2002-08-21 2002-11-13 15429  16455
        mgs_ext9 49-51  2002-11-13 2003-02-05 16456  17483
       mgs_ext10 52-54  2003-02-05 2003-04-30 17484  18511
       mgs_ext11 55-57  2003-04-30 2003-07-23 18511  19538
       mgs_ext12 58-60  2003-07-23 2003-10-15 19539  20566
       mgs_ext13 61-63  2003-10-15 2004-01-07 20567  21593
       mgs_ext14 64-66  2004-01-07 2004-03-30 21594  22621
       mgs_ext15 67-69  2004-03-31 2004-06-23 22622  23648
       mgs_ext16 70-72  2004-06-23 2004-09-15 23649  24675
       mgs_ext17 73-75  2004-09-15 2004 12-08 23676  25702
       mgs_ext18 76-78  2004-12-08 2005 03-02 25703  26729
       mgs_ext19 79-81  2005-03-02 2005 05-25 26730  27757
       mgs_ext20 82-84  2005-05-25 2005 08-17 27758  28784
       mgs_ext21 85-87  2005-08-17 2005-11-08 28785  29811
       mgs_ext22 88-90  2005-11-09 2006-01-31 29812  30839
       mgs_ext23 91-93  2006-02-01 2006-02-01 30840  31866

                          (*) ``ext1'' file covers 2.3 cycles
                              because it starts at the
                              beginning of extended mission.

2.3 ISIS SPICE KERNEL MANAGEMENT FOR MOC

All MGS/MOC kernels are stored in a directory specified by the ISISMGSDATA environment variable. Other generic kernels are stored in a directory specified by the ISISDATA environment variable. $ISISMGSDATA stores files other than SPICE kernels but, generally, all are related to the Mars Global Surveyor mission in some way.

ISIS uses a file in $ISISMGSDATA called "moc_kernels.def.x" that contains a list of all MOC SPICE kernels. Note that "x" denotes a version number for the file that can be continually increased as new versions are added. Only the highest number is used to load NAIF kernels by ISIS applications. All ISIS applications that require SPICE data open this file and load all files specified therein. Thus, no applications need be changed...simply, this file can be updated when new SPICE is acquired. Comments in this file are indicated by a '#' character. Any characters that occur after the '#' are ignored. Blank lines are allowed, but ignored. All other contents of this file are deemed to be a SPICE kernel file. Each one that occurs is loaded (via the NAIF toolkit "furnsh" routine). Note that if the file does not exist it is ignored and not loaded. It is not an error. This allows one to include all anticipated SPICE kernels and will not require the file to be changed.

3. ACQUIRING YOUR OWN MOC SPICE KERNELS

Individuals can acquire SPICE kernels directly from NAIF's ftp site. It provides anonymous ftp access to all its kernels (and tookits). The IP address of this site is naif.jpl.nasa.gov (137.78.218.69).

MOC binary SPICE kernels are delivered in a form compatable with Sun systems. This format is not compatable with Intel Linux or Compaq Alpha Tru64 systems so they must be converted on a Sun to transfer format, moved to a Linux or Compaq system and converted to binary. Obviously, this requires access to a Sun or Sun compatable system.

MOC SPICE kernels are updated daily. Usually, there is SPICE from the day before for both SPK and CK data. MGS/MOC SPK kernels are located in /pub/naif/MGS/kernels/spk. MGS/MOC CK kernels are located in /pub/naif/MGS/kernels/ck. Other directories exist in /pub/naif/MGS/kernels that can be checked periodically for new SPICE kernels.

3.1 SPK DAILY KERNEL FILES

MGS SPK daily kernels files are "Up-to-date" mapping SPK files created by append-merging regular reconstructed OD solution SPK file from MGS NAV. Files of interest are in /pub/naif/MGS/kernels/spk. There are at least two files of interest in this directory: mgs_map.bsp and mgs_map_rec.bsp. We have been retrieving both files but are using mgs_map_rec.bsp. To do this, set your default directory to an appropriately large disk and use the following set of commands (% denotes Unix prompt, "ftp>" denotes ftp prompts, and # for comments):
  % ftp naif.jpl.nasa.gov
# Enter "anonymous" for user name and "your_name@" for password.
ftp> cd /pub/naif/MGS/kernels/spk
ftp> bin
ftp> get mgs_map.bsp
ftp> get mgs_map_rec.bsp
ftp> bye

Once these files have been transfered to your Sun or Sun compatable machine, they need to be converted to transfer format, copied to your Linux or Compaq machine and converted back to binary. The NAIF programs to do this are "toxfr" and "tobin", respectively. You can use either the FORTRAN or C toolkit versions of these applications. These commands will be done using the C version of the programs unless otherwise indicated.

On the Sun system, use the following command to convert the files to transfer format:

$CSPICE/exe/toxfr mgs_map.bsp mgs_map.bsp.xfr $CSPICE/exe/toxfr mgs_map_rec.bsp mgs_map_rec.bsp.xfr

Now copy the files to your Linux or Compaq machine and convert back to binary format:

$CSPICE/exe/tobin mgs_map.bsp.xfr mgs_map.bsp $CSPICE/exe/tobin mgs_map_rec.bsp.xfr mgs_map_rec.bsp

3.2 CK DAILY KERNEL FILES

MGS CK daily kernels files are just that...a day by day delivery of spacecraft orientation and angular velocity data. NAIF does not merge these into one file as they do with the SPK files. So this task is done by USGS personnel.

We merge all the daily CK files from the first day following the most recently released merged CK kernel from NAIF up the day they are downloaded. This new file becomes $ISISMGSDATA/mgs_sc_map.bc. The file $ISISMGSDATA/mgs_sc_map.bc.log is the output of the NAIF program "brief" on this file.

In order to combine/merge the daily CK files, we have obtained a special program from NAIF that is not part of the toolkit. It is called "dafcat" and it basically takes a list of binary DAF formatted files and concatenates them into a single file. It is included in the ISIS NAIF toolkit.

One more note about the CK daily files produced by NAIF. They are named by the day of the year (DOY) rather than YEAR-MONTH-DAY. This can be a bit annoying to determine the exact day you are interested in if it is not readily available. Each of these daily CK files have a ".lbl" label file associated with it. These label files also do not contain the month or day of the month in them either. (Hint: See the NAIF program "chronos".)

To transfer the daily files, I typically will create a directory path that has ./ck/daily in it and store all the CKs ftp'ed from NAIF there. It will become more apparent why a bit later.

To ftp the daily CK file from NAIF to your ./ck/daily directory use the following set of commands (again, % denotes Unix prompt, "ftp>" denotes ftp prompts, and # for comments):

  % ftp naif.jpl.nasa.gov
# Enter "anonymous" for user name and "your_name@" for password.
ftp> cd /pub/naif/MGS/kernels/ck
ftp> bin
ftp> prompt # Turns prompting off for multiple file get
ftp> mget mgs_spice_c_kernel-2001-*.bc*
ftp> bye

This will get all the daily CK files for the year 2001. You can target specific days of files if so desired. This transfers both the binary CKs and their associated label files.

Once these files have been transfered to your Sun or Sun compatable machine, they need to be concatenated into a single file, converted to transfer format, copied to your Linux or Compaq machine and converted back to binary. The NAIF programs to do this are "dafcat", "toxfr" and "tobin", respectively. You can use either the FORTRAN or C toolkit versions of these applications. These commands will be done using the C version of the programs unless otherwise indicated.

On the Sun system, use the following command to convert the files to transfer format:

First, we make a list of all the daily CK files, one file per line, to a list file. This will be used for input into the special NAIF application "dafcat" which is a FORTRAN application (note the "$FSPICE" logical).

  /bin/ls -1 *.bc > daily_ck.lis
$FSPICE/exe/dafcat mgs_sc_map.bc < daily_ck.lis $CSPICE/exe/toxfr mgs_sc_map.bc mgs_sc_map.bc.xfr

Now copy the file to your Intel Linux or Compaq Alpha machine and convert back to binary format:

  $CSPICE/exe/tobin mgs_sc_map.bc.xfr mgs_sc_map.bc

Also, it is highly recommended to put comments in concatenated/merged CK files that describe the contents. See the NAIF toolkit program, "commnt".

Other NAIF programs that may be of interest are "ckslicer", "spacit", "brief", "spkmerge", and "ckspanit".

4. CONCLUSION

It is important to acquire the USGS version of the NAIF toolkit if only for the "dafcat" program. Users should periodically check for other kernels that are issued new versions and install them in their ISIS system.

Questions can be directed to the Isis Support Center (URL: http://isis.astrogeology.usgs.gov/Isis Support/), or contact:

Kris Becker
kbecker@usgs.gov
USGS
2255 N. Gemini Drive
Flagstaff, Az 86001
(928) 556-7124

----
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Last updated: Jul 14 2006