Help for GSPICE

PURPOSE:

GSPICE lists the SPICE data for a specified image.  The program is
currently restricted to Voyager ISS, Galileo SSI, and Cassini ISS.

EXECUTION:

    GSPICE  INP=inputimage  TARGET=IO
 or
    GSPICE  SPACECRAFT=VGR-1  CAMERA=7 	TARGET=IO  	SCET=(year,day,hour,minute,second,msec)
 or
    GSPICE  SPACECRAFT=GLL  CAMERA=1  TARGET=IO  	SCET=(year,day,hour,minute,second,msec)
 or
    GSPICE  SPACECRAFT=CASSI  CAMERA=1  TARGET=IO  	SCET=(year,day,hour,minute,second,msec)
where
    INP is the filename of the image for which SPICE data is to be listed.
    SPACECRAFT is CASSI, GLL, VGR-1, or VGR-2.
    SCET is the shutter-centered SpaceCraft Event Time

If INP is specified and the project is GLL or CASSI, the TARGET parameter
need only be specified if the target name is incorrect in the VICAR label.

If INP is not specified,  SPACECRAFT, CAMERA, TARGET, and SCET must be
specified.

OPERATION:

If INP is specified, the spacecraft ID, camera ID, target name, and
spacecraft event time are retrieved from the VICAR label.  Since the target
name is not present in the Voyager image label, the TARGET parameter is
required for Voyager images.

If INP is not specified, this information must be supplied via the SPACECRAAFT,
CAMERA, TARGET, and SCET parameters.

Planetocentric latitudes and west longitudes are used.  Unless explicitly
stated otherwise, all distances are in kilometers.

DESCRIPTION OF PRINTED SPICE DATA:

Coordinate system is: B1950
    The inertial coordinate system used is Earth Mean Equator 1950 for Voyager
    and J2000 for Galileo and Cassini.

CKNAME=FARE  SPKID=N120 PROGRAM=*NONE* IG.PLT  PLTF 00/00/00
    The C-matrix source is MIPS_FARENC.CK.

GLL    SCLK=420467122  SCET=(1997,309,17,46,25,395)
    The spacecraft, SCLK and SCET times used.

Observation=11JSFEATRK03
    The Observation id from the PA Vicar label keyword for Galileo images.

Camera=2  Focal length= 1501.04 mm  Picture scale=32.8084 pixels/mm
    Camera information

Target=IO           Radii=( 1830.0, 1818.7, 1815.3)
    Target long equatorial radius, short equatorial radius, and polar radius.

Solor range=     790940864. (lat,lon)=(  0.555,169.925)
    The latitude and longitude of the sub-solar point.

Spacecraft range=   806022. (lat,lon)=( -0.096,155.074)
    The latitude and longitude of the sub-spacecraft point.

 C-Matrix:   0.59451884   0.17499144  -0.78480911
             0.56678396   0.60112065   0.56339139
             0.57035369  -0.77976400   0.25819519
    Transformation from camera coordinates to inertial coordinates. 

ME-Matrix:  -0.44974107  -0.89304841  -0.01405499
             0.80900592  -0.40064800  -0.43010536
             0.37847379  -0.20480661   0.90266931
    Transformation from target fixed coordinates to inertial coordinates.

OM-Matrix:   0.40701598  -0.87482715   0.26270795
             0.11248909  -0.23741280  -0.96487373
             0.90646797   0.42227080   0.00177771
    Transformation from target fixed coordinates to camera coordinates.

RS vector=(   -730945.00,   -339690.13,     -1353.79)
    Vector from target center to spacecraft in target coordinates.

RA, DEC, TWIST=(       109.06,       -18.49,       314.53)
    Right Ascension, Declination, Twist Angles of the platform in J2000
    Galileo uses a different definition of Twist than Voyager and Cassini.
    For info see the rotation.req SPICE documentation file.

North angle=285.23 deg clockwise from right
    Orientation of the projected spin axis in the image.

Spacecraft distance from planet=  1199689.
    Distance from planet center to spacecraft.

Computations at (line,samp)=( 505, 514)
 (lat,lon)=(    0.68,  156.20)
 Incidence=  13.73  Emission=   1.37  Phase=  14.87
 Horizontal scale=   47.306  Vertical scale=   47.300 km/pixel
 Slant range=   804192.81 km
 Azimuths: Solar, North, Spacecraft=(      191.60,       92.12,      358.10)

The lighting angles, image resolution, target distance and azimuths are computed
at some convenient point in the image.  For high-resolution images (where the 
target covers the entire field-of-view), the center of the image is chosen.  For
low-resolution images, the target-center is used if it is visible in the image
or if the size of the target is less than the width of the image.  If not, the
computations are performed at the point along the picture margin where the
resolution is highest.

PARAMETERS FOR RETRIEVING CAMERA POINTING FROM SPICE:

The following parameters permit the user to retrieve a specific instance of
camera pointing from the SPICE kernels:

SPICEMODE specifies whether SPICE data is retrieved from LOCAL kernels or
or via the REMOTE SPICE server.  If defaulted, SPICEMODE is set to the value
of the environmental variable DEFAULTSPICE.

CKNAME and CKID are alternative ways to specify the C kernel to be used.  For
example, CKNAME=FARE or CKID=M904 specifies that MIPS_FARENC.CK is to be used.
When specified, the CKID parameter overrides the CKNAME parameter.  If the
camera pointing data is not found in the requested C kernel, the other C kernels
are searched.

Within a given C kernel, there may be a number of different versions of camera
pointing for a given image.  The segment identifier for each version contains
provenance information identifying the creator of the pointing data.  One or
more of the following parameters may be used to retrieve a specific instance of
camera pointing based upon this provenance information:

CDATE specifies the date and time the camera pointing was created.
REQNUM identifies the request number associated with the camera pointing.
PURPOSE identifies the purpose for creating the camera pointing.
PROGRAM identifies the program which created the camera pointing.
SPKID identifies the SP-kernel used to create the camera pointing.
USERID identifies the user who created the camera pointing.
GROUPID identifies the group which created the camera pointing.
INSTITUTE identifies the facility which created the camera pointing.

Complete lists of CK and SPK IDs are located in the xxx_KDB files listed in
the ASCII file assigned the logical name (or environmental variable) 
SPICE_CONFIG_FILE.  These files are project-specific, e.g., GLL_KDB, 
CAS_KDB, etc.  The value of SPICE_CONFIG_FILE being used is defined
by the VICAR system in use as selected by the "select X" command (X = O
for operational system, D for development, T for test, etc.).  The kernels
for systems other than O are not guaranteed to be correct.  If problems are
encountered with the kernels used by "select O", please contact the MIPS
SPICE cognizant engineer.

The above parameters are optional, and if defaulted (or if no data is found for
the requested version), the program will attempt to locate the "best" data
available for the given image.  See the level 2 help (via the TAE tutor mode)
for further details.

Examples:  'LOCAL CKNAME=NAIF specifies that SPICE data be retrieved from
          local kernels using camera pointing from predicts or AACS telemetry.

           'REMOTE CKNAME=FARE INSTITUTE=MIPS SPKID=N015 USERID=ADC retrieves
          the camera pointing created by Amy Culver at MIPS using the SP kernel
          GLL_LONG_2.BSP from file MIPS_FARENC.CK via the SPICE server.  (whew!)

It takes longer to search for SPICE data on the basis of provenance
information.  If all provenance parameters are specified, for example, the
program first searches through all the C kernels for an exact match.  If no
match is found, the search is relaxed by removing the CDATE criteria.  If no
match is found, the REQNUM criteria is removed.  Etc.

EXAMPLES:
  gspice inp=a.img
  gspice spacecraft=gll   target=ganymede  camera=1  	scet=(1996,121,11,10,9,123)
  gspice spacecraft=vgr-1 target=jupiter  camera=7  	scet=(1996,121,11,10,9,123)

PROGRAM HISTORY:
Written By: Gary Yagi, October 1, 1996
Cognizant Programmer: Gary Yagi
REVISIONS: 

14 Jul 2006  lwk  Updated discussion of kernel DB in Help text.
Oct 02, 2002 VRH  Some Cassini fixes, Doc updates.
Sep 01, 2002 GMY  Update VGR and Cassini test cases.  Fix VGR camera s/n.
Dec 07, 2001 GMY  Fix .PDF by adding continuation char to PROJECT keyword.
Nov 28, 2001 GMY  Add Cassini capability.
Jul 23, 1998 TXH  Assigned initial values to parameters FDS and OBSID.
                  Removed unuse variables.
Jun 06, 1998 RRP  Modified call to xvpcnt not to include more then two
                  parameters to make it work on hp platform.
Apr 30, 1988 GMY  Modify to work with VGR SPICE files.
Jan 22, 1998 GMY  Calculate phase, incidence, and emission on ring.
Jan 12, 1998 HBM  Added the printing of the ra, dec, twist,and azimuth values
                       and resolved Voyager OBSID RING issue.
Nov 24, 1997 HBM  Added new picscale routines into GSPICE.  
                       Still need to resolve OBSID for Voyager and port for SGI
Dec 30, 1996 OAM  Moved spice2convev and lighting to picscale.com.

PARAMETERS: