campt

This program requires the user supply a "level 1" cube. That is, a cube in raw camera geometry. The user must also enter one of the following coordinates:

      line/sample
      latitude/longitude
    

The program will then compute the other coordinates and various other spacecraft and instrument related information including but not limited to the north azimuth, solar azimuth, spacecraft azimuth, incidence angle, phase angle, emission angle, and resolution. The following is an example of the output given when campt is ran:

Group = GroundPoint
  Filename                   = /usgs/cpkgs/isis3/data/mgs/testData/ab102401.cub
  Sample                     = 1.0
  Line                       = 1.0
  PixelValue                 = 0.0607816
  RightAscension             = 65.749350916052
  Declination                = -18.390093214966
  PlanetocentricLatitude     = 34.444196777763
  PlanetographicLatitude     = 34.760399604837
  PositiveEastLongitude      = 223.84999971299
  PositiveWestLongitude      = 136.15000028701
  BodyFixedCoordinate        = (-2015.9595225544, -1936.6155808127, 1917.2574858384) <km>
  LocalRadius                = 3389756.4767145 <m>
  SampleResolution           = 536.05556350077 <m>
  LineResolution             = 536.05556350077 <m>

  # Spacecraft Information
  SpacecraftPosition         = (-2025.6211429076, -2130.1417975758, 2009.318879871) <km>
  SpacecraftAzimuth          = 0.006855593033889
  SlantDistance              = 214.52515878961 <km>
  TargetCenterDistance       = 3560.6189705415 <km>
  SubSpacecraftLatitude      = 34.354896748841
  SubSpacecraftLongitude     = 226.44072947174
  SpacecraftAltitude         = 170.83335389965 <km>
  OffNadirAngle              = 36.149255932304
  SubSpacecraftGroundAzimuth = 91.64525294858

  # Sun Information
  SunPosition                = (-177337948.13839, 112957442.69098, -33704752.205292) <km>
  SubSolarAzimuth            = 172.30460990873
  SolarDistance              = 1.4234246174889 <AU>
  SubSolarLatitude           = -9.1071705738361
  SubSolarLongitude          = 147.50443340123
  SubSolarGroundAzimuth      = 254.69139701227

  # Illumination and Other
  Phase                      = 120.59515694473
  Incidence                  = 84.106289446623
  Emission                   = 38.288719431206
  NorthAzimuth               = 261.46910874636

  # Time
  EphemerisTime              = -69382819.160519 <seconds>
  UTC                        = 1997-10-20T10:58:37.6570806
  LocalSolarTime             = 17.089704420784 <hour>
  SolarLongitude             = 201.83159041209
End_Group
    

In the output, all positions are in body fixed coordinates. The SubSpacecraftLatitude and SubSpacecraftLongitude make up the subspacecraft point, which is the point on a body which lies directly beneath the spacecraft. The SubSolarLatitude and SubSolarLongitude make up the subsolar point, which is the point on a body's refernce surface where a line from the body center to the sun center intersects that surface. The NorthAzimuth, SpacecraftAzimuth, and SubSolarAzimuth are the values of the angle between a line from the image center to the relative point (North pole, SubSpacecraft Latitude/Longitude, SubSolar Latitude/Longitude respectively) and a reference line in the image plane. The reference line is a horizontal line from the image center to the middle right edge of the image. The angles increase in a clockwise direction. The LocalSolarTime is the time at the current longitude relative to the subsolar longitude, which has a time of 12 o'clock. The SolarLongitude is LSubS, or the seasonal angle.