planspace Documentation

planspace - Create TFILE for plotting Right ascension and Declination
Create the transformation data file (TFILE) for "geom" (see "geom" for
more information) to project LEVEL 1 cubes to a Simple Cylindrical pro-
jection of the right ascension and declination area covered by the cube.
(Camera distortions are also removed.)  The right ascension will be
plotted as longitude and declination will be plotted as latitude.

The purpose of this program is to create a series of images that can be
mosaiced and the right ascension and declination can be displayed using
a program such as qview.  The goal is to find the right ascension and
declination of stars.  If this program is used to create a set of images
to mosaic a "flyby" sequence, the result will be very strange.  The
target of the sequence will show up in several places in the mosaic.
(See the diagram below.)

          x-----> O                O
                 /^                ^  O
                / |      =>        | /
               x  |                |/
                  x                x-----> O

       Flyby sequence           Space projection




         x-----> O                 x-----> O
         x                         |\
         x\               =>       | \
         | \                       V  V
         |  V
         V

   Star search sequence         Space projection


     x is spacecraft position
     O is target
     ---> camera pointing direction
       or
     \
      \   camera pointing direction
       V


WARNING: The sign of the right ascension angles will be reversed for
planets with positive east longitude.

This program does not do the actual transformation of the cube, "geom"
must be run using the TFILE created by this program.  The map resolution
is calculated by the program to retain the full resolution of the LEVEL
1 cube.

PROGRAMMER: Kay Edwards, Q&D Programming for Mark Robinson at NWU

Input cube name
(default extension is .cub)

NONE

Transformation file
(no default extension)

tfile.dat

Center latitude of simp

0.

Center longitude of simp

0.

Image resolution (km/pix)
      or

--

Image resolution (pix/deg)

--

Latitude range
(default=cube range)

--

Longitude range
(default=cube range)

--

ADDITIONAL NOTES:

Parm	Description
FROM	Input cube file name. If the file extension is omitted, then ".cub" will be assumed.
TFILE	This is the name given to a data file needed by "geom". After this program has finished, "geom" must be run to actually transform the cube.
CLAT	This is the center latitude of the Simple Cylindrical projection. This value may be set to the center declination of the cube (see INSTRUMENT_DECLINATION on the labels) to change the aspect ratio of the cube for plotting areas near the pole. Note that CLAT must be the same for all images that will be mosaiced.
CLON	This is the center longitude of the Simple Cylindrical projection. There is probably no reason to pick any value other than 0. CLON must also be the same for all images that will be mosaiced.
KM	Specifies the map resolution in kilometers/pixel. default will be to use DEG to define the resolution.
DEG	Specifies the map resolution in pixels/degree. The default will be to use the focal length to retain the original resolution. If any value is entered for DEG, then the value in KM will be ignored.
LAT	The default procedure is to automatically find the latitude and longitude range on the cube. If you want to enter your own latitude range, the longitude range must be entered also, because if this option is used no range is found on the cube. NOTE: this will be the declination range.
LON	See LAT. NOTE: this will be the right ascension range.