Help for LSTOXYZ

Converts the tiepoint locations stored in a Mark file and written by
program TRACKER either to:

 X,Y,Z,Error   coordinates in the planet reference frame
or
 Lat,Long,Range-radius,error   coordinates on the planet

and writes them into another Mark file. The Mark file can be converted
into a topomap by program TOTOPO.

This program does ranging on two flight project images with 
high quality navigation and generates XYZ coordinates in Km.
in the planet reference frame. It is a member of the MIPL
stereo program suite.

If you have no camera models or spice pointing you can use TOPOMAP
instead to generate relative topography.

Example:
       LSTOXYZ left,right,points out parameters

  where: 
         LEFT is the first input image. This is the first input image
              to program TRACKER. In this case it must be a map projected
              image.
         RIGHT is the second input image. This is the second input image
              to program TRACKER. The second input must also be a map
              projection preferably the identical projection as the first
              input image (non-identical projections are OK except that
              TRACKER will work better if they are identical).
         POINTS is a MARK file containing the tiepoints written by
              program tracker.
              Mark files contain 512 byte records of real*4 data.
              Coordinates are stored in groups of 4 words in the
              order left_line,left_sample,right_line,right_sample...
         OUT is a Mark file containing either:
                  The groups of x,y,z,error
                  values computed by program LSTOXYZ.
                  (see keyword XYZ)
            or
                  The groups of latitude,longitude,range-radius,error
                  values computed by program LSTOXYZ.
                  (the default)
              Mark files contain 512 byte records of real*4 data.
              Coordinates are stored in groups of 4 words in the
              order X,Y,Z,ERROR,X,Y,Z,ERROR...
                 or LAT,LON,RANGE-RADIUS,ERROR...

Important note to users of the output file:
There is a 1:1 correspondence between input Mark and output Mark files.
If an input coordinate is zero then ignore that input and output.
If an input coordinate is not zero but the output coordinate is
zero then the input could not be processed for some reason so 
ignore both input & output for that point. The correspondence
assures that the input line,samp coordinates match the output XYZ's.

Outputs can be zero because:
1. input was zero.
2. the mapping transformation placed a point off or behind the planet.
3. the 3-space vectors were parallel.

METHOD:
LSTOXYZ performs the following steps:
1. Gets the transformation for both input projections (line,samp ->lat,lon)
2. Gets the transformation for both object space images(lat,lon->line,samp)
  For each tiepoint:
3. Convert line,samp to lat,lon in projection space.
4. Convert lat,lon to line,samp in original image object space.
5. Construct two vectors from the spacecraft positions towards
   those line,samp coordinates in the image plane.
6. Compute the closest approach point between the two vectors.
   This is the X,Y,Z value.
7. The miss distance is the 4th value ERROR.

Note the Spice gives the RS vector (s/c position in planet coords)
and the OM matrix (rotation of planet to camera coords).

See Manual Of Photogrammetry , Sec Ed, P50.

OUTPUT UNITS:

  XYZ values are in Kilometers in the planet reference frame.
    Z is the polar spin axis
    X & Y form the equatorial plane.
    X pierces the geoid at the prime meridian (0 longitude).

  LAT is in degrees planetocentric.
  LONG is in degrees West.
  RANGE-RADIUS is in kilometers. It is the difference between the
    range from the XYZ point to planet center and the local
    planetocentric radius of the geoid at that latitude.

  The fourth value (error) is the closest approach point of the
  two vectors in Km. It is NOT the error in elevation.

EXAMPLE: 

         farenc in1
         farenc in2
         map3 in1 a
         map3 in2 b
         tracker a,b m
        LSTOXYZ a,b,m xyz 'XYZ

HISTORY
Written By: J Lorre			jan 91
Cognizant Programmer: J Lorre

PARAMETERS: