Help for ROVERNAV

PURPOSE
A program to determine rover location and orientation.

EXECUTION
xyznet inp=listoflanderfiles out=tiepointdata archive=x
cat tiepointdata x > archive
rovernav inp=listofroverfiles out=rovernavigation archive=archive

METHOD:

This is an interactive program.
The program will display pairs of stereo rover images one after the other.
The images are displayed with the left eye image on the right and the right
eye image on the left. You can see stereo by crossing your eyes.
NOTE: Input images must be entered in left,right ordered pairs since 
there is no present way of identifying rover stereo pairs.

For each pair select (by clicking the mouse on) existing tiepoint pairs and
relocate them to their correct locations in the rover images.
Each tiepoint pair has it's own color so you can associate tiepoints 
together. Tiepoints come from the tiepoint archive. You cannot create new
tiepoints or delete existing ones.

You must first click near a tiepoint, selecting it.
To assist you in associating tiepoints with real estate the program will then
display below the rover images the image pairs used to create the tiepoint
you selected from the archive. The specific tiepoint you selected will
appear in the lower images to help you identify the object this tiepoint
originally designated. If you still want this tiepoint click on it
again, relocate it, and click a third time to reposition it. You relocate it 
by moving the cursor not by dragging.
If, after moving a tiepoint, you don't want it just click on it again to
undo it.

The program wants you to relocate tiepoints in order to know where the true
camera is located and oriented. Only relocated tiepoints are used in this
analysis.

Three boxes can be clicked on to permit you to:
1. select the next stereo pair.
2. select the last stereo pair.
3. solve for the navigation and restart the program to see the result.
4. exit the program, keeping the lastest navigation solution.

After you exit the program you need to double click on the upper left of the
window to remove it.

Each time you request a navigation solution the program will compute the 
correct rover location from only the tiepoints you moved. The program will then 
purge all the points you relocated and redisplay the archived tiepoints to
permit you to observe the quality of the solution. A good solution results
in the tiepoints overlaying the correct real estate. It will likely require 
several passes to achieve a good solution. If the rover location/heading is
poorly known most archive points will fall outside the f.o.v. You'll
have to move them into the fov by first computing a poor solution with the
points you can see.
Good solutions require four things:
1. At least 3 tiepoints NOT in a line.
2. Points as near to the rover as possible.
3. Final tiepoints overlaying the features they represent.
4. A small residual solution.

After generating a solution you can observe the quality of the fit by clicking
on the solution of choice. In general to create a new solution you must
re-select tiepoints. If you don't re-select tiepoints you can observe other
solutions by just clicking on them since they are all solved for and saved.
When you exit, the latest solution you selected will be saved to the output
file.

You can override the x,y,z,heading,pitch, & roll contained in the picture label
by using the FORCE keyword.

Normally the input consists of a single stereo pair. You can input many stereo
pairs if you wish but they must all be taken from the same rover position and
orientation. It is this single location/orientation which is being solved for.

You have two objective functions to choose from. Your solution is the rover
x,y,z,heading,pitch,roll which minimizes this function.
If Objective=1 you are minimizing the distance between the archive xyz points
and the xyz points your relocated rover image tiepoints result in.
If Objective=2 you are minimizing the distance between where the archive xyz 
points project in the rover images and where your corresponding tiepoints
lie in the same rover image stereo pairs.

When you have relocated as many points as possible the program will perform
three solutions and give you the choice of which one you wish to adopt for
the next iteration (if any). Your choices are:
1. Compute x,y,z
2. Compute x,y,z,heading
3. Compute x,y,z,heading,pitch,roll
You can iterate or move amongst these as you wish.
Remember that the last one you selected is saved to the output file.
To begin another solution you must relocate all you tiepoints again.

The program will write an output file each time you request a solution. When 
you are satisfied just click on EXIT and the last solution will reside in
the file.

The output file contains ascii records, one for each input file. The data
contained within each record is:
Filename,x,y,z,heading,pitch,roll
xyz are in meters, mars local level. X is north, y is east, z is down.
heading,pitch,roll are in degrees. Heading is clockwise from north,
pitch is positive front down, roll is positive counterclockwise facing
forward.

Warning: It has not been possible to verify the positive rotation direction
for pitch and roll from test imagery.