[fme] Determination of Lunar Coordinates from Satellite Photos

[Charlie Kapral]

Hi,

I am trying to determine the position of lunar features using 
photogrammetry. Ifm using a photogrammetry system from Penn State 
University entitled gWolfPack for Windowsh found at 
http://surveying.wb.psu.edu/psu-surv/free.htm, which allows the 
digitization of photos to determine the X and Y points of selected 
features on a photograph and gAdjust for Windowsh, at the same 
website, which performs a coordinate transformations on the .PTS 
output file created by gWolfPack for Windowsh. The features that Ifm 
selecting as my control points are ULCN control points and my 
measured points are other ULCN points (as a check) and lunar domes. 
The photos that I am using are photos taken by the Lunar Orbiter IV 
spacecraft.

The process that I am using is as follows:

1. Calculate the X, Y and Z for each Control Point as follows:

   X = R * Cos(Latitude) * Cos(Longitude)
   Y = R * Cos(Latitude) * Sin(Longitude)
   Z = R * Sin(Latitude)

2. Launch WolfPack for Windows
3. Select gProgramsh then gPhotogrammetryh then gDigitizeh.
4. Select the name of the photo to be measured then click on gOPENh.
5. Select a filename then click on SAVE.
6. Select a Cursor type in gCursor Selectionh if desired.
7. Place cursor over 1st control point then click. Enter the name of 
the control point then click SAVE POINT.
8. Continue with the rest of the control points.
9. Then do the same for the points to be measured.
10. When finished with the points to be measured, click on CLOSE.
11. WolfPack for Windows will create a .PTS file containing the X 
and Y positions for the features measured.
12. Exit WolfPack for Windows.
13. Launch Adjust for Windows.
14. Select the .PTS output file to open then click on OPEN.
15. Type in a TITLE on 1st line. Ex: gTest Measurements of 
Flamsteedh.
16. Type in the number of control points on the 2nd line. Ex: g5h.
17. Type in the X and Y coordinates calculated in Step 1 for each 
control point as the next lines.
18. Finally, add the .PTS measured points after them.
19. Select gProgramsh then gCoordinate Transformationsh then g2-D 
Projective Coordinate Transformationh.
20. Click on gPrint Matricesh and gStatisticsh then click on OK.
21. Select the name of the .PTS output file to be processed.
22. PRINT results. The results are the transformed X and Y 
coordinates of the control and measured points.
23. I then use the following to calculate the longitude and 
latitude? of the measured points:

   Longitude = Tan-1 (Y/X) 

   Latitude    =  ??????
        _____________
   R = ã X2 + Y2 + Z2

And, herefs where I need help. 

1. Is a 2-D Projective Transformation the correct transformation? Or 
should I be using a 3-D transformation (projective, conformal or 
affine?)?
2. How do I then calculate the lunar latitude of the features from 
the transformed X and Y, (or X, Y and Z) coordinates?????

I would GREATLY APPRECIATE any help you could give me. THANK YOU 
VERY MUCH!!!!!

Charlie Kapral










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