REG Files

Description

REG files are written by stella. Stella writes out a REG files for each image in which stella successfully correlates stars. REG files contain information about the pixel/line locations of stars in images and camera information. The REG file list the CX CY CZ that you solved for, the predicted CX CY CZ, and then lists information for each star on a separate line. The REG files are used by distortion to compute an updated camera model, which can then be used in INIT_LITHOS and make_sumfiles.txt. REG files live in the REGFILES directory, which is parallel to LMKFILES, SUMFILES, etc.

If a .REG file already exists, stella will use that information as a starting point when you re-run stella. If you want to start an image totally afresh, you must delete the pre-existing .REG file.

Warning! If you have an existing REG file and then re-run the image through stella and do NOT solve for pointing, stella will delete the existing REG file!

Stella names REG files as PICNAME.REG.

An annotated .REG file

   -0.9303361   -0.1242768    0.3450073    -0.9302355   -0.1243779    0.3452419          Cx, C0x                  --> The solved-for Cx and the predicted Cx. 
    0.3498056   -0.5830977    0.7332347     0.3500547   -0.5830538    0.7331507          Cy, C0y                  --> The solved-for Cy and the predicted Cy.  
    0.1100489    0.8028402    0.5859496     0.1101069    0.8028564    0.5859164          Cz, C0z                  --> The solved-for Cz and the predicted Cz.  
    0.1078023    0.8029705    0.5861886  1005.233   696.014    -0.092     0.073    150822     W PX LN dx dy catno --> each line in this section of the REG file
    .                                                                                                                 corresponds to a star. The columns are
    .                                                                                                                 a unit vector to the star (first three columns),
    .                                                                                                                 the pixel/line location of the star in the image
    .                                                                                                                  (next two columns), and then the pixel/line residuals
   etc., one line in the file for each star that correlated in the image                                               for the star (next two columns), and star catalog number (last column)
END             39    -0.014     0.067    -0.266     0.316  2628.33430                                            --> The last line of the file says how many stars exceeded
                                                                                                                      the correlation limit (39, in this case). The next three
                                                                                                                      numbers are the rotation about the X, Y, and Z axes in units
                                                                                                                      of milliradians. The Z-axis rotation is a twist. 
                                                                                                                      The second-to-last entry is the RMS pixel residual between
                                                                                                                      predicted and observed star locations.
                                                                                                                      The last term is the focal length in mm solved from this image.