Software Progress

[Tom Droege <tdroege2@earthlink.net>]

Slowly the software in my head is getting into a file and is being debugged.

I now have the software working that reduces each image to an individual 
.cal file.  For each .cal file I am looking at the refcat.dat stars that it 
contains.  I am using DS-24 Set #3 as a test file.

When I compare the .cal magnitude with the refcat.dat magnitude, if find 
that the RMS value (sigma) is rather large and rather uniform for the 49 
images of DS-24.

Values for V  are typically 0.15 mag ranging from 0.14 to 0.16 for the 49 
images.  Values for  I are typically 0.25 mag ranging from 0.24 to 0.27.  I 
think this tells us what we already knew.  We need a better reference 
catalog.  Since DS-24 moves around in RA-Dec space, the refcat.dat stars 
vary from image to image.  Typically there are 700 to 900 stars in 
refcat.dat for DS-24 #3.

I think DS-23 #3 is the cleanest set with respect to clouds.  At least the 
cloud removal stage did not reject any images.  I did have the limits set 
rather high.  I will run it again with a tighter cloud rejection limit.

There are enough refcat stars available that I can sort out the ones with 
the smallest error.  There must be an optimum point between many stars with 
large error and too few stars to get a good fit.  I also want to go back 
and try to bootstrap the refcat again.  There are now lots of fun things to 
do.

Tom Droege