Hi,
Even I wanted to know what is DCTA, FITS, FACTS. I just searched for it.
FITS: FITS (Flexible Image Transport System) is a data format designed to provide a means for convenient exchange of astronomical data between installations whose standard internal formats and hardware differ.
. Please refer the follwing sites for more information.
FITS:-
http://fits.gsfc.nasa.gov/fits_intro.html
No idea about DTCA and FACTS.