[daip] BSCALE BZERO

[R. Niruj Mohan]

Hello,

I am a bit confused about the usage of SCALE and ZERO in AIPS and FITS.

Am I right in assuming that ...

1. AIPS understands BSCALE and BZERO and the flux I get from IMVAL or 
IMSTAT is correct. But if I access these values through GETHEAD then aips 
doesnt understand them.

2. EXPLAIN GETHEAD mentioned ISCALE and IZERO instead, and if I 
change the keywords in the FITS files from B to I then imheader includes 
that info. *But* the flux doesnt change, even after RESCALE, which means 
that ISCALE and IZERO have no effect.

3. When I use cfitsio to read a file which has BSCALE and BZERO in them 
then the image read in automatically has these corrections done.

Atleast thats what I figure from experimenting. Would be helpful if you 
tell me if thats indeed so.

thanks
Niruj