Reply To: Software for photometry (image calibration)

Forums Photometry Software for photometry (image calibration) Reply To: Software for photometry (image calibration)

Mr Ian David Sharp

So the image it outputs, is that a calibrated image? Is it possible to tell?
What does the software do to the original uncalibrated lights?

Hi Kevin,

ASTAP does nothing to your uncalibrated lights and it creates calibrated copies with “_cal” on the end of the file names.

If you look at the FITS headers of the calibrated files, you will see something as shown below towards the end of the header. In my test I only selected my master dark and master flat files and you can see resulting CALSTAT = ‘DF’. Also the COMMENT 1 field indicates it was calibrated by ASTAP.

What do you see in the CALSTAT field when you use your flat-darks?


COMMENT 1 Calibrated by ASTAP.
PEDESTAL= 5.000000000000E+002 / Value added during calibration or stacking
DARK_CNT= 1 / Darks used for luminance.
FLAT_CNT= 1 / Flats used for luminance.