WFPC2 Technical Instrument Report 97-10:

WFPC2 Photometry from Subtraction of Observed PSFs

-Surdej, Remy, Baggett, and Wiggs

Based on observed PSFs from the WFPC2 calibration programs, a series of PSF subtraction tests have been performed and the resulting photometry analyzed. We find that using a composite observed PSF, constructed from optimally selected PSFs based on location and breathing values, yields single photometric values affected by an RMS of ~0.01-0.02 mag. While resampling does not appear to have much of an effect on the photometric results, the color of the PSF employed is important.

The Complete Paper (PDF 0.58 MB) is available; or contact help@stsci.edu.