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Hubble Space Telescope
PSF Measurements

Q.: What measurements of the NICMOS PSF will be made as part of the routine calibration program? When do we recommend that users obtain their own measurements of PSFs?
A.: There are no present plans to for PSF measurements in the NICMOS calibration program. However, data available for other programs such as the absolute photometry program has useful data in all filters.

The Tiny Tim software package has the ability to generate NICMOS PSFs.

The PSF is time dependent on several different timescales, some of which are difficult or impossible to model. In addition, it is possible that the PSF will vary with position on the array. For these reasons, observers that require a very precise measurement of the PSF, must make that measurement themselves using time from their TAC allocation.