PRECISE THROUGHPUT DETERMINATION OF THE PanSTARRS TELESCOPE AND THE GIGAPIXEL IMAGER USING A CALIBRATED SILICON PHOTODIODE AND A TUNABLE LASER: INITIAL RESULTS
- Department of Physics, 17 Oxford Street Harvard University, Cambridge MA 02138 (United States)
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg MD 20899 (United States)
We have used a precision-calibrated photodiode as the fundamental metrology reference in order to determine the relative throughput of the PanSTARRS telescope and the Gigapixel imager, from 400 nm to 1050 nm. Our technique uses a tunable laser as a source of illumination on a transmissive flat-field screen. We determine the full-aperture system throughput as a function of wavelength, including (in a single integral measurement) the mirror reflectivity, the transmission functions of the filters and the corrector optics, and the detector quantum efficiency, by comparing the light seen by each pixel in the CCD array to that measured by a precision-calibrated silicon photodiode. This method allows us to determine the relative throughput of the entire system as a function of wavelength, for each pixel in the instrument, without observations of celestial standards. We present promising initial results from this characterization of the PanSTARRS system, and we use synthetic photometry to assess the photometric perturbations due to throughput variation across the field of view.
- OSTI ID:
- 21454878
- Journal Information:
- Astrophysical Journal, Supplement Series, Vol. 191, Issue 2; Other Information: DOI: 10.1088/0067-0049/191/2/376; ISSN 0067-0049
- Country of Publication:
- United States
- Language:
- English
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