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Paper: Preliminary Results from Detector-Based Throughput Calibration of the CTIO Mosaic Imager and Blanco Telescope Using a Tunable Laser
Volume: 364, The Future of Photometric, Spectrophotometric, and Polarimetric Standardization
Page: 373
Authors: Stubbs, C.W.; Slater, S.K.; Brown, Y.J.; Sherman, D.; Smith, R.C.; Suntzeff, N.B.; Saha, A.; Tonry, J.L.; Masiero, J.; Rodney, S.
Abstract: We describe the scientific motivation for achieving photometric precision and accuracy below the 1% level, and we present a calibration philosophy based on using calibrated detectors rather than celestial sources as the fundamental metrology reference. A description of the apparatus and methodology is presented, as well as preliminary measurements of relative system throughput versus wavelength for the Mosaic imager at the CTIO Blanco 4-m telescope. We measure the throughput of the optics, filter, and detector by comparing the flux seen by the instrument to that seen by a precisely calibrated monitor photodiode, using a tunable laser as the illumination source. This allows us to measure the transmission properties of the system, passband by passband, with full pupil illumination of the entire optical train. These preliminary results are sufficiently promising that we intend to further pursue this technique, particularly for nextgeneration survey projects such as PanSTARRS and LSST.
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