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27 January 1997 Results of dark target vicarious calibration using Lake Tahoe
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The ability to conduct in-flight absolute radiometric calibrations of ocean color sensors will determine their usefulness in the decade to come. On-board calibration systems are often integrated into the overall system design of such sensors and have claimed uncertainly levels from 2-3 percent, but independent means of system calibration are desirable to confirm that such systems are operating properly. Vicarious methods are an attractive means of this verification. Due to the high sensitivity of ocean color sensors, the use for bright reflectance surfaces often results in sensor saturation. Low reflectance targets, such as water bodies, should therefore be used. This paper presents the results of sensitivity studies of the reflectance- and radiance-based approaches when applied to a water target and method uncertainties for calibrations of the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS). The paper also present the results of a field campaign which took place at Lake Tahoe in June 1995. This lake represents a typical oligotrophic water body and has the advantage of being located at a high elevation where tropospheric aerosol loading is low. Aircraft-based radiance data and surface measurements of reflectance are sued to calibrate SeaWiFS- simulated bands from Advanced VIsible and Infrared Imaging Spectrometer (AVIRIS) data. Atmospheric characterization is obtained using solar extinction measurements, surface-level atmospheric pressure readings, and columnar gaseous absorber amounts at sensor overpass. The measured radiances are transferred to the top of the atmosphere using a radiative transfer code which fully computes the contributions of multiple scattering by the atmosphere. The results are compared to those obtained form a laboratory-based calibration of AVIRIS.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Robert John Parada Jr., Kurtis J. Thome, and Richard P. Santer "Results of dark target vicarious calibration using Lake Tahoe", Proc. SPIE 2957, Advanced and Next-Generation Satellites II, (27 January 1997);

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