Development of a multispectral albedometer and deployment on an unmanned aircraft for evaluating satellite retrieved surface reflectance over Nevada’s Black Rock Desert
AuthorBoehmler, Jayne Michelle
AdvisorArnott, William P
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Accurate atmospheric aerosol characteristics derived from satellite measurements areneeded over a variety of land surfaces. Inhomogeneous and bright surface reflectanceacross California and Nevada may be a contributing factor in the discrepancies observedbetween ground based and satellite-retrieved atmospheric aerosol optical depth (AOD).We developed and deployed a compact and portable instrument to measure albedo toevaluate a major factor that influences the accuracy of AOD retrievals. The instrumentfunctions as a spectral albedometer using two Hamamatsu micro-spectrometers with aspectral range from 340 –780 nm for measuring incident and reflected solar radiation atthe surface. The instrument was operated on an unmanned aircraft system (UAS) tocontrol areal averaging for comparison with satellite derived albedo from NASAModerate Resolution Imaging Spectroradiometer (MODIS) and Land Satellite 7Enhanced Thematic Mapper Plus (Landsat-7 ETM+). The instrument was deployed onOctober 5th, 2017 under clear skies over Nevada’s Black Rock Desert to investigate aregion of known high surface reflectance. It was found that satellite retrieved surfacereflectance underestimated measured surface albedo at this location, indicating the needfor more albedo measurements to validate satellite retrievals over areas of complexterrain in the Western U.S. This study demonstrates the viability of obtaininghyperspectral surface albedo measurements via UAS as an intermediary between fixedpointground measurement and space-borne observations.