The airborne LUnar Spectral Irradiance (air-LUSI) mission and calibration of ocean observations from space

Kevin Ross Turpie1, Steve Brown2, John T Woodward3, Andrew Gadsden4, Thomas C Stone5 and Andrew Newton4, (1)University of Maryland Baltimore County, Goddard Earth Sciences Technology and Research (GESTAR) II, Baltimore, MD, United States, (2)National Institute of Standards and Technology Gaithersburg, Sensor Science Division, Gaithersburg, MD, United States, (3)National Institute of Standards and Technology Gaithersburg, Gaithersburg, MD, United States, (4)University of Guelph, Mechanical Engineering, Guelph, ON, Canada, (5)US Geological Survey, Flagstaff, AZ, United States
The Moon plays an important role in calibrating spaceborne ocean observing instruments. The USGS RObotic Lunar Observatory (ROLO) model represents the most precise knowledge of lunar spectral irradiance and is used frequently as a relative calibration standard for Earth observation by space-borne sensors. However, 5-10% discrepancy reported between ROLO predictions and calibrated satellite lunar observations limits ROLO as an absolute radiometric reference. The objective of airborne LUnar Spectral Irradiance (air-LUSI) mission is to make SI-traceable measurements of lunar spectral irradiance with unprecedented accuracy from a high-altitude aircraft. Such careful characterization of the Moon, as seen above the atmosphere, will improve it as a stable and consistent absolute calibration reference and help us better understand and possibly improve ROLO uncertainty. The results would be transformational for lunar calibration for Earth observing satellites, bring new insight to ocean vicarious calibration, and be especially beneficial to ocean observation from space. Because of the high sensitivity of passive VNIR ocean remote sensing to calibration, improvement of lunar calibration could directly affect upcoming PACE and JPSS (VIIRS) missions, and retrospectively affect the SeaWiFS, EOS (MODIS), and S-NPP (VIIRS) data records.