The need to understand and monitor climate change has led to proposed radiometric accuracy requirements for space-based remote-sensing instruments that are very stringent and currently beyond the reach of many Earth orbiting instruments. A major problem is quantifying changes in sensor performance that occur from launch and during the mission. To address this problem on-orbit calibrators and monitors have been developed, but they too can suffer changes from launch and the harsh space environment. One potential solution is to use the Moon as a calibration reference source. Already the Moon has been used to remove post-launch drift and to cross-calibrate different instruments, but further work is needed to develop a new model with low absolute uncertainties capable of climate-quality absolute calibration of Earth observing instruments on orbit. To this end, we are proposing an Earth-based instrument suite to measure the absolute lunar spectral irradiance to an uncertainty* of 0.5 % (k=1) over the spectral range from 320 nm to 2500 nm with a spectral resolution of approximately 0.3 %. Absolute measurements of lunar radiance also will be acquired to facilitate calibration of high spatial resolution sensors. The instruments will be deployed at high elevation astronomical observatories and flown on high-altitude balloons in order to mitigate the effects of the Earths atmosphere on the lunar observations. Periodic calibrations using instrumentation and techniques available from NIST will ensure SI-traceability and low absolute radiometric uncertainties.
Citation: Journal of Research (NIST JRES) - 117.011Report Number:
NIST Pub Series: Journal of Research (NIST JRES)
Pub Type: NIST Pubs
moon, radiometry, satellite sensor calibration