Applications and Results of MODIS Lunar Observations

摘要

Since launch, both Terra and Aqua MODIS have been making regular lunar observations with a primary objective of providing an independent stability monitoring for the reflective solar bands (RSB) calibration. To a large extent, this approach is based on the fact that the Moon has extremely stable surface reflectance properties. When combined with a lunar radiometric model, the applications of lunar observations can be significantly enhanced. Using MODIS as an example, this paper discusses various applications developed from its lunar observations. In addition to the RSB stability monitoring, MODIS lunar observations are regularly used to examine its calibration consistency between Terra and Aqua MODIS and to track the sensor's band-to-band registration (BBR) stability. Examples also presented in this paper include optical leak and electronic crosstalk characterization for MODIS thermal emissive bands (TEB) and shortwave infrared (SWIR) bands. Results from multi-year lunar observations show that the MODIS RSB calibration stability has been satisfactory when compared to its solar calibration, and that Terra and Aqua MODIS are calibrated consistently to within ±1% for most RSB. The spatial characterization results derived from MODIS lunar observations agree very well with that determined from its on-board calibrator. It is clear that the applications and results of MODIS lunar observations presented here will serve as good examples or references for other sensors that also make use of lunar surface observations.