Results and Lessons from MODIS Thermal Emissive Bands Calibration: Pre-launch to On-orbit

摘要

The Moderate Resolution Imaging Spectroradiometer (MODIS) is a major instrument for NASA's Earth Observing System (EOS), currently operating on-board the EOS Terra spacecraft, launched in December 1999, and Aqua spacecraft, launched in May 2002. MODIS is a whiskbroom scanning radiometer using a double-sided paddle wheel scan mirror. It makes measurements in 36 spectral bands with wavelengths from visible (VIS) to long-wave infrared (LWIR). Bands 20-25 and 27-36 are the thermal emissive bands (TEB) covering wavelengths from 3.5 to 14.4μm. During pre-launch thermal vacuum measurements, a laboratory blackbody calibration source (BCS) was used as the primary calibration source for the TEB. For on-orbit operation, an on-board blackbody (BB) source and a space view (SV) port are used together for the TEB calibration on a scan-by-scan basis. This paper provides an overview of Terra and Aqua MODIS pre-launch and on-orbit calibration and characterization activities, methodologies, data analysis results, and lessons learned for the thermal emissive bands. It focuses on major issues that could impact MODIS TEB calibration and data quality. Results presented in this paper include detector noise characterization, response versus scan angle (RVS), and response versus instrument and focal plane temperatures. Similar discussions for the MODIS reflective solar bands (RSB) are presented in a separate paper in these proceedings (Xiong et. at).