MODIS instrument status and operational activities

The Terra MODIS and Aqua MODIS have been successfully operated on-orbit for a total of more than six and a half years, collecting data for the science and applications communities to develop and enhance their understanding of the Earth/atmosphere system and to support studies of the climate and climate changes. Since its launch in December 1999, the Terra MODIS has experienced several changes of its operational configuration either caused by the failure of individual electronics subsystems or purposely switched for better signal response or data quality. Excluding minor anomalies related to instrument reset events during initial on-orbit operation, the Aqua MODIS has been operating in a single configuration since its launch in May 2002. There are approximately 40 science products that are being produced using the calibrated data sets from each instrument. In addition, several products are generated using the combined observations from both instruments. This paper provides an over-view of Terra and Aqua MODIS instrument status and summarizes those on-orbit operational activities designed and implemented to provide and support instrument calibration and characterization. The assessments of instrument performance are based on the use of on-board calibrators (OBC) and other activities specially developed and implemented by the MODIS Characterization Support Team (MCST) at NASA/GSFC. Both instruments are performing well. During four and a half years of Terra MODIS on-orbit operation, 11 detectors became noisy and one inoperable out of a total of 490 detectors. Except for band 6 at 1.6mu that had many inoperable detectors (identified pre-launch and immediately after launch), there have been no new noisy or inoperable detectors in Aqua MODIS during its two years of on-orbit operation. The sensors' spectral and spatial performance have also been very stable.