Evaluation of the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager Sounder (SSMIS)

The defense meteorological satellite program (DSMP) successfully launched the F-16 spacecraft carrying the first special sensor microwave imager sounder (SSMIS) on October 18, 2003. SSMIS provides for the first time, atmospheric soundings that are derived by an instrument with a constant viewing geometry, in lieu of the more traditional cross-track, dwell and step-stare instruments such as the heritage DMSP and NOAA AMSU instruments. In addition, the conical scan features constant pixel resolution yielding exciting high resolution imagery. On-orbit SSMIS data indicates that the instrument is generally performing to specification. The presence of unexpected residual calibration anomalies was found during the sensor calibration and validation (Cal/Val) period and attributed to solar illumination of the warm load tines and reflector self-emission. The warm load errors have been partially mitigated and in progress for the reflector emissions. Mitigation appears to be necessary in order to achieve the full utility of SSMIS data, particularly for the atmospheric sounding EDRs and numerical weather prediction.