Analysis of the Special Sensor Microwave Imager/Sounder (SSMIS) Fields-of-View on DMSP F16

The Special Sensor Microwave Imager/Sounder (SSMIS) calibration and Earth scene fields-of-view (FOV) are examined using sensor diagnostic modes, a graphic simulation of the SSMIS and spacecraft vehicle, and an electromagnetic analysis of the SSMIS antenna. The on-orbit FOV for each calibration target was found to be larger than the sample locations utilized by the flight software for calibration suggesting that additional observing time for the each target is available. The optimum calibration sampling location appears to be slightly offset from the current sampling. However, it is not expected that this will result in degraded performance. The SSMIS Earth scene FOV was found to have noticeable edge-of-scan biases for several channels. The biases were examined and determined to be due to intrusions of the antenna feed FOVs of the main reflector antenna caused by the SSMIS calibration targets and their associated multilayer insulation (MLI) blanketing in the final flight configuration. A simple algorithm to address the edge-of-scan biases is applied and found to correct the biases to within ~0.1-0.2 K.