Design and development of ground calibration targets for the MetOP-SG microwave sounder payload

We report on the reflection properties of calibration targets required for calibrating the radiometric performance of the Microwave Sounder instruments for the MetOp-SG satellites prior to launch. Both fixed temperature, 80 K, and variable temperature, 80-315 K, targets are required to perform this task. The specifications, the preliminary baseline design of the target structure and its measured reflectivity are presented in this paper.