Preliminary investigations concerning a 90 GHz radiometer satellite experiment

The preliminary investigations in this paper are aimed to realize a satellite experiment by means of a 90 GHz radiometer. Therefore, on the basis of a computer model the radiation temperatures of the object classes sand, vegetation, concrete and water are determined for different atmospheric conditions. Measurements with an uncooled airborne 90 GHz radiometer allow a quality test with respect to the model results. To accomplish the planned experiment a special null-balancing radiometer is proposed. In the case of null-balancing failure this system also can be operated as total power radiometer. This procedure reduces the probability of a complete system drop out.