A new model of dealing with solar radiating disturbance is put forward and a systematic explanation to the antenna noise temperature analysis in case of solar radiating disturbance is made.

Three subjects-UWB radar antenna, UHF/VHF band receiver noise temperature, and the target detection from background, which are main factors in UWB SAR range equation, are studied.

Antenna system noise temperature and antenna efficiency are the most important items in the system debugging and checking before the VLBI observation.