The Frequency Selection Consideration for the Low Orbit Space Based Radar

Space based radar (SBR) has been researched intensely for many years, because it can provide global surveillance without time and space limit. But the enormous expenses delay its realization. In order to decrease its cost and improve its performance, a lot of works have been done, such as the radar system design, the signal processing method research and the constellation design for the world-wide coverage, etc. But few works have been done about the detailed consideration of the frequency selection of SBR. In fact, the frequency selection is closely related to the SBR´s functions, performance and cost. Here, the system characteristics are analyzed for the monostatic SBR in low earth orbit with different frequencies, including L, S, C and X bands. The size and weight of the antenna and the power consumption of the system are considered. The SBR has some different modes of operation according to the different missions, including SAR mode, searching mode and tracking mode. And the wide area searching mode makes demand of the largest power aperture product (PAP). To realize the certain area coverage rate which is according to a certain angle coverage rate (ACR) in space, the SBR needs the corresponding PAP. The weight and primary power of the SBR can be estimated based on the needed PAP.