The Formation Of Satellite Sar Spatial Resolution And Ambiguity Function

Synthetic aperture radar (SAR) has high resolution, and it is not restricted by time, climate, weather and so on. It has been concerned by the aerospace power since 1950s when it was invented. Because its azimuth resolution is restricted by the antenna size, and its range resolution is restricted by the bandwidth of the transmit signal, in recent years, improving space resolution by formation flying satellite system is proposed by some countries or international organizations. For example, TechSat-21 Plan was proposed by the Air Force Research Laboratory in 1998, CartWheel Plan was proposed by French Space Agency in 2003, and Pendulum Plan was proposed by the German Aerospace Center.In this dissertation, improving space resolution utilizing formation flying satellites system and the ambiguity function of spaceborne bistatic SAR are researched.Chapter 1 is the introduction. In this chapter, Synthetic Aperture Radar, formation flying satellites system and SAR are introduced.Chapter 2 gives the difficulty of improving space resolution of the SAR. Range Doppler Algorithm is given too. In this dissertation, Range Doppler Algorithm is used to improve the space resolution.Chapter 3 is the focus in this dissertation. In this chapter, a method of improving azimuth resolution based on spectrum synthesis under line formation flying satellites SAR condition is studied, and the relationship between baseline of formation flying satellites SAR and azimuth resolution is analyzed. On the basis of Chapter 3, the space resolution under circular formation flying satellites SAR is studied. Both azimuth resolution and range resolution can be improved under circular formation flying satellites. Compared with line formation flying satellites, circular formation flying satellites have incomparable advantages.The ambiguity function of spaceborne bistatic SAR is analyzed in Chapter 5. The expression of the ambiguity function is deduced and simulated.