Searching And Tracking Aerospace Targets Based On Array Antenna

21st century is an era of rapid advancement for avigation and spaceflight technology. More and more moving targets such as UAVs and satellites appear in the outer space.These targets can be categorized into two: cooperative targets and non-cooperative targets. How to detect and track these targets is a hotspot topic.Non-cooperative targets do not radiate electromagnetic wave.A target is located by echoing radar wave. It is well known that the resolution of traditional radar is very low. The target is judged by analyzing the Doppler and time-delay information. As for angle information, radar cannot distinguish two close targets which are located in the mainlobe of radar if they have the same Doppler and time-delay information. So it is difficult for electronic countermeasures.Cooperative targets are searched and tracked by using narrow beam pattern and large magnify antenna. Multi-satellite will appear in the observing and controlling area of one earth station. This require the earth-station to track and control multi-satellite simultaneously. If we track satellite by the traditional narrow beam antenna, that should cause the jumping tracking between multi-aircraft. That is difficult to achieve by the immense antenna boot and the follow-up system.Much has been researched to solve these problems by scholars home and aboard. They have put forward many algorithms and designed experiment platforms. With the development of array processing technology, the performance of detecting and tracking aerial targets will reach a new level.This dissertation is based on Chongqing Academician Fund Project(microwave imaging applied to search aerospase targets), and Defence Pre-research Project (research of small satellite TT&C system). In this dissertation a method about multi-beamform tracking system based on array antenna is put forward. Some research work is as follows:Firstly, the concept of array processing is introduced and three common array structures are analyzed. It also discusses how to judge the source number.Secondly, this dissertation introduces the direction of arrival estimation with special discussions on MUSIC and ESPRIT and the estimation of the coherent multi-path sources.Thirdly, digital beamforming is achieved by changing the weighting coefficient of...