Research On Signal Processing Algorithm Of Electronic Fence System For Surveillance Of Space Targets

Surveilling, cataloging space targets and forecasting the possible collision, can protect normal space activities of human beings. And electronic fence system as an important tool of surveilling space targets, has received widespread attention at home and abroad. Signal processing technology is one of the key technologies in the electronic fence system, the merits of the signal processing algorithm has an important influence on the performance of the system. So researching on signal processing algorithm of electronic fence system for surveillance of space targets is very necessary.Firstly, we establish the double electronic fence model and make necessary settings for the fence on the basis of related research from home and abroad. And analyse the dynamic characteristics of the space targets when passing through the fence, from aspects of theory and statistics. Based on the work, an orthogonal coding waveform which combines two series of pseudo random code with different code rates is chosed as emission waveform. Then, based on the model of the baseband echo signal, this paper analyses the accumulation loss of the returned signal, points out the factors that can degrade the accumulation and analyses the loss. Furthermore, according to the characteristics of the space targets when passing through the fence and the impact on accumulation, a kind of signal processing algorithm which divides distance into segments for capturing targets quickly is provided in this paper. And it is compared with the traditional algorithms of parallel code phase and parallel frequency capture, finding out that it has the least computation under the same acquisition accuracy. At last, this paper focuses on the algorithm of velocity and distance measurement. The code Doppler compensation method is given, the corresponding relationship between the measured distance value and the time when space targets pass the fence is analysed, and a method of searching the start time and end time of target signal is proposed. From the method, the signal to noise ratio and the measuring accuracy are improved. And the validity of the proposed method is verified by Matlab simulation.