Study On Passive Location Of Single Satellite Based On Doppler Measurement

Single satellite passive location technology which have been attached importance by many countries plays an important role in the modern war, because of its concealment, less space and time limit and many other advantages. The passive location technique using Doppler information has the characteristics of low cost, less load, no special requirements for satellite attitude, is the key of this study. However, due to the far distance of the satellite platform, it is difficult to measure the signal parameters because of the small signal energy and low signal to noise ratio. In order to solve the above problems, this dissertation focuses on two kinds of high precision measurement technology of Doppler information, and the corresponding positioning method:1. This dissertation introduces the research background of single satellite passive location technology, discusses the advantages and disadvantages of different positioning systems. The motion model and signal model of single satellite passive location are established, and the Doppler characteristic of the signal is simulated and analyzed. This paper demonstrates the feasibility of using the signal Doppler characteristics to position,expounds the basic principle, and puts forward a method of locating the solution based on the two-dimensional grid search.2. A single satellite passive location technique based on Doppler frequency is studied. In order to solve the problem of large measurement error and low frequency resolution, the Chirp-Z transform method is used to realize the frequency spectrum refinement, which improves the accuracy of the frequency measurement of FFT.Furthermore, based on the results of frequency measurement, the geometric precision(GDOP) distribution of the location is simulated, and the influence of various parameters on the positioning performance is analyzed. The simulation results show that the proposed algorithm is two orders of magnitude lower than the FFT algorithm, and can achieve the accurate positioning error less than 1%.3. A single satellite passive location technique based on Doppler frequency change rate is studied. As for parameter measurement, a method is proposed for high frequency signal Doppler frequency change rate measurement method, this method takes into account the effect of Doppler frequency of two derivative, through several conjugate multiplication extracted signal Doppler frequency change rate. In the aspect of positioning performance, the corresponding geometric precision (GDOP) distribution map is drawn according to the algorithm proposed in this chapter. The simulation results show that the accuracy of the proposed algorithm is higher than that of the proposed algorithm under the condition of high carrier frequency, and the relative error is less than 1%.4. The computer simulation experiment of single satellite passive location is designed and implemented. And use software to simulate the process of two kinds of single satellite passive positioning satellite, for different orbit height and different carrier frequency signals of contrast experiments, achieve excellent results, verify the effectiveness of this algorithm.