Research On The Positioning System Of Search And Rescue And Its Key Techniques

According to the emergency events in the aerospace and other fields, a positioning system of fast search and rescue is designed, and its key Techniques are also researched. The main contributions are as follows:1. By the analysis of the current global satellite search and rescue system, and the analysis of the application environment, a positioning system of fast search and rescue is proposed after some simulations and demonstrations. Its positioning algorithms are based on TDOAs. And a broadcasting system is also designed for it, to send a distress signal and to estimate the TDOAs.2. By the study of positioning algorithms existing and the high dynamic application environment, a new positioning algorithm based on LMS is proposed. It can well adapt to the dynamic environment, in which the number of the rescuing helicopters changes dynamically, and also has good positioning accuracy. Then, the positioning algorithms for the search and rescue system and the estimation precision of TDOA are determined, after analyzing the simulation results.3. A broadcasting system based on spread spectrum technology is designed, in which the frame structure and data rate of the broadcasting information, the signal capture and synchronization algorithms of the receiver are determined. The simulation results show that, in the high dynamic environment, when signal-to-noise ratio is10dB, the probability, of which receiver estimates TDOA successfully, is0.865, and the timing error is less than1.4x10-7s.4. The whole positioning system of fast search and rescue is simulated to verify its feasibility and reliability.