The Research And Application On Algorithm Of Phase Unwrapping In Interferometric Synthetic Aperture Radar

Subsidence caused by mining is one of the common destructive disasters in mining area, ground collapse of mined-out area will not only affect the local economy development, but also be a threat to people’s lives and property safety. Therefore, it is of great significance to monitoring effectively and regularly research of mining area. The traditional settlement monitoring methods have leveling measurement and GPS measurement, but each of the two methods has great limitations. Synthetic Aperture Radar Interferometry(In SAR) technique is a great potential satellite observation for earth technology, it has the advantage of large range,all day,all-weather,quickly getting the data, having a broad application fields and practical value. However, in the process of In SAR signal processing, wrapped phase limit in the [-π,+ π), therefore, wrapped phase needs to restore the fuzzy integer times cycle phase. Because the accuracy of unwrapping directly affects the DEM and deformation results.Therefore, how to obtain the high-precision unwrapping phase for In SAR measurement technology is particularly important. Based on this, this paper focuses on three kinds of classical phase unwrapping algorithms, and puts forward an improved phase unwrapping algorithm based on hybrid leapfrog algorithm.The main research works are as follows:(1) the paper analysises the characteristics and applicability of path-following phase unwrapping algorithm and LS phase unwrapping algorithm, and network planning phase unwrapping algorithm. When doing phase unwrapping, people can choose the appropriate phase unwrapping algorithm according to the characteristics of the data,.(2) Aiming at the shortcomings of the classic Goldstein branch cutting method, a new method of phase unwrapping solution is constructed. The paper uses simulated data and different wavelengths real data to validate the improved algorithm, the result shows that the algorithm can effectively unwrap.(3) the paper develops a set of phase unwrapping system based on the Matlab language,and adds visual module of image manipulation, quality evaluation to the data processing module,implementing comparison and analysis of improved algorithm and other common phase algorithms in the system.(4) Finally, the paper obtains the ground deformation caused by mining of 9310 working face of Nantun mine area and the subsidence basin’s dynamic evolution process with time-series D-In SAR technique. By comparing the leveling data, result shows that monitoring accuracy of D-In SAR technology can meet the requirements of general coal mining subsidence monitoring.