| Natural calamities such as landslides and mud-rock flow that have seriously threatened people’s life and property happen frequently in China.Both the conventional field sensor networking measurement and GPS remote sensing monitoring have failed to provide careful space extension information of landslides and cannot be applied to the area with high risks or the area that hasn’t formed landslides.Moreover,it costs much build this kind of device,it is difficult to maintain it and it also cost much in the process of using.Since there are a lot of shortcomings in traditional detection methods,some scientific and technical workers have put forward the ground-based interferometric synthetic aperture radar(GB InSAR),which has been a hot topic.Since this kind of technology has only been developed recently,there are several problems and difficulties that need to be solved.A study on the fast imaging algorithm of GBInSAR and the hardware platform concrete realization of GB-InSAR will be carried out in this dissertation.The main content and innovation points are as follows:(1)In terms of the analysis of several kinds of existing GB-InSAR imaging algorithms,it has been discovered that near-site observation and fast imaging can not be realized synchronously.As a result,a new GB-InSAR fast imaging algorithm based on the high-order Taylor expansion and Non-Uniform FFT is put forward in this dissertation.The non-linear phase approximation is carried out upon the slant-range term in the echo expression according to the multi-variable high-order Taylor expansion theory.Then the concept of general Keystone transformation is presented so as to handle the coupling between azimuth and range.Due to the non-uniform of data,image focusing can only be carried out thorough the traditional inverse Fourier transformation.However,because the process of applying this method is complicated and it involves a large amount of computation,the advantage of original fast imaging algorithms has lost.Hence,the concept of Non-Uniform FFT is presented later in this dissertation so as to carry out fast Fourier transformation upon the non-uniform echo data matrix.Finally,the goal of carrying out fast imaging upon far filed data and near filed data has been achieved.Finally,the simulation experiment of Matlab point target imaging is carried out in accordance with the fast imaging algorithm proposed in this dissertation.The simulation results show that the imaging algorithm proposed in this dissertation can enable far field data and near filed data to realize fast focusing effectively.(2)To date studies on deformation monitoring based on the GB-InSAR system is not common in China,and most of them are still on the stage of laboratorial simulation or purchasing ready-made products from abroad to carry out feasibility verification.Although the GB-InSAR device made in foreign countries is relatively advanced in terms of technology,it costs much.For example,a common IBIS-L device made by the IDS Company is priced at one million Yuan.As a result,it’s hard to popularize this kind of device.Based on this,the author has tried to put forward a small-size and low-power GB-InSAR system.The concrete realization plan of the system is presented in Chapter V in a detailed manner,which includes RF front-end channel design,acquisition and processing of base-band signals,construction of systematic physical construction and methods of synthetic apertures.Moreover,a variety of parameters are presented,the Max.Measuring distance is given according to the radar equation.After that,the deformation monitoring experiment is carried out later by virtue of the GB-InSAR system designed in this dissertation,which has tested and verified the effectiveness of transformation monitoring by applying this system. |
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