Research On Deformation Monitoring Technology Based On Ground Based Synthetic Aperture Radar

Recently，many large engineering structures such as long span bridge, dam electricityand skyscraper have been built，which play an portatant influence on the production and lifeof humans.However, these large-scale structures may occur deformation when they are used,especially in disaster environment.When the deformations exceed their safe ranges, theywill result in disastrous consequences.So it is nessesary to excute deformation monitoringon them.Deformation monitoring is not only the primary means for risk warning in advance,but also the major method for ananlysis of buiding deformation mechanism.Therefore, this paper studies a system and method of deformation monitoring ofground based synthetic-bandwidth synthetic aperture radar.The synthetic aperturetechnology is used to improve the azimuth resolution,and the synthetic bandwidthtechnology is used to improve the range resolution, and the interferometric technology isused to get the displacement. Radar radiates multiple sub-band signals to the observationarea and receives the echo signals.The echo signals are processed as follows based onRange Doppler Algorithm of synthetic aperture radar imaging algorithm: process thesesub-band signals firstly by each matched filter, and then finish the range compression of theultra width radar signal by coherent synthesis of these sub-band signals, and then executerange correction and azimuth compression to get the image of the observation area.Thispaper also analyzes the basic principle of synthetic bandwidth signal processing,takinglinear frequency modulated signal as subband signal and stepped frequency signal asinterband signal for example. The paper also discusses each stage of radar signal processingand the relationship of various parameters of non-full aperture imaging radar system withthe limited conditions of ground environment and track length. Theoretical analysis andsimulation results show that this method can achieve the range resolution of0.1m andazimuth resolution of0.4m, and the millimeter level accuracy of displacementmeasurement.Compared with the conventional ground-based synthetic aperture radar, this systemhas better performance of range resolution by introducing the synthetic wideband signalprocessing technology.