Research On Broadband Displacement Measurement Radar Technology

When large buildings are used, especially be used in the disaster environment, it will be deformed. Deformation monitoring technology can be used to monitor the occurrence and development of building deformation in real time. It can make an early warning of possible risks. A kind of micro displacement monitoring technique is proposed in the patent "a micro displacement measurement system", this is a kind of microwave radar measurement technology with the advantage of high measuring accuracy and less affected by climate. This method measures the displacement of the corner reflector by measuring the carrier phase of the microwave phase device and the angular reflector. This is a single-frequency continuous wave radar. The disadvantage is that the dense distribution of passive corner reflectors can not be distinguished. Multi point displacement measurement can not be realized. It is the key technology to solve the multi point displacement measurement system that how to realize the resolution and separation of multi angular reflectors in the sight of radar line.It can be known by the radar principle that the range resolution of radar is inversely proportional to the bandwidth of the transmitted signal. Therefore, high resolution can be obtained by transmitting an ultra wide band signal. Due to the constraints of technical and hardware costs, the realization of ultra wide band signal has become the focus and difficulty by the researchers in the field of radar. With the development of broadband technology research around the world, Synthetic broadband technology arises at the historic moment. The broadband signals obtained through the synthesis not only overcome the technical and cost problems, but also the resolution of the imaging of the target is the same as that of the ideal ultra wideband signal.Based on this, in this paper, a method for measuring the displacement based on the wideband radar is proposed. Radar transmit Multi band signal, the subband is a linear frequency modulation signal, among which is the step frequency signal. The echo signal is matched filter processing, frequency domain splicing, IDFT processing and coherent combination to obtain the high resolution. Making a Phase interference measurement for two distance images, displacement of each corner reflector in line of sight can be measured. The simulation program of the Matlab software is used to simulate the deformation monitoring system of the wideband radar in this paper. The simulation results prove that the feasibility and rationality of the theoretical analysis, which can also obtain a high range resolution. This method can not only avoid the disadvantage of the conventional wideband waveform application. At the same time, it can make up for the shortcomings of the existing displacement measurement system, which has a strong engineering application value.