Design And Implementation Of Signal Processing System Of Multifunctional Low-altitude Three-dimensional Radar

Under the background of low-altitude airspace reform management in our country, the low-altitude airspace will be opened gradually, together with more various of low-altitude and ultra-low altitude flying tasks. But the small-scale meteorological disaster sometimes happened under 3kilometers low-altitude airspace, which has greatly threatened the safety of low-altitude aircrafts. So besides of the monitoring and management of aircrafts, we still need to monitor the meteorological environment in low-altitude airspace, for which we could design a specialized low-altitude blind compensated meteorological radar, which will greatly increase the equipment input and the life-cycle cost however, together with the mutual radiated interference getting worse, besides it is not worth paying to deploy in small-size general aviation airports. However, the multifunctional low-altitude surveillance radar can meet the demand, which has many advantages such as flexible beam directivity and various of scanning modes. This pager starts from two aspects of radar target surveillance signal processing and meteorological observation signal processing. Based on the research of the key arithmetic in signal processing and the compatibility between the two kinds of work mode, we study the multifunctional low-altitude surveillance radar directed at the research of radar signal processing system designing and problems existed in engineering implementation process together with methods to solve these problems. We finished the designing of some key links of software and hardware of this signal processing system, and validated the system already. This paper is structured as follows:Firstly, we analyzed the key arithmetic of signal processing abouttwo work modes of target surveillance and meteorological observation of multifunctional low-altitude three-dimensional radar. Mainly include digital phase demodulation processing ? digital pulse compression processing ? adaptive active interference suppression ? adaptive clutter jamming suppression?signal detection processing?angle measurement processing? target plot-track recording in target surveillance mode, and noise power estimation ? clutter suppression ? spectral estimation in meteorological observation mode and so on. We studied about the realizing ways based on research of algorithms, and proposed one kind of radar scheduling mode that compatible with target surveillance and meteorological observation, and preliminarily solved two contradiction in different gradations, which are compatibility between observation of target and meteorology, and compatibility between reflectivity factor and Doppler parameter estimation.Secondly, we analyzed and calculated the main work parameters of signal processing system based on the algorithm research. It is designed to input the actual application environment and system index of multifunctional low-altitude three- dimensional radar, and take some model structure and data simulation on DDC?pulse compression?MTI?MTD?CFAR?meteorological signal processing clutter suppression and meteorological base data threshold-cross processing by using Matlab simulation tools, according to which we set related parameters and calculate work parameters so that to provide designing basis to system engineering implementation.Lastly, we made some engineering design and system verification to software and hardware of the signal processing system. We detailed analyzed the main difficulty and key technology of realizing radar signal processing by FPGA based on algorithm and system index research, and put forward a kind of general signal processing hardware platform architecture that was suitable for the system, and made a detailed designing scheme about this platform. In the aspect of system software implement-tation, we built a radar signal processing modular library on the basis of reconfigurable IP core technology, combined with radar signal processing IP core designing process at first. And then, we put forward the software process of signal processing system on the demand of system requirement,and introduced the overall design of system software in detail included by logic partitioning criterion?soft structure scheme and data transmission between FPGA and so on, meanwhile, the FPGA source usage of radar signal processing system would be present. We also discussed the test system and test method about signal processing, and analyzed the test results and performance in the process of system verification.