The Technical Research Of Frequency Domain Filter And Dual PRF Data Processing Of The New Generation’s Doppler Weather Radar

The Doppler weather radar-based data mainly by meteorological echoes andground clutter, excessive ground clutter will be a serious pollution of base data.Because all the products(such as reflectivity products,velocity products,etc) and thecomplex meteorological algorithms are based on the base data of Doppler weatherradar, if we do not suppress the ground clutter will not only damage the base data,butalso damage the base products.Therefore, Doppler weather radar want to get thehigh-quality base data and products must be suppressed ground clutter.Doppler weather radars can detects the location and reflectivity intensity of thereal weather target(such as the precipitation cloud system etc) by the echo data of thereal weather target. The dynamic range of the real weather targets can exceed75dB,and the average velocity of typhoons and other extreme weather will be greater than25m/s, so the weather radars are required with the large range-velocity range,otherwise will appear range-velocity ambiguity. The range-velocity ambiguity willalso seriously affect the Doppler weather radar data to generate high-quality products,so the solution fuzzy processing is very important to improve the quality of theDoppler weather radar data.Firstly, this dissertation introduces the research background, purpose andsignificance of ground clutter suppression and the resolution of range-velocityambiguity, analyzes the causes of super-refraction echoes, ground clutter andrange-velocity ambiguity, and introduces some methods of inhibition.Secondly, this dissertation talks about how to use the frequency-domainfiltering techniques to improve the quality of the Doppler weather radar data. Firstintroduced the time-domain filtering techniques originally used by the Dopplerweather radar, Gives the basic theory of the time-domain filtering and the designmethod of the IIR elliptic filter, and analysis the ground clutter suppression of IIRelliptic filter. And then explored the frequency-domain filtering techniques. Giventhe basic theory of the frequency-domain filtering techniques, Focus on adaptiveGaussian frequency-domain filter. Introduces the adaptive Gaussian frequency-domain filter’s characteristics and the application of the premise of thesuppression of clutter. Used the radar echo signal to analysis the ground cluttersuppression of the adaptive Gaussian frequency-domain filter, and were comparedwith the ground clutter suppression of IIR elliptic filter.Thirdly, this dissertation talks about the dual PRF techniques. Gives the basictheory of the dual PRF techniques, Focus on the dual PRF velocity formula and theresolution of range-velocity ambiguity by the dual PRF techniques. Used the actualacquisition of the radar echo signal to analysis and compare the dual PRF technologyto the single PRF technology.In the end, all quality control experimental results were compared in thisdissertation. In ground clutter suppression, adaptive Gaussian frequency-domainfilter performance better than the IIR elliptic filter. In the resolution of range-velocityambiguity, the dual PRF technology to replace the single PRF technology isundoubtedly the trend of the times.