Research Of Ambiguity Problem In Pulse Doppler Weather Radars

Pulse Doppler weather radars can not only detect the location and intensitydistribution of rain, but also detect the motion characteristics of hydrometeorsaccording to Doppler information contained in weather echo. This is very importantto the research of the forming of precipitation, the analysis of the micro-scaleweather system, and the forecasting of strong convection weather phenomenon. Thedynamic range of weather targets is very large, and the mean velocity of strongstorms weather is about50m/s, so the weather radars are required with the largerange-velocity range, otherwise there will appear range-velocity ambiguity.Firstly, we introduce the development of the weather radar and the basic principle ofweather targets detect and the problem of range—velocity ambiguity. Then, we discuss thetime and frequency domain properties of weather radar echo, methods of weatherradar echo spectral moments estimators in the time and frequency domain, weatherradar echo simulation methods and relativity. Secondly,we introduce the ambiguityresolution of staggered repetition frequency and then put my mind on the study ofthe staggered repetition frequency ambiguity resolution，in the end give the formulaof velocity estimate and restricts condition and method of modify.The simulationresults show that the modified formula could reduce the error in the range of themost non-ambiguity of velocity.Then, we studied on the staggered PRT algorithms and the phase-codingalgorithms on the mitigating of range-velocity ambiguity. The staggered PRTalgorithms and the SZ(8/64) phase-coding algorithms are realized on a weatherradar to investigate the performance of these two algorithms. In the end of thisarticle, we give the preliminary results collected with the weather radarexperimental results demonstrate the ability of SZ(8/64) phase coding and thestaggered PRT to effectively mitigate range-velocity ambiguity.