A Method Study Of The Data Processing And Observing For Severe Convection By Phased Array Weather Radar

In order to evaluate the radar performance and data quality of phased array radar in the outfield experiment, and provide authentic consequence for quality control, equipment improvement and convective storm research. In this paper, we used phased array radar equation for reflectivity correction, then studied the data processing, quantitative comparison, and convective weather analysis. The main research and preliminary results of this thesis are as follows:(1) Based on the classic meteorological radar equation and array antenna structure, we developed the radar equation for vehicle-borne S band one-dimensional phased array radar, air-borne X band planar phased array radar, vehicle-borne X band one-dimensional phased array radar, which applied in reflectivity correction. The verified results indicate that the modified radar equation could revise reflectivity bias caused by the variation of beam width and antenna gain.(2) According to the experimental requirement of phased array weather radar, a reflectivity matching algorithm, a wide beam smoothing algorithm and a quantitative analysis method focusing on various radar resolution in different places are proposed. Observation data in different locations can be matched very well with the proposed algorithm, precipitation structure, minimum reflectivity factor, scatter diagram, probability diagram, radial and vertical profile were also used in quantitative analysis. And vertical smoothing algorithm based on sampling volume could achieve the best results.(3) Using the matching algorithm in the observational data of vehicle-borne S band one-dimensional phased array radar and Nanjing CINRAD 54km away, the precipitation structure and its value measured by the two radars are compared. Results indicate that phased array radar can make precipitation measurements with reasonable accuracy, but at the range of 100 km, the smearing effect and velocity bias caused by the wide beam width is obvious. Because of the weaker sensitivity, this phased array weather radar can hardly detect the subtle structures.(4) The air-borne X band planar phased array radar was tested in July and August 2012, and observational data from operational X-band Doppler radar at the same site and the CINRAD 51 km away were also used to examine the work mode of phased array radar. The pulse compression of this radar could improve its sensitivity effectively while introducing calibration bias of 4.6 dB, and the main cause for the radar detecting ability is the wide transmitted beam. Results provide references for radar debugging and aircraft experiment.(5) The vehicle-borne X band one-dimensional phased array radar and C band polarization radar were installed at the same site in 2013, the dependability of 3 kinds of work mode with different beam width was verified. The source of phased array radar reflectivity bias comes from the antenna parameters difference, and the measurement deviation could be decreased within 1 dB through the statistics of stable rainfall process. By the comparison from precipitation structures, the space-time resolution of phased array radar is significant superiorly in the convective weather detection.(6) Through the evaluation of scanning strategy from vehicle-borne X band one-dimensional phased array radar during 2013, we found the time consuming of radar observation is too long, which caused by the intensive beam distribution. The optimal algorithm for elevation layer and beam position could get enough spatial resolution and limit the observation time, and makes scanning strategy more flexible in the future field experiment.