Minimum Variance Distortionless Response based Distributed Beamforming Technique for C-Band Weather Radar

Distributed Beamforming (DB) technique in phased array radars is a technique that offers significant advantages over mechanically steered narrow-beam weather radars, in terms of scan rate or optimized polarimetric measurement variance. In this study, a simulation-based investigation has been conducted to analyze the variance reduction (in azimuth angle scan) of radar-estimated reflectivity and differential reflectivity using the DB technique. This DB technique uses the minimum variance distortion-less response (MVDR) method for individual beamforming. The In-phase/Quadrature (I/Q) signals used in the beamforming have been simulated from the reflectivity and differential reflectivity observed by CSU-CHIVO C-band radar deployed and operated during the RELAMPAGO field experiment. The main challenge of the study is to simulate a spoiled transmit beam that is $12^{o}$ wide in real-time and then use digital beamforming to generate multiple simultaneous receive beams that are $4^{o}$ wide because of the application of the DB technique the estimated reflectivity standard deviation reduced by 5 dB while the differential reflectivity reduced by 0.5 dB. The results of the simulation-based study showed that using the distributed beamforming technique with MVDR led to a significant improvement in the variance of reflectivity and differential reflectivity measurements.