Optimizing Radiation Patterns for Weather Observations through a Cylindrical Polarimetric Phased Array Radar

The mechanically rotating weather surveillance radar (WSR-88D) requires about five minutes to perform a complete 360^o scan. It is desirable for the national weather radar network to provide accurate multi-parameter measurements with fast data update because currently, the operational radar systems are not efficient enough to reliably observe severe weather phenomena. To achieve this goal, the concept of cylindrical polarimetric phased array radar (CPPAR) has been proposed to electronically scan the volume and provide a rapid data update compared to conventional mechanical scan radar systems. Each CPPAR beam is formed from a 90° degree sector of the cylindrical antenna array, and azimuthal beam steering is achieved by commuting the set of excited antennas columns around the cylinder. A modified particle swarm optimization is presented to optimize the beamforming weights in order to reach a multifunctional radar system for accurate weather measurements with low sidelobe levels and highly matched co-polarization patterns for all commuted beams in azimuth. The performance improvements are demonstrated by applying the proposed optimized radiation patterns to the CPPAR and compared the CPPAR weather observations data with an operational WSR-88D (KTLX) polarimetric weather radar.