An Experimental Evaluation of Phase Coding to Mitigate the Cross-Coupling Biases in PPAR

The Spectrum Efficient National Surveillance Radar (SENSR) program is exploring the feasibility of combining the functions of multiple national aircraft and weather surveillance radar networks into a single network of polarimetric phased array radar (PPAR) systems. One of the main challenges on this path is the use of PPAR for weather observations. In planar PPAR, this is due to the fact that the array copolar and cross-polar patterns vary with beam steering resulting in significant cross coupling between the horizontal (H) and vertical (V) channels. One proposed cross coupling mitigation technique is a 180° pulse-to-pulse phase change of signals injected in either the H or V ports of the transmission elements. Herein, this technique is evaluated using a ten-panel dual-polarization phased-array mobile demonstration system (referred to as the Ten Panel Demonstrator or TPD). This system has been developed by the MIT Lincoln Laboratory and is operated by the National Severe Storms Laboratory (NSSL).