Coding and Beam Multiplexing for Phased Array Radar

Herein we address quick volume scans and requirements on polarimetric performance of phased array weather radar, the two top challenges for this promising technology. A consensus is emerging that alternate transmission and reception of H and V polarized waves could provide good quality polarimetric variables for limited range of radar variables, but further enhancements of that mode are needed to match all the current capability of the polarimetric WSR-88D. If the simultaneous mode of transmission could offer equally good polarimetric performance it would be the natural choice as it has a proven and thus far an unmatched track record in operational applications. There are two antenna designs that in ideal conditions should produce adequate polarimetric performance of the simultaneous mode. None of these have been tested. We discuss coding schemes that could be applied to attenuate the cross polar component in the simultaneous mode. For speeding volume coverage a sub pulse beam multiplexing is suggested. Its effectiveness increases if coding within the pulse is applied. Coding also offers selective reduction of signal powers from ambiguous range intervals and as well an increase in volumetric scan rates. Trade offs and issues imposed on pulse coding for these multiple purposes are presented.