Using Simulation to Find Pulsing Schemes that Meet Requirements for Airborne Polarimetric Doppler Phased Array Weather Radar

A novel, advanced atmospheric system, the Airborne Phased Array Radar (APAR), is currently being developed at NCAR. APAR will operate using electronic beam steering with 4 C-band Active Electronically Scanned Arrays (AESAs): one on each aircraft side, one on top, and one on the bottom. The typical scanning strategy will be to have three scans for each cycle: 1) Doppler 2) dual-polarization and 3) surveillance, which, because of the aircraft's airspeed, will all need to be completed in about 2.5 seconds. Achieving the moment estimator statistical performance goals while meeting the desired angular resolution and sensitivity in less than 2.5 seconds is particularly challenging. One confounding aspect is that different moments perform better under different pulsing schemes. For example, radar reflectivity performance is improved by increasing the number of independent samples, whereas differential radar reflectivity is improved by having correlated samples. These lead to two very different optimal pulsing schemes. Indeed, each moment performs best under different pulsing schemes, creating a challenge to identify several pulsing schemes that balance all of the moment estimator idiosyncrasies. In this presentation, we will discuss using an in-phase and quadrature-phase (I/Q) simulator to help find pulsing schemes that meet the desired requirements.