An Optimized Pulse Compression Waveform for High-Sensitivity Weather Radar Observations

The progression of phased array weather observations, research, and planning over the past decade have led to significant advances in development efforts for future weather radar technologies. However, numerous challenges still remain for large-scale deployment. The eventual goal for phased array antennas in the weather radar field includes the use of active arrays, meaning each element would be its own transmit/receive module. This advancement would lead to significant advantages, however such a design must be capable of utilizing low-powered, solid-state transmitters at each element in order to keep costs down. In order to provide acceptable sensitivity, as well as the range resolution needed for weather observations, pulse compression has been shown as a viable technique for implementation. Pulse compression has been used for decades in military applications, but is yet to be applied on a broad scale to weather radar, due in part to concerns regarding sensitivity loss. A broad, detailed optimization technique for pulse compression waveforms with minimalistic windowing using a genetic algorithm is presented. A continuous nonlinear frequency modulated waveform which takes into account transmitter distortion is shown, both in theory and in practical use scenarios. Actual point target and weather observations from the Advanced Radar Research Center's dual-polarized PX-1000 mobile radar, which utilizes dual 100-Watt solid-state transmitters, are presented. Both stratiform and convective scenarios, as well as dual-polarization observations, are shown, demonstrating significant improvement in sensitivity over previous pulse compression methods.