A Pulse Compression Waveform for Improved-Sensitivity Weather Radar Observations

Abstract

The progression of phased array weather observations, research, and planning over the past decade has 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 weather radar technology includes the use of active arrays, where each element would have its own transmit/receive module. This would lead to significant advantages; however, such a design must be capable of utilizing low-power, solid-state transmitters at each element in order to keep costs down. To provide acceptable sensitivity, as well as the range resolution needed for weather observations, pulse compression strategies are required. Pulse compression has been used for decades in military applications, but it has yet to be applied on a broad scale to weather radar, partly because of concerns regarding sensitivity loss caused by pulse windowing. A robust optimization technique for pulse compression waveforms with minimalistic windowing using a genetic algorithm is presented. A continuous nonlinear frequency-modulated waveform that takes into account transmitter distortion is shown, both in theory and in practical use scenarios. Measured pulses and weather observations from the Advanced Radar Research Center’s dual-polarized PX-1000 transportable radar, which utilizes dual 100-W 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.

Observations of a Cold Front at High Spatiotemporal Resolution Using an X-Band Phased Array Imaging Radar

“…In order to increase sensitivity, a 'high sensitivity' mode was designed for the AIR based on the method described in [55]. As opposed to the standard 5.25 µs waveform used by the AIR for studies of severe local storms [56], a 13.25 µs pulse was developed for use on transmit.…”

A frequency-sharing weather radar network system using pulse compression and sidelobe suppression

“…(B) Contiguous deployment of weather targets leads to an overlap between autocorrelation sidelobes of adjacent targets, which vastly distorts the MF output even with the code of low autocorrelation sidelobe. For this reason, a pulse compression radar system dealing with weather targets [16] has focused on addressing the distortion from autocorrelation sidelobe.…”

A Pulse Compression Waveform for Weather Radars With Solid-State Transmitters

“…Based on some empirical analysis and results [3], [12], [14], the t−ω curve should be monotonic so that the waveform has good range sidelobe performance, which indicates that dt/dω > 0 or dt/dω < 0. Without loss of generality, in the rest of this letter, we assume that dt/dω > 0 so that | • | in (4) can be dropped.…”

“…Thus, their designed NLFM waveforms have limited performance on the range sidelobe level and Doppler tolerance. To enhance the waveform performance, recently, new techniques, such as computer optimization [12], have been introduced to exploit the potential of NLFM waveforms. This letter differs from both the original analytical model using the combination of linear and known nonlinear functions and the method based on pure computer optimization.…”