Utilizing Versatile Transmission Waveforms to Mitigate Pulse-Compression Range Sidelobes With the HIWRAP Radar

The NASA Goddard Space Flight Center (GSFC) High-altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) is a solid-state dual frequency Doppler radar funded by the NASA Instrument Incubator Program. It uses direct-digital-synthesizer devices to generate versatile waveforms including conventional pulses and linear frequency modulation (LFM) chirps. This letter describes a waveform used by the GSFC and the Remote Sensing Solutions to address the critical limitations of range sidelobes and blind ranges in airborne pulse-compression radar. By utilizing a frequency diversity waveform consisting of two pulses and an LFM chirp at each transmit cycle, this system provides the improved sensitivity and range resolution benefits of pulse compression on targets within the middle and high altitudes while maintaining conventional pulsed data near the radar and the surface. The data obtained by the HIWRAP during the NASA Midlatitude Continental Convective Clouds Experiment using this waveform scheme are presented.