Evaluation of first generation CASA radar waveforms in the IP1 testbed

The Center for Collaborative Adaptive Sensing of the Atmosphere (CASA), an engineering research center (ERC) established by the National Science Foundation (NSF) deployed its first generation network of four low-power, short-range, X- band, dual-polarized Doppler weather radars known as NE- TRAD. The short range CASA radars will have range overlay and velocity folding problems with conventional pulse-pair processing. The first testbed of X-band radar systems (developed within the ERC) in central Oklahoma called IP-1 (Integrated Project 1) have a low unambiguous velocity due to their short wavelength, and increasing the PRF will result in multiple trip overlays since storms can extend over a large distance. In addition the radar observations at short ranges are contaminated by ground clutter. This paper describes the waveforms for the individual radar nodes based on NETRAD operational requirements such as scan speeds, volume coverage pattern and system/hardware limitations to resolve range and velocity ambiguities. A dual PRF waveform has been suggested for operational use based on a simulation study. This paper presents an evaluation of the waveform from data collected by the first generation CASA radars.