In spring 2009, the NOAA National Severe Storms Laboratory implemented a basic, electronic adaptive scanning algorithm, ADAPTS (Adaptive Digital Signal Processing Algorithm for PAR Timely Scans), on the National Weather Radar Testbed Phased-array Radar (NWRT PAR). The primary goal of ADAPTS is to improve scan time by focusing sampling on significant weather targets. For a given scanning strategy, beam positions are turned “on” or “off” based on three criteria. These criteria and their associated thresholds were chosen to ensure that: 1) lower elevation angles are always scanned, 2) at higher elevation angles only significant weather returns are sampled, and 3) “on” beam-positions account for storm growth, decay, and advection. Though limited preliminary testing suggested that these criteria accomplished these goals, a more thorough analysis of their impact on weather sampling and update time is needed.

In this study, ADAPTS's performance is examined by assessing the weather sampling and time savings resulting from implementation of the three criteria. Based on this assessment, the three criteria are refined and sensitivity tests on threshold values run to determine impacts on ADAPTS performance. Performance improvements resulting from the sensitivity studies are illustrated for a few weather events, and remaining limitations are discussed.