Phased-array radar applications

Evolutionary Scanning Strategies for Phased-Array Radars

Pulsed weather radars continuously sample the atmosphere in three dimensions, and scanning strategies are used to control how this sampling occurs. The effective design of scanning strategies involves tailoring spatial sampling and data acquisition parameters for a specific need or particular meteorological situation. In a 2011 paper, we discuss the considerations and tradeoffs involved in the design of scanning strategies.

For the PARISE experiments, we have adopted phenomenon-specific scanning strategies. These achieve the best tradeoffs for a particular situation. Improved spatial resolution is achieved with scanning strategies employing higher-resolution vertical sampling and/or azimuthal sampling. Unique to the PAR is that the inherent beam broadening that occurs as the beam is electronically steered away from boresite can be exploited to reduce the number of beam positions and obtain faster updates. For improved temporal resolution there are different options. Beam multiplexing (BMX) can be exploited to produce good data quality with faster updates. The tradeoff is in terms of data quality since effective ground clutter filters that are compatible with BMX have yet to be developed. More frequent updates for the lowest tilt are achievable by adding a low-elevation scan half way through the scanning strategy. This results in good data quality, but faster updates are only realized at the lowest tilt and this leads to slightly slower updates elsewhere. Through elevation-prioritized scanning different updates at different levels can be achieved. In general, the fastest updates occur at the lowest tilts for the best temporal resolution closer to the ground. Intermediate tilts are updated less frequently, enough to detect new storm developments with short latency. Finally, the upper tilts get the slowest updates. Another way to improve the temporal resolution of the NWRT PAR without loss in data quality is to scan less than the full 90°. However, new developments outside the reduced sector are likely to be missed. An optimum compromise to produce good-quality data with faster updates is to employ adaptive scanning techniques that automatically focus data collection on smaller areas of interest at the same time that periodic surveillance is performed to capture new storm developments.

The PARISE project's official webpage is here.

A nice overview of the NWRT PAR capabilities for rapid scanning can be found on this paper.

Back to PAR applications