7.4: A Polar-Coordinate Real-Time Three-Dimensional Rapidly Updating Merger Technique for Phased Array Radar Scanning Strategies

The National Weather Radar Testbed (NWRT) phased array radar will not be operated in fixed volume coverage patterns. Instead, the phased array radar will attempt to simultaneously maximize the utility of several possible uses, such as 3D storm analysis, area surveillance and aircraft tracking. In order to do so, the phased array radar will employ adaptive scanning and intersperse meteorological scans with aircraft tracking. To a downstream visualization program or automated severe-weather detection algorithm operating on phased array radar data, the incoming stream will be randomly organized in space and time. It is up to the application to create a coherent view of the atmosphere from the phased array radar beams. In this paper, we describe a method of creating such a coherent view. In polar coordinates, this involves creating a rapidly updated ”virtual volume scan”. The virtual volume scan is created by treating each of the phased array radar range gates as ”intelligent agents” that place themselves in the resulting polar grid, know how to collaborate with other agents to create optimal estimates of the radar values at each range gate of the virtual volume and know when they have either been superseded or are too old. The resulting virtual volume, created in real-time, is used by the downstream applications. This enables the downstream applications to work with a regularly spaced grid that is created at periodic intervals.