A Demonstration of a Scanning Multiple Antenna UHF Radar

The cross-beam component of wind is not easy to directly measure on scanning radar. It is often estimated using tracking or modeling techniques which involve steady state and/or many other assumptions, or by using two radars in dual Doppler analysis. Some vertically pointing radars, such as NCAR's MAPR (Multiple Antenna Profiler Radar) 915MHz wind profiler, use spaced antenna techniques to directly measure the cross beam wind velocity. MAPR has four closely spaced receiving antennas and is usually used for fast vertical profiling of fronts, waves, bores, rotors, and other rapidly evolving events. In the current experiment, MAPR was tilted on its side, temporarily mounted on a pedestal and slowly scanned in the azimuthal direction to test the application of spaced antenna and interferometry techniques to scanning radar. Several localized storms were observed and comparisons were made with nearby soundings, surface instruments, a (vertically pointing) wind profiler, and a sodar. Although there were limitations such as a wide beam and limited range, the radar did prove to be a useful platform for testing wind measuring techniques. The presentation will outline the experiment, discuss the feasibility and application of the technique, and give examples of the observations.