Accession Number : ADA207504

Title :   Efficient Dealiasing of Doppler Velocities Using Local Environmental Constraints,

Corporate Author : NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION NORMAN OK NATIONAL SEVERE STO RMS LAB

Personal Author(s) : Ellis, Michael D ; Smith, Steven D

PDF Url : ADA207504

Report Date : Jan 1989

Pagination or Media Count : 45

Abstract : A Doppler velocity dealiasing algorithm is described that processes one radial at a time by comparing that radial with a previous radial. This technique has worked reliably on numerous Doppler radar data sets for clear air, thunderstorm, and sever thunderstorm situations. It was also tested on four volume scans from severe weather environments with difficult aliasing problems to determine statistically how well the algorithm performs in a worst case environment. Of some 1.2 million velocities in these severe storms, 0.2% were improperly dealiased, and 93% of those were above 13 km height in the storm-top divergent region where shears were extreme. Every tornado, mesocyclone, gust front, microburst and storm-top divergent signature was preserved, and could be identified by automated algorithms. This algorithm is adaptive and therefore efficient because simple checks are made initially, and progressively more sophisticated and time-consuming checks are used only if they are needed. Keywords: Doppler radar; Velocity; Microburst; Algorithm; Wind shear. (jhd)

Descriptors :   *ALGORITHMS, *DOPPLER RADAR, *SIGNAL PROCESSING, *DATA REDUCTION, CLEAR AIR TURBULENCE, AUTOMATION, DATA BASES, DOPPLER SYSTEMS, HIGH RATE, INTENSITY, SCANNING, STORMS, THUNDERSTORMS, VELOCITY, VOLUME, WIND SHEAR

Subject Categories : Active & Passive Radar Detection & Equipment
      Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE