Doppler Weather Radar Research and Development
NSSL Project 7 – Investigation of Advancements in Radar Technology toward the Improvement of Hazardous Weather Detection and Warnings:
Mitigation of Range and Velocity Ambiguities
Funding Type: CIMMS Task II
Objectives
Resolve WSR-88D range and Doppler velocity ambiguities to the levels required
for the efficient observation of severe weather, culminating in significantly
improved WSR-88D data quality when implemented on the Open Radar Data
Acquisition (ORDA) sub-system – the increased data quality will
result in an improved ability for the WSR-88D to detect severe weather,
flash floods, winter storms, and provide aviation forecasts.
Accomplishments
Over the past decade, two techniques have emerged as viable candidates
to address the mitigation of range and velocity ambiguities in the
WSR-88D, thus reducing the amount of purple haze obscuration currently
encountered during the observation of severe phenomena. These are:
1) systematic phase coding (SZ-2) and 2) staggered pulse repetition
time (SPRT). The two techniques are complementary since they offer
advantages at specific elevation angles; hence, they can be simultaneously
incorporated into the same volume coverage pattern (VCP).
One of this year’s major accomplishments was the NEXRAD Software Recommendation and Evaluation Committee’s (SREC) official approval of the SZ-2 algorithm for inclusion in the next build of ORDA. This was the result of successful technology transfer to the ROC. The second stage of NEXRAD upgrades dealing with range and velocity ambiguities involves the operational implementation of SPRT. During this year, we focused on designing operational VCPs using SPRT and on evaluating the performance of a novel ground clutter filter that operate on staggered samples.
This project is ongoing.
Publications
Torres, S., 2006: Range and velocity ambiguity mitigation on the WSR-88D:
Performance of the staggered PRT algorithm. 22nd
International Conf. on Interactive Information and Processing Systems
(IIPS) for Meteorology, Oceanography, and Hydrology, Atlanta, GA, Amer. Meteor. Soc., CD-ROM
9.9.
Saxion, D. S., R. D. Rhoton, R. L. Ice, D. A. Warde, O. E. Boydstun, S. M. Torres, G. Meymaris, and W. D. Zittel, 2007: New science for the WSR-88D: Implementing a major mode on the SIGMET RVP8. Preprints, 23rd International Conference on Interactive Information and Processing Systems (IIPS) for Meteorology, Oceanography, and Hydrology, San Antonio, TX, Amer. Meteor. Soc., P2.9.
Volume Coverage Pattern (VCP) for NEXRAD range and velocity ambiguity mitigation. Systematic phase coding (SZ- 2) is employed at the lower elevation angles and staggered pulse repetition time (SPRT) at the intermediate elevation angles.