Example of clutter suppression exhibited by the CLEAN-AP© filter. Note that the filter provides over 60 dB of clutter suppression without biasing the weather signal power estimate. To place this into context, the filter easily provides the clutter suppression requirements of 50 dB required for operations in the U.S. network of weather surveillance radars (i.e., the NEXRAD network of WSR-88D radars). Image courtesy of D. Warde.
A common dilemma in obtaining quality meteorological-variable estimates using Doppler weather radar is the application (or misapplication) of ground clutter filters (GCF) to mitigate contamination from ground returns. Typically, weather radars use static clutter maps (i.e., pre-identified clutter contaminated regions) to control the application of the GCF. Ideally, the GCF should only be applied if the ground clutter contamination obscures the weather estimate. However, the problem of applying the GCF becomes very complex considering the dynamic atmospheric effects on radar beam propagation. The goal of this project is to develop efficient techniques that provide both automated detection and application of ground clutter filtering.
Recently, we suggested a spectral technique for automatic detection and mitigation of ground clutter contamination: the Clutter Environment Analysis using Adaptive Processing (CLEAN-AP©) filter. We have shown the clutter detection and mitigation performance of the CLEAN-AP© filter using time-series data from the National Weather Radar Testbed Phased-Array Radar (NWRT PAR), the national network of weather surveillance radars (WSR-88D), and the University of Oklahoma's OU-Prime radar . Compared to current technologies used for ground clutter suppression, the CLEAN-AP© filter provides a real-time, integrated clutter mitigation solution with:
In March of 2011, the NEXRAD Technical Advisory Commitee approved CLEAN-AP for an engineering evaluation on the WSR-88D. In the near future, our plan is to enhance the detection capabilties of CLEAN-AP© by using polarimetric information available from this system. In addition, we have extended this filter to work with staggered PRT sequences.
For more details about CLEAN-AP©, follow this link to get a copy of the paper that we presented at the 2009 AMS Radar Conference in Williamsburg, VA . Comparisons between CLEAN-AP© and the current ground clutter mitigation scheme on the WSR-88D were presented in a paper at the 2010 AMS Annual Meeting. In addition, we have filed an Invention Disclosure with The University of Oklahoma Intellectual Property Office; the non-confidential details about this technique can be found in this document.
Our latest report to the NWS Radar Operations Center documents the work that resulted in the endorsement of CLEAN-AP by the NEXRAD Technical Advisory Committee.
We recently received a second award from the National Science Foundation (NSF) for our research project "Understanding the Relationship Between Tornadoes and Debris Through Observed and Simulated Radar Data."
This fall, I had the honor and privilege to teach an OLLI class with my friend and colleague Jami Boettcher. "NEXRAD Weather Radar: How it Works and What Those Images Tell Us" kept us busy for 5 weeks this fall.
Our paper "Bootstrap Dual-Polarimetric Spectral Density Estimator" made the cover of the April 2017 issue of the IEEE Transactions on Geoscience and Remote Sensing journal.
I have accepted to serve as an associate editor for the American Meteorological Society’s Journal of Atmospheric and Oceanic Technology.
I have been chosen as the winner of the 2016 OU College of Atmospheric and Geographic Sciences Dean’s Award for Outstanding Service.