Evaluation of the Clutter Mitigation Decision Performance as a Function of Clutter to Signal Ratio

The Clutter Mitigation Decision (CMD) algorithm has been developed to detect the presence of significant ground clutter echoes. Subsequently a clutter filter is applied to those radar resolution volumes where clutter is present and the radar moments computed from this selectively clutter filtered data. In this way zero velocity weather echoes are preserved while clutter echoes are mitigated. The single polarization version of the CMD was deployed on the National Weather Service network of operational Weather Surveillance Radar 1988 Doppler (WSR-88D) radars and the dual-polarimetric version of CMD is planned to be implemented after the dual-polarimetric upgrade.

It is important to identify and remove ground clutter even when it is mixed with stronger weather signal. This is because clutter at weak Clutter to Signal Ratio (CSR) values have been shown to contaminate dual-polarimetric variables. A rigorous test for CMD is to overlay time-series I and Q radar scan from a known pure weather case with a known pure clutter case. Care must be taken to make sure that the clutter scan does not contain any clear-air echo power and the weather scan does not contain any clutter echo power. Also the system noise will be doubled by adding the signals together and must be accounted for to obtain accurate CSR estimates. Once the clutter and weather signals are overlaid and accurate CSR estimates made it is straightforward to apply CMD and determine the percentage of clutter identifications as a function of CSR.

This presentation will describe how the time-series scans were chosen to be overlaid to ensure accurate CSR estimates and present the results of the CMD performance evaluation as a function of CSR.