Techniques for improving ground clutter identification

Several radar parameters quantifying signal variability in single-polarisation radar measurements (Power Ratio, PR; Clutter Phase Alignment, CPA; and Absolute Power Difference, APD) are evaluated using Bayes‟ theorem in terms of the separation between the returns from ground clutter and precipitation. As these parameters are not independent, the intention is to identify the parameter providing the best separation. It is shown that either PR or CPA, in combination with a radial measure of texture of reflectivity (in dBZ), provides excellent separation of ground clutter and precipitation returns on a gate-by-gate basis. The demonstrated skill in clutter identification is comparable to that only previously reported using dualpolarisation measurements. This approach is well-suited for anomalous propagation as clutter maps are not used. The findings suggest that ground clutter identification is likely to benefit from measurements of PR or CPA even when dual-polarisation parameters are available.