US Patent 7417578 Removal of spurious aircraft detections on weather radar

A weather radar detects and removes spurious aircraft from a weather radar display by using one of the methods of differentiating radar return length, estimating a vertical gradient of reflectivity, tracking radar returns into regions that are eliminated from the weather display to provide differentiation, tracking areas of radar returns that allow detection and removal of the spurious aircraft in relative geometries, differentiating Doppler velocity, and differentiating spectral width. The methods may be used individually or in combination to improve performance.