Robert Davis Freeman

US Patent:

45367647, Aug 20, 1985

Filed:

Sep 29, 1982

Appl. No.:

6/427332

Inventors:

Robert D. Freeman - Severna Park MD

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

G01S 1352
G01S 728

US Classification:

343 5SA

Abstract:

A method of analyzing the doppler spectrum obtained from narrow band doppler filtering in the post-detection processing of a radar for the purposes of counting multiple targets moving in close proximity to one another is disclosed. More specifically, a set of contiguous doppler frequency signals is selected from the computed doppler frequency spectrum of a range gate of a radar look for establishing the target count thereof. The selected doppler frequency signals are processed in two passes with each pass including the steps of searching, threshold detection, and target counting. A pass count is established for each pass. The pass counts are combined in a predetermined count algorithm to establish a final count of the range gate being processed. Moreover, a selected group of contiguous range gates may be selected to establish a cumulative or total final count of targets in a selected portion of the range of a radar look. The established final counts of the selected range gates are combined in a cumulative count algorithm which takes into consideration range gate signal quality and the avoidance of multiple countings of a common target which may straddle adjacent range gates.