Patent · US Expired

Constant false alarm rate with low probability of false alarms

US5038145A · kind A · utility

169Cited by
2References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 20, 1989
Grant dateAug 6, 1991
Priority date
Expiry dateNov 20, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S7/2922
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A constant false alarm rate (CFAR) circuit uses three windows for calculating mean level thresholds. In addition to a lead window and a lag window each separated from a cell of interest by a predetermined number of cells, a straddle window is used which includes the cell of interest. Each of the lead, lag and straddle windows are subjected to editing to remove three adjacent cells including the cell with the highest power level. The remaining cells are used to calculate a mean level threshold for each of the three windows. The largest of the three mean level thresholds is used, unless it is derived from the straddle window and it is significantly larger than the largest of the mean level thresholds derived from the lead and lag windows. In addition, use of the mean level threshold derived from the straddle window may be excluded for range cells associated with one or more range and azimuth.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.