System and technique for mitigation of clutter in radar

Patent metadata

Field	Value
Publication number	US-10955524-B2
Application number	US-201715820617-A
Country	US
Kind code	B2
Filing date	Nov 22, 2017
Priority date	Nov 22, 2016
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Described are a system and technique to mitigate the impacts of clutter in a radar system. The system and technique require only linear co-polarized measurements can be incorporated into the standard radar signal processing chain without slowing down radar performance.

First claim

What is claimed is:

1. A method for clutter mitigation in a radar system capable of producing detections using RF signals having two orthogonal polarizations, the method comprising:
processing sets of radar return pulses in each of a first polarization and a second, associated orthogonal polarization to form processed signals, with each set of radar return pulses including one or more pulses;
performing detections on each processed signal to form a detection set, the detections corresponding to potential targets;
associating pairs of detections across the first and second polarizations; and
monitoring displacement of the associated pairs of detections across the first and second polarizations across a sequence of sets of radar return pulses.

2. The method of claim 1 further comprising identifying associated pairs of detections that move with respect to each other over time.

3. The method of claim 2 further comprising removing from the detection set those associated pairs of detections that move at different rates of speed with respect to each other over time.

4. The method of claim 3 further comprising processing those associated pairs of detections that do not move with respect to each other over time to track an object.

5. The method of claim 3 wherein identifying associated pairs of detections that move with respect to each other over time comprises identifying associated pairs of detections that move apart over time as false alarms due to clutter.

6. A method for clutter mitigation in a radar system capable of producing detections using RF signals having two orthogonal polarizations, the method comprising:
processing sets of radar return pulses in each of a first polarization and a second, associated orthogonal polarization to form processed signals, with each set of radar return pulses including one or more pulses;
performing detections on each processed signal to form a detection set;
associating pairs of detections across the first and second polarizations; and
monitoring displacement of the associated pairs of detections across the first and second polarizations across a sequence of sets of radar return pulses,
wherein processing sets of radar return pulses in each of a first polarization and a second, associated orthogonal polarization includes averaging sets of radar return pulses in each of the first polarization and the second, associated orthogonal polarization to form averaged signals, and
wherein performing detections on each processed signal to form a detection set includes performing detections on each averaged signal to form a detection set.

7. A method for mitigating sea clutter in a marine radar system capable of producing detections using RF signals having two orthogonal polarizations (H-H and (V-V), the method comprising:
processing pulses in a CPI in each of HH and VV to form averaged signals;
performing CFAR detection on each averaged signal;
associating pairs of CFAR detections across H-H and V-V; and
monitoring displacement of the associated pairs of CFAR detections across H-H and V-V across a sequence of CPIs.

8. The method of claim 7 further comprising identifying associated pairs of CFAR detections that move apart over time.

9. The method of claim 8 further comprising filtering out of a detection set those associated pairs of CFAR detections that move apart over time.

10. The method of claim 9 identifying those associated pairs of CFAR detections that move apart over time as false alarms due to sea clutter.

11. The method of claim 10 further comprising providing to a radar tracker those associated pairs of CFAR detections that do not move apart over time.

12. The method of claim 6 further comprising identifying associated pairs of detections that move with respect to each other over time.

13. The method of claim 12 further comprising removing from the detection set those associated pairs of detections that move at different rates of speed with respect to each other over time.

14. The method of claim 13 further comprising processing those associated pairs of detections that do not move with respect to each other over time to track an object.

15. The method of claim 13 wherein identifying associated pairs of detections that move with respect to each other over time comprises identifying associated pairs of detections that move apart over time as false alarms due to clutter.

Assignees

• Massachusetts Inst Technology

Inventors

• Crane Molly K
• Mooradd David C

Classifications

• G01S7/025 Primary

  involving the transmission of linearly polarised waves · CPC title

• G01S2013/0227

  OTH, Over-The-Horizon radar · CPC title

• G01S13/5248

  combining a coherent MTI processor with a zero Doppler processing channel and a clutter mapped memory, e.g. MTD (Moving target detector), (area MTI G01S13/538) · CPC title

• G01S13/5246

  post processors for coherent MTI discriminators, e.g. residue cancellers, CFAR after Doppler filters · CPC title

• G01S7/2923

  based on data belonging to a number of consecutive radar periods · CPC title