Polarized millimeter wave imaging system and method

Patent metadata

Field	Value
Publication number	US-9330330-B2
Application number	US-201414156095-A
Country	US
Kind code	B2
Filing date	Jan 15, 2014
Priority date	Jan 15, 2014
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A detection system includes a polarization analyzer that generates one or more null detection values if an object is sensed in a received millimeter wave (MMW) brightness temperature data set. The polarization analyzer analyzes a polarization parameter in the received MMW brightness temperature data set to generate the one or more null detection values. An object detector detects if the object is present based on a comparison of the one or more null detection values to a predetermined threshold. A singular value decomposition (SVD) unit is enabled by the object detector to decompose the MMW brightness temperature data set into a plurality of image layers. Each image layer includes at least one feature of a scene. An identification unit analyzes the plurality of image layers from the SVD unit to determine a shape or a location of the object from the scene.

First claim

What is claimed is:

1. A detection system, comprising:
a polarization analyzer that generates one or more null detection values if an object is sensed in a received millimeter wave (MMW) brightness temperature data set, wherein the polarization analyzer analyzes a polarization parameter in the received MMW radiation data set to generate the one or more null detection values; and
an object detector that detects if the object is present based on a comparison of the one or more null detection values to a predetermined threshold.

2. The detection system of claim 1 , wherein the object is an explosive formed penetrator (EFP).

3. The detection system of claim 1 , wherein the polarization parameter includes polarization difference that is defined by Δ hv =T h −T v , where T h and T v are the horizontal and vertical brightness temperature components of the MMW brightness temperature data set acquired at a given observation angle θ, or includes a polarization index that is defined by δ hv =(T h −T v )/(T h +T v ) at the given observation angle.

4. The detection system of claim 3 , wherein a temperature average T avg is employed by the polarization analyzer to detect contrast between cold sky temperature reflected from the metallic object and warm background terrain.

5. The detection system of claim 3 , wherein a temperature average T avg is employed by the polarization analyzer to detect contrast between cold sky temperature reflected from the metallic object and warm background terrain.

6. The detection system of claim 1 , further comprising a singular value decomposition (SVD) unit to decompose the MMW radiation data set into a plurality of image layers, wherein each image layer includes at least one feature of a scene that includes background noise, background clutter, ground debris, or the object.

7. The detection system of claim 6 , wherein the SVD unit generates a filtered image by summing the plurality of image layers.

8. The detection system of claim 7 , wherein the SVD unit generates a moment image for each of the plurality of image layers to facilitate a determination of an intensity or a position of the object.

9. The detection system of claim 8 , further comprising an identification unit to identify the position of the object based on an analysis of the plurality of images or the moment image for each of the plurality of image layers.

10. The detection system of claim 1 , further comprising a polarized MMW radiometer to generate the MMW radiation data set.

11. The detection system of claim 10 , wherein the polarized MMW radiometer includes a linear antenna array to scan in an x, y, and z dimension and is mounted on a mobile platform.

12. The detection system of claim 11 , wherein the linear antenna array generates a pushbroom fan beam that scans in the y and z dimensions and the x dimension is covered by motion of the mobile platform.

13. A detection system, comprising:
a polarization analyzer that generates one or more null detection values if an object is sensed in a received millimeter wave (MMW) brightness temperature data set, wherein the polarization analyzer analyzes a polarization parameter in the received MMW brightness temperature data set to generate the one or more null detection values;
an object detector that detects if the object is present based on a comparison of the one or more null detection values to a predetermined threshold;
a singular value decomposition (SVD) unit that is enabled by the object detector to decompose the MMW brightness temperature data set into a plurality of image layers, wherein each image layer includes at least one feature of a scene; and
an identification unit that analyzes the plurality of image layers from the SVD unit to determine a shape or a location of the object from the scene.

14. The detection system of claim 13 , wherein the object is an explosive formed penetrator (EFP).

15. The detection system of claim 13 , wherein the polarization parameter includes a polarization difference that is defined by Δ hv =T h −T v , where T h and T v are the horizontal and vertical brightness temperature components of the MMW brightness temperature data set acquired at a given observation angle θ, or includes a polarization index that is defined by δ hv =(T h −T v )/(T h +T v ) at the given observation angle.

16. The detection system of claim 13 , wherein the SVD unit generates a filtered image by summing the plurality of image layers.

17. The detection system of claim 16 , wherein the SVD unit generates a moment image for each of the plurality of image layers to facilitate a determination of an intensity or a position of the metallic object.

18. The detection system of claim 13 , further comprising a polarized MMW radiometer to acquire the MMW brightness temperature data set.

19. A method, comprising:
generating, by a processor, one or more null detection values if an object is sensed in a received millimeter wave (MMW) brightness temperature data set, wherein the one or more null detection values are generated from a polarization parameter in the received MMW radiation data set;
detecting, by the processor, if the object is present based on a comparison of the one or more null detection values to a predetermined threshold;
decomposing, by the processor, the received MMW brightness temperature data set into a plurality of image layers, wherein each image layer includes at least one feature of a scene; and
analyzing, by the processor, the plurality of image layers to determine a shape or a location of the object from the scene.

20. The method of claim 19 , wherein the object is an explosive formed penetrator (EFP).

Assignees

• Karam Mostafa A
• Anderson Kent
• Shori Raj K
• Meyer A Douglas
• Northrop Grumman Systems Corp

Inventors

• Karam Mostafa A
• Anderson Kent
• Shori Raj K
• Meyer A Douglas

Classifications

• G06V20/80 Primary

  Recognising image objects characterised by unique random patterns · CPC title

• G06K9/00577

  Physics · mapped topic

• G01S7/499

  using polarisation effects · CPC title

• G01S13/89

  for mapping or imaging · CPC title

• G01J5/60

  using determination of colour temperature · CPC title