Multi channel radiometer imaging method and system

• US 20090041292A1
• Filed: 08/08/2007
• Published: 02/12/2009
• Est. Priority Date: 08/08/2007
• Status: Active Grant

• Current Assignee: Microsemi Corporation (Microchip Technology Incorporated)
• Original Assignee: Microsemi Corporation (Microchip Technology Incorporated)
• Inventors: Barrantes, Ernesto, Daly, Robert
• Granted Patent: US 8,213,672 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G01V 8/005 operating with millimetre waves, e.g. measuring the black losey radiation
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005

Abstract

The invention provides for an expandable multi channel radiometer imaging method and system. The imaging system includes a scanner for reflecting millimeter wave energy emanating from a pre-determined scene. The millimeter wave energy is focused to a focal plane array using an optical lens and a multi channel radiometer receives the millimeter wave energy. The focal plane array is formed by a plurality of pixels that each includes a single low noise amplifier. The number of pixels of the focal plane array is expendable to increase the resolution of a millimeter wave image. A virtual grid of cells is formed representing different values of millimeter wave energy within the imaging zone. Algorithms calculate differences of millimeter wave energy between cells of said virtual grid to display a composite image to identify concealed objects on an individual.

Claims

1. A method of detecting concealed objects on an individual comprising:

scanning an imaging zone of a scene for millimeter wave energy wherein the scanning apparatus having a reflective concave surface;

focusing the millimeter wave energy using an optical lens;

receiving the millimeter wave energy using a multi channel radiometer having a receiver;

calculating values for a grid of cells representing millimeter wave energy received by the multi channel radiometer;

analyzing differences between the values of the millimeter wave energy between the cells of said grid using algorithms;

identifying contrast cells from the grid of cells wherein the contrast cells having values of the millimeter wave energy with a preselected difference between adjacent cells;

forming a discrete image of contrast cells;

synchronizing the discrete image of contrast cells with a video image of the imaging zone;

forming a real-time composite image so that the imaging zone is overlaid with said discrete image of contrast cells; and

displaying said composite image.

2. The method of claim 1 further comprising providing a multi channel radiometer adaptable for electrically coupling a preselected number of RF boards having a plurality of pixels.

3. The method of claim 2 further comprising providing each pixel of the plurality of pixels with a single low noise amplifier

4. The method of claim 1 further comprising receiving millimeter wave energy between 80 and 100 GHz.

5. The method of claim 1 further comprising scanning the millimeter wave energy at four frames per second.

6. The method of claim 3 further comprising providing each pixel of the plurality of pixels with an RF switch coupled between an antennae and the receiver.

7. The method of claim 1 further comprising providing a multi channel radiometer with sixteen channels.

8. The method of claim 1 further comprising providing a multi channel radiometer with thirty-two channels.

9. The method of claim 1 further comprising synchronizing the discrete image of contrast cells with the video image of the imaging zone to within a preselected tolerance of fifty milliseconds at four frames per second.

10. An expandable multi channel radiometer imaging system for detecting concealed objects on an individual, the system comprising:

a scanning apparatus for scanning an imaging zone of a scene for millimeter wave energy wherein the scanning apparatus having a reflective concave surface;

an optical lens adaptable for focusing the millimeter wave energy,

a multi channel radiometer having a receiver for receiving the millimeter wave energy;

a means for calculating values for a grid of cells representing millimeter wave energy received by the multi channel radiometer;

means for analyzing differences between the values of the millimeter wave energy between the cells of said grid using algorithms;

means for recognizing and identifying contrast cells from the grid of cells wherein the contrast cells having values of the millimeter wave energy with a preselected difference between adjacent cells;

means for forming a discrete image of contrast cells;

means for synchronizing the discrete image of contrast cells with a video image of the imaging zone;

means for forming a real-time composite image so that the imaging zone is overlaid with said discrete image of contrast cells; and

means for displaying said composite image.

11. The multi channel radiometer of claim 10 adaptable for electrically coupling a preselected number of RF boards wherein the RF boards further comprise a plurality of pixels.

12. The pixels of claim 11 wherein each pixel of the plurality of pixels having a single low noise amplifier

13. The millimeter wave energy of claim 10 wherein the millimeter wave energy is between 80 and 100 GHz.

14. The scanning apparatus of claim 10 wherein the millimeter wave energy is scanned at four frames per second.

15. The pixels of claim 12 wherein each pixel of the plurality of pixels having an RF switch coupled between an antennae and the receiver.

16. The multi channel radiometer of claim 10 wherein the multi channel radiometer comprises sixteen channels.

17. The multi channel radiometer of claim 10 wherein the multi channel radiometer comprises thirty-two channels.

18. The means for synchronization of claim 10 wherein the synchronization of the discrete image of contrast cells with the video image of the imaging zone is to within a preselected tolerance of fifty milliseconds at four frames per second.

19. The system of claim 10 further comprising providing a central processing unit for synchronization the discrete image of contrast cells with the video image of the imaging zone.