Combined radar and communications link

• US 7,633,426 B2
• Filed: 09/14/2004
• Issued: 12/15/2009
• Est. Priority Date: 01/20/2004
• Status: Expired due to Fees

• Current Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Original Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Inventors: Sutphin, Eldon M.
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US10/585,882
• Publication Number:
  US 20090135044A1
• Time in Patent Office: 1,918 Days
• Field of Search: 342/28, 342/22, 342/57, 342/58, 342/114, 340/541, 340/554
• US Class Current: 342/22
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 13/888 through wall detection
• CPC Class Codes: G01S 7/006 using shared front-end circuitry, e.g. antennas G01S13/765, G01S13/825 take precedence

Abstract

In a CW radar system for detecting motion behind a wall (12) involving modulation of the radar transmission, means (34) are provided to interrupt the CW wave when motion is detected and to use the same radar transmitter (30) to transmit a serial digital message to a remote monitoring receiver (34). The encoding can include a receiver wakeup message to turn on the receive only when motion has been detected. In one embodiment, a microprocessor (28) is used to detect when motion exists behind a wall and to provide a tailorable message to modulate the radar'"'"'s transmitter in the period when the CW signal from the radar is turned off after the motion detector.

Claims

1. A combined radar and communications link, comprising:

a radar having a frequency source and an antenna for forming a radar beam;

a unit at said radar for monitoring radar returns and for developing a signal reflecting a radar parameter;

means for interrupting the normal radar beam when the particular parameter has been detected; and

,

a modulator coupled to said frequency source and said signal reflecting a radar parameter for modulating the signal transmitted by said radar antenna after normal beam interruption in accordance with said parameter, whereby modulated radiation from said radar antenna establishes said communications link.

2. The combined radar and communications link of claim 1, wherein said parameter is associated with motion of an object in the beam of said radar and further including alerting means when the signal transmitted by said radar antenna is modulated.

3. The combined radar and communications link of claim 2, wherein said alerting means includes an audible signal generator.

4. The combined radar and communications link of claim 2, wherein said alerting means includes a display.

5. The combined radar and communications link of claim 4, wherein said display includes a visual representation of the position of the object relative to said radar.

6. The combined radar and communications link of claim 5, wherein said visual representation includes a plot of the position of said object.

7. The combined radar and communications link of claim 1, wherein said radar is a CW radar.

8. The combined radar and communications link of claim 7, wherein said parameter includes the motion of an object in the beam of said radar, and further including a detector for detecting the phase difference between the transmitted radar beam and the radar returns, said phase difference indicating the presence of a moving object in said radar beam.

9. The combined radar and communications link of claim 1, wherein said radar is a CW radar and wherein said modulation is selected from the group consisting of amplitude modulation, frequency modulation and phase modulation.

10. A method for providing covert security for an individual manning a radar, comprising the steps of:

locating an unmanned radar at a scene into which a radar beam is to be projected;

projecting the radar beam into the scene;

detecting returns from an object in the scene;

establishing a sensed parameter from the detected returns from the objects;

interrupting the normal radar beam in response to the occurrence of the sensed parameter;

turning on and modulating the radar beam in accordance with the sensed parameter so as to cause the radar antenna to emit modulated radiation; and

,

remotely sensing the modulated radiation, thus to obtain a remote indication of the results of the use of the radar, such that an individual can man the radar from a remote location, whereby the covertness and security of the individual is assured by using an inexpensive, efficient system that uses the same frequency source and antenna used by the radar in the communications link between the radar and the remote location.

11. The method of claim 10, wherein the radar is a CW radar and wherein the sensed parameter is movement of the object.

12. The method of claim 10, wherein the sensed parameter is the location of the object.

13. The method of claim 10, wherein the radar is used for through-the-wall location of objects behind the wall.

14. The method of claim 10, wherein the radar is used for surveillance.

15. The method of claim 10, wherein the radar is used for vehicle sensing.

16. The method of claim 10, wherein the radar is used for intrusion detection.