Impulse radar security system

• US 6,518,915 B2
• Filed: 11/13/2001
• Issued: 02/11/2003
• Est. Priority Date: 11/15/2000
• Status: Active Grant

• Current Assignee: Geophysical Survey Systems, Inc.
• Original Assignee: Geophysical Survey Systems, Inc.
• Inventors: Johnson, Dennis, Schutz, Alan
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US10/013,751
• Publication Number:
  US 20020109624A1
• Time in Patent Office: 455 Days
• Field of Search: 342/27, 342/28, 342/107, 342/108, 342/109, 342/114, 340/541, 340/545.3, 340/554, 340/565, 340/567, 340/552
• US Class Current: 342/28
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/18 wherein range gates are used
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 13/888 through wall detection
• CPC Class Codes: G01S 7/4004 of parts of a radar system
• CPC Class Codes: G08B 13/187 by interference of a radiation field
• CPC Class Codes: G08B 13/2494 by interference with electro-magnetic field distribution combined with other electrical sensor means, e.g. microwave detectors combined with other sensor means

Abstract

The present invention provides a security system that can provide a user with data on the directional movement, velocity and location of an object within and around the perimeter of a structure with the use of radio energy. The system comprises a sensor unit having at least one antenna for transmission of a signal into a defined area of the structure. Any intrusion in the area is detected upon a change in the waveform received by the antenna. A received signal is transmitted from the sensor unit to a control unit, comprising, in part, a preprogrammed data processing unit that can determine the movement of the intruder. Utilization of a plurality of sensor units allows the user to obtain additional information on the velocity and location of the intruder. Additionally, as with conventional security systems, the system can provide an electrical signal to activate a sound and/or light device to attract the attention of the intruder and warn others of the intruder'"'"'s presence.

Claims

1. A radar security system for a residential or commercial structure, comprising:

a) a sensor unit electrically connected to at least one antenna for, generation and transmission of at least one first signal and receipt of at least one reflected second signal, said sensor unit comprises a sample-hold circuit for sampling said at least one second signal, wherein said at least one second signal comprises a plurality of reflected signals at a sequence of points in a waveform of said at least second signal for generating at least one sampled signal having a substantially identical amplitude as said at least one second signal and a lower frequency than said at least one second signal allowing for efficient data processing;

b) a control unit comprising a read-only memory (ROM) for storage of an algorithm used in conversion of said at least one sampled signal to a third signal comprising an average waveform obtained over a specified time interval, said control unit electrically connected to said sensor unit through a linking element for comparing said at least one sampled signal to said third signal and generating a fourth signal indicative of a parameter of interest upon determination of a deviation between said at least one sampled signal and said third signal; and

c) a display device electrically connected to said control unit for receiving. said fourth signal and displaying said parameter of interest.

2. The radar security system of claim 1, wherein said control unit further comprises a random-access memory (RAM) for storage of said third signal.

3. The radar security system of claim 1, wherein said sensor unit further comprises a time-variable range amplifier providing signal gain proportional to an average signal loss in transmission of said at least one first signal and receipt of said at least one second signal.

4. The radar security system of claim 1, wherein said sensor unit further comprises a range window filter providing for the acceptance of signals representative of a moving object over a specified time interval and rejection of signals representative of a stationary object over said specified time interval.

5. The radar security system of claim 1, wherein said at least one first signal is one of:

(i) an ultra wide band signal within the radio spectrum;

(ii) a wide band signal within the radio spectrum;

(iii) a swept continuous wave signal within the radio spectrum;

(iv) a stepped continuous wave signal within the radio spectrum; and

(v) a coded pulse train signal within the radio spectrum.

6. The radar security system of claim 1 further comprising a transmit/receive switch for electrically separating said at least one first signal and said at least one second signal wherein said at least one antenna comprises a single antenna.

7. The radar security system of claim 6, wherein said transmit/receive switch comprises at least one diode.

8. The radar security system of claim 6, wherein said transmit/receive switch comprises at least one field-effect transistor.

9. The radar security system of claim 1, wherein said display device is a three-dimensional wire-frame display.

10. The radar security system of claim 1 further comprising a sound device electrically connected to said control unit for receiving said fourth signal and producing a sound in response to said fourth signal.

11. The radar security system of claim 1 further comprising a light device electrically connected to said control unit for receiving said fourth signal, and illuminating said light device in response to said fourth signal.

12. The radar security system of claim 1 further comprising a time delay device to allow a user to initialize the system without prematurely activating the system.

13. The radar security system of claim 1 wherein the link element is one of (i) a coaxial cable;

(ii) a wire link;

(iii) an optical fiber;

(iv) a radio link;

(v) an infrared link; and

(vi) an ultrasound link.

14. The radar security system of claim 1 wherein the parameter of interest is one of (i) directional movement of an object;

(ii) velocity of said object; and

(iii) position of said object.

15. A method of processing a signal in a radar security system having a single, sensor unit, comprising:

(a) transmitting at least one first signal from an antenna into a predefined area;

(b) receiving at least one reflected second signal at said antenna;

(c) sampling said at least one second signal, wherein said at least one second signal comprises a plurality of reflected signals at a sequence of points in a waveform of said at least one second signal for generation of at least one low frequency signal proportional to said at least one second signal with a sample-hold circuit;

(d) amplifying said at least one low frequency signal proportional to an average signal loss with a time-variable range amplifier thereby providing nominal signal levels equal over a range of interest;

(e) comparing said at least one low frequency signal to a third signal representative of an average waveform of said at least one low frequency signal over a specified time interval stored in memory in a control unit in determining if there is any deviation between said third signal and said at least one low frequency signal thereby establishing physical movement within said predefined area and generating a fourth signal; and

(f) transmitting said fourth signal from said control unit to a display device to display a parameter of interest of (i) directional movement of an object;

(ii) velocity of said object; and

(iii) position of said object.

16. A method of processing a signal in a radar security system having multiple sensor units, comprising:

(a) defining an area to be monitored by the radar security system;

(b) identifying the location of each of the sensor units and storing the location into a memory of a control unit;

(c) transmitting at least one first signal from at least one antenna into a predefined area;

(d) receiving at least one reflected second signal at said at least one antenna;

(e) sampling said at least one second signal, wherein said at least one second signal comprises a plurality of reflected signals at a sequence of points in a waveform of said at least one second signal for generation of at least one low frequency signal proportional to said at least one second signal with a sample-hold circuit;

(f) amplifying said at least one low frequency signal proportional to the average signal loss with a time-variable range amplifier thereby providing nominal signal levels equal over a range of interest;

(g) comparing said at least one low frequency signal to a third signal representative of an average waveform of said at least one low frequency signal over a specified period of time stored in memory in a control unit in determining if there is any deviation between said third signal and said at least one low frequency signal thereby establishing physical movement within said predefined area and generating a fourth signal;

(h) tracking and identifying said at least one second signal; and

(i) transmitting said fourth signal from said control unit to a display device to display a parameter of interest of (i) directional movement of an object;

(ii) velocity of said object; and

(iii) position of said object.