Information gathering using reflected satellite signals

• US 7,564,402 B2
• Filed: 07/22/2005
• Issued: 07/21/2009
• Est. Priority Date: 07/26/2004
• Status: Active Grant

• Current Assignee: Drexel University
• Original Assignee: Drexel University
• Inventors: Einstein, Bruce A.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Nguyen; Nga X
• Application Number:
  US11/187,133
• Publication Number:
  US 20060077094A1
• Time in Patent Office: 1,460 Days
• Field of Search: 342/357.06, 342/357.15, 342/353, 455/65
• US Class Current: 342/357.31
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems

Abstract

A method of using reflected satellite signals, such as GPS signals or high orbit satellite signals, to determine information including the steps of: receiving direct and reflected satellite signals from the same satellite at one or more receivers, comparing a power of said reflected satellite signal with a power of the direct satellite signal from the same satellite to obtain a ratio, comparing the ratio to at least one calibrated ratio obtained from calibration data; and determining information from a result of said step of comparing said ratios. The method is useful for the purpose of determining information about the presence or absence of an object, person or animal, the volume of motor vehicle or foot traffic, the aridity of land, monitoring an area for intruders, monitoring parking lots and enhancing security systems.

Claims

1. A method of using reflected satellite signals to determine information comprising the steps of:

receiving one or more reflected satellite signals from at least one satellite at one or more receivers, said reflected satellite signals being reflected from an object, ground or a combination thereof, prior to reception by said one or more receivers;

determining a power of said one or more reflected satellite signals;

comparing the determined power of said one or more reflected satellite signals to a calibrated value of a power obtained from calibration data for said object, said ground or said combination thereof; and

determining information about said object, said ground, or an area or a location as a result of said comparing step.

2. The method of using reflected satellite signals as set forth in claim 1, wherein said determined information is selected from the group consisting of:

traffic volume, aridity of land, a presence or absence of an object, person or animal, topographical features of land, and a number of objects, persons or animals.

3. The method of using reflected satellite signals as set forth in claim 1, further comprising the step of taking an action based on said determined information.

4. The method of using reflected satellite signals as set forth in claim 3, wherein said action is selected from the group consisting of:

providing a notification, activating an alarm, transmitting information, and activating a watering system.

5. The method of using reflected satellite signals as set forth in claim 1, further comprising the step of modifying said calibration data using data obtained from one or more of said reflected satellite signals.

6. The method as claimed in claim 5, wherein said step of modifying said calibration data comprises the steps of obtaining information from said data obtained from one or more of said reflected satellite signals, processing said data, and adjusting a result determinative value obtained from said calibration data based on said information obtained from one or more of said reflected satellite signals.

7. The method as claimed in claim 1, wherein said method is employed to determine the presence or absence of an object, person or animal.

8. The method of using reflected satellite signals as set forth in claim 1, wherein said reflected satellite signal is from a high orbit satellite.

9. The method of using reflected satellite signals as set forth in claim 1, wherein said reflected satellite signal is from a low orbit satellite.

10. The method of using reflected satellite signals as set forth in claim 1, wherein said calibration data accounts for weather effects on reflectivity of said reflected signal.

11. The method as set forth in claim 1, wherein said method determines information about the speed of movement of, or tracks, one or more of an object, a person and an animal.

12. The method of using reflected satellite signals as set forth in claim 1, wherein said information is transmitted to a remote location by a form of transmission selected from the group consisting of a cellular transmission, a satellite transmission and a wireless transmission.

13. The method as set forth in claim 1, further comprising the step of comparing a determined Doppler shift of said one or more reflected satellite signals to at least one calibrated value of a Doppler shift obtained from calibration data for said at least one object, said ground or said combination thereof and determining a velocity or movement of said at least one object, as a result of said comparing step.

21. The method as set forth in claim 1, further comprising the step of comparing a determined phase of said one or more reflected satellite signals to at least one calibrated value of a phase obtained from calibration data for said at least one object, said ground or said combination thereof and determining a velocity or movement of said at least one object, as a result of said comparing step.

14. A method for processing satellite signals to determine information comprising the steps of:

receiving a reflected satellite signal at one or more receivers, wherein said reflected satellite signal is reflected from an object, ground or a combination thereof prior to being received at said one or more receivers;

comparing a power of said reflected satellite signal to a calibrated value of a power representing said object, said ground or said combination thereof; and

determining information about said object, said ground, an area or a location as a result of said comparison step.

15. The method as set forth in claim 14, further comprising the step of modifying said calibration data based on data selected from the group consisting of data obtained from one or more of said reflected satellite signals and data regarding the effects of weather on said reflected satellite signals.

16. The method as set forth in claim 14, further comprising the step of taking an action based on said determined information.

17. The method as set forth in claim 16, wherein said action is selected from the group consisting of:

providing a notification, activating an alarm, transmitting information, and activating a watering system.

18. The method as set forth in claim 14, wherein said method determines information about the speed of movement of, or tracks, one or more of an object, a person and an animal.

19. The method as set forth in claim 14, wherein said method captures an image of, or determines a presence or absence of one or more of an object, a person and an animal.

20. The method as set forth in claim 14, wherein said receivers process a reflected satellite signal selected from the group consisting of an optical signal, a microwave signal, a radar signal and an ultrasound signal.