Method of compensating for atmospheric effects while using near horizon radar

• US 6,833,805 B1
• Filed: 02/20/2003
• Issued: 12/21/2004
• Est. Priority Date: 02/20/2002
• Status: Expired due to Fees

• Current Assignee: University Corporation For Atmospheric Research
• Original Assignee: University Corporation For Atmospheric Research, Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Holder, Ernest Jefferson, Dugas, Susan Ferebee, Belenʼkii, Mikhail S.
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US10/370,258
• Time in Patent Office: 670 Days
• Field of Search: 342/26, 342/54, 342/148, 342/159, 342/162, 342/179, 342/180, 342/195, 342/357.06, 342/357.08, 342/460
• US Class Current: 342/26.00D
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 7/4004 of parts of a radar system

Abstract

A method of compensating for atmospheric effects to detect the actual location of low elevation objects using near horizon radar to detect an object which utilizes a preexisting satellite, wherein the location of the satellite is known. The method includes a step of providing a radar site, a first receiver structured to receive a signal from the satellite, and known location data for the satellite then positioning the first receiver near the radar site. The first receiver is utilized to receive a signal from the satellite when the satellite is at a low elevation. The bending angle can then be determined by comparing the apparent location data of the satellite as determined by the first receiver to the known location data of the satellite. This data may also be combined with weather data is used to determine a three dimensional refractivity model. Once the bending angle of the atmosphere is determined, the radar is used to detect the apparent location data of a low elevation object. The location of the low elevation object can then be determined by applying the bending angle to the apparent location data of the object.

Claims

1. A method of compensating for atmospheric effects while using near horizon radar to detect an object, said method utilizing a preexisting satellite wherein the location of the satellite is known, said method comprising the steps of:

a) providing a radar site, a first receiver structured to receive a signal from said satellite, and known location data for said satellite;

b) positioning said first receiver near said radar site;

c) utilizing said first receiver to receive a signal from said satellite when said satellite is at a low elevation, said signal indicating the apparent location data of said satellite;

d) determining the bending angle of the atmosphere by comparing the apparent location data of said satellite as determined by said first receiver to the known location data of the satellite;

e) using the radar site to detect the apparent location data of a low elevation object; and

f) determining the location of the low elevation object by applying the bending angle to the apparent location data of the object.

2. The method of claim 1, wherein data representing the known location data of said satellite is maintained in a remote database and said step of providing said known location data includes the step of acquiring the known location data through a communication medium.

3. The method of claim 1, wherein said satellite is a GPS satellite.

4. The method of claim 1, wherein said step of determining the bending angle includes the step of creating a three-dimensional bending angle model.

5. A method of compensating for atmospheric effects while using near horizon radar to detect an object, said method utilizing a preexisting satellite wherein the location of the satellite is known, said method comprising the steps of:

a) providing a radar site, a first receiver structured to receive a signal from said satellite, known location data for said satellite and weather data;

b) positioning said first receiver near said radar site;

c) utilizing said first receiver to receive a signal from said satellite when said satellite is at a low elevation, said signal indicating the apparent location data of said satellite;

d) creating a three-dimensional refractivity field based on said weather data;

e) determining the bending angle of the atmosphere by utilizing said three dimensional refractivity field and comparing the apparent location data of said satellite as determined by said first receiver to the known location data of the satellite;

f) using the radar site to detect the apparent location data of a low elevation object; and

g) determining the location of the low elevation object by applying the bending angle to the apparent location data of the object.

6. The method of claim 5, wherein data representing the known location data of said satellite is maintained in a remote database and said step of providing said known location data includes the step of acquiring the known location data through a communication medium.

7. The method of claim 5, wherein global weather data is maintained in a remote database and said step of providing said weather data includes the step of acquiring the global weather data through a communication medium.

8. The method of claim 7, wherein:

said radar site includes a weather station; and

said step of providing said weather data includes the step of acquiring local weather data from said weather station.

9. The method of claim 5, wherein:

said radar site includes a weather station; and

said step of providing said weather data includes the step of acquiring local weather data from said weather station.

10. The method of claim 5, wherein said satellite is a GPS satellite.

11. A method of compensating for atmospheric effects while using near horizon radar to detect an object, said method utilizing a preexisting satellite, said method comprising the steps of:

a) providing a radar site, a first receiver structured to receive a signal from said satellite, and, a second receiver structured to receive a signal from said satellite;

b) positioning said first receiver near said radar site;

c) positioning said second receiver at a distance from the radar site;

d) utilizing said first receiver to receive a signal from said satellite when said satellite is at a low elevation relative to said radar site, said signal indicating the apparent location data of said satellite, while simultaneously utilizing said second receiver to receive a signal from said satellite when said satellite is at a high elevation relative to said second receiver, said signal indicating the observed location data of said satellite;

e) determining the bending angle of the atmosphere by comparing the apparent location data of said satellite as determined by said first receiver to the observed location data of said satellite as determined by said second receiver;

f) using the radar site to detect the apparent location data of a low elevation object; and

g) determining the location of the low elevation object by applying the bending angle to the apparent location data of the object.

12. The method of claim 11, wherein data representing the known location data of said satellite is maintained in a remote database and said method includes the further steps of:

a) providing said satellite known location data; and

b) including said known location data in said step of determining said bending angle.

13. The method of claim 12, wherein said step of providing said satellite known location data includes the step of acquiring the known location data through a communication medium.

14. The method of claim 11, wherein said satellite is a GPS satellite.

15. The method of claim 11, wherein said step of determining the bending angle includes the step of creating a three-dimensional refractivity field model.

16. A method of compensating for atmospheric effects while using near horizon radar to detect an object, said method utilizing a preexisting satellite, said method comprising the steps of:

a) providing a radar site, a first receiver structured to receive a signal from said satellite, a second receiver structured to receive a signal from said satellite, and weather data;

b) positioning said first receiver near said radar site;

c) positioning said second receiver at a distance from the radar site;

d) utilizing said first receiver to receive a signal from said satellite when said satellite is at a low elevation relative to said radar site, said signal indicating the apparent location data of said satellite, while simultaneously utilizing said second receiver to receive a signal from said satellite when said satellite is at a high elevation relative to said second receiver, said signal indicating the observed location data of said satellite;

e) creating a three-dimensional refractivity field model based on said weather data;

f) determining the bending angle of the atmosphere by utilizing said three dimensional refractivity field model and comparing the apparent location data of said satellite as determined by said first receiver to the observed location data of the satellite as determined by the second receiver;

g) using the radar site to detect the apparent location data of a low elevation object; and

h) determining the location of the low elevation object by applying the bending angle to the apparent location data of the object.

17. The method of claim 16, wherein data representing the known location data of said satellite is maintained in a remote database and said method includes the further steps of:

a) providing said satellite known location data; and

b) including said known location data in said step of determining said bending angle.

18. The method of claim 17, wherein said step of providing said satellite known location data includes the step of acquiring the known location data through a communication medium.

19. The method of claim 16, wherein global weather data is maintained in a remote database and said step of providing said weather data includes the step of acquiring the global weather data through a communication medium.

20. The method of claim 19, wherein:

said radar site includes a weather station; and

said step of providing said weather data includes the step of acquiring local weather data from said weather station.

21. The method of claim 16, wherein:

said radar site includes a weather station; and

said step of providing said weather data includes the step of acquiring local weather data from said weather station.

22. The method of claim 16, wherein said satellite is a GPS satellite.

23. A method of determining the bending angle of the atmosphere, said method utilizing a preexisting satellite wherein the location of the satellite is known, said method comprising the steps of:

a) providing a first receiver structured to receive a signal from said satellite, and known location data for said satellite;

b) utilizing said first receiver to receive a signal from said satellite when said satellite is at a low elevation, said signal indicating the apparent location data of said satellite; and

c) determining the bending angle of the atmosphere by comparing the apparent location data of said satellite as determined by said first receiver to the known location data of the satellite.

24. The method of claim 23, wherein data representing the known location data of said satellite is maintained in a remote database and said step of providing said known location data includes the step of acquiring the known location data through a communication medium.

25. The method of claim 23, wherein said satellite is a GPS satellite.

26. The method of claim 23, wherein said step of determining the bending angle includes the step of creating a three-dimensional refractivity field model.

27. A method of determining the bending angle of the atmosphere, said method utilizing a preexisting satellite wherein the location of the satellite is known, said method comprising the steps of:

a) providing a first receiver structured to receive a signal from said satellite, known location data for said satellite and weather data;

b) utilizing said first receiver to receive a signal from said satellite when said satellite is at a low elevation, said signal indicating the apparent location data of said satellite;

c) creating a three dimensional refractivity field based on said weather data; and

d) determining the bending angle of the atmosphere by utilizing said three dimensional refractivity field and comparing the apparent location data of said satellite as determined by said first receiver to the known location data of the satellite.

28. The method of claim 27, wherein data representing the known location data of said satellite is maintained in a remote database and said step of providing said known location data includes the step of acquiring the known location data through a communication medium.

29. The method of claim 27, wherein global weather data is maintained in a remote database and said step of providing said weather data includes the step of acquiring the global weather data through a communication medium.

30. The method of claim 29, wherein said step of providing said weather data includes the step of providing a weather station near said first receiver and acquiring local weather data from said weather station.

31. The method of claim 27, wherein said step of providing said weather data includes the step of providing a weather station near said first receiver and acquiring local weather data from said weather station.

32. The method of claim 27, wherein said satellite is a GPS satellite.

33. A method of determining the bending angle of the atmosphere, said method utilizing a preexisting satellite, said method comprising the steps of:

a) providing a first receiver structured to receive a signal from said satellite, and, a second receiver structured to receive a signal from said satellite;

b) positioning said second receiver at a distance from said first receiver;

c) utilizing said first receiver to receive a signal from said satellite when said satellite is at a low elevation relative to said first receiver, said signal indicating the apparent location data of said satellite, while simultaneously utilizing said second receiver to receive a signal from said satellite when said satellite is at a high elevation relative to said second receiver, said signal indicating the observed location data of said satellite; and

d) determining the bending angle of the atmosphere by comparing the apparent location data of said satellite as determined by said first receiver to the observed location data of said satellite as determined by said second receiver.

34. The method of claim 33, wherein data representing the known location data of said satellite is maintained in a remote database and said method includes the further steps of:

a) providing said satellite known location data; and

b) including said known location data in said step of determining said bending angle.

35. The method of claim 34, wherein said step of providing said satellite known location data includes the step of acquiring the known location data through a communication medium.

36. The method of claim 33, wherein said satellite is a GPS satellite.

37. The method of claim 33, wherein said step of determining the bending angle includes the step of creating a three-dimensional refractivity field model.

38. A method of determining the bending angle of the atmosphere, said method utilizing a preexisting satellite, said method comprising the steps of:

a) providing a first receiver structured to receive a signal from said satellite, a second receiver structured to receive a signal from said satellite, and weather data;

b) positioning said second receiver at a distance from said first receiver;

c) utilizing said first receiver to receive a signal from said satellite when said satellite is at a low elevation relative to said first receiver, said signal indicating the apparent location data of said satellite, while simultaneously utilizing said second receiver to receive a signal from said satellite when said satellite is at a high elevation relative to said second receiver, said signal indicating the observed location data of said satellite;

d) creating a three dimensional refractivity field model based on said weather data; and

e) determining the bending angle of the atmosphere by utilizing said three dimensional refractivity field model and comparing the apparent location data of said satellite as determined by said first receiver to the observed location data of the satellite as determined by the second receiver.

39. The method of claim 38, wherein data representing the known location data of said satellite is maintained in a remote database and said method includes the further step of providing said known location data through a communication medium.

40. The method of claim 38, wherein global weather data is maintained in a remote database and said step of providing said weather data includes the step of acquiring the global weather data through a communication medium.

41. The method of claim 40, wherein said step of providing said weather data includes the step of providing a weather station near said first receiver and acquiring local weather data from said weather station.

42. The method of claim 38, wherein said step of providing said weather data includes the step of providing a weather station near said first receiver and acquiring local weather data from said weather station.

43. The method of claim 38, wherein said satellite is a GPS satellite.