Bi-static radar processing for ADS-B sensors

• US 8,130,135 B2
• Filed: 10/14/2009
• Issued: 03/06/2012
• Est. Priority Date: 10/14/2008
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Donovan, Timothy P.
• Primary Examiner(s): SOTOMAYOR, JOHN B
• Application Number:
  US12/578,861
• Publication Number:
  US 20100090882A1
• Time in Patent Office: 874 Days
• Field of Search: 342 29- 38, 342/46, 342/417
• US Class Current: 342/30
• CPC Class Codes: G01S 13/781 Secondary Surveillance Radar [SSR] in general
• 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: G08G 5/0078 for monitoring traffic from the aircraft radar or analogous systems specially adapted for traffic control G01S13/91
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933

Abstract

A system and technique to derive a position of a non-ADSB equipped aircraft using ADS-B information provided from an ADSB equipped aircraft and bi-static radar processing techniques.

Claims

1. A process for determining a position of a non-Automatic Dependent Surveillance Broadcast (non-ADSB) equipped aircraft comprises:

receiving, in a bi-static receiving system, a first group of signals from a first ADSB equipped aircraft;

receiving, in the bi-static receiving system, a second group of signals from a first non-ADSB equipped aircraft; and

processing the first and second group of signals in the bi-static receiving system using a bi-static radar processing technique by determining an azimuth position of an interrogator antenna using the first group of signals and determining a position of the non-ADSB equipped aircraft using the second group of signals.

2. The process of claim 1 wherein the first group of signals correspond to ADS-B signals.

3. The process of claim 1 wherein the second group of signals correspond to one of Mode A/C/S responses from aircraft having an ADS-B receiver disposed therein.

4. The process of claim 1 wherein the first group of signals correspond to ADSB signals transmitted from an ADSB equipped aircraft and the second group of signals correspond to Mode A/C/S signals transmitted from a non-ADSB equipped aircraft.

5. A system to derive a position of a non-ADSB equipped aircraft, the system comprising:

(a) an interrogator comprising;

an interrogator antenna; and

an interrogator receiver; and

(b) a bi-static receiving system comprising;

an antenna configured to receive Mode A/C/S signals and Mode ADS-B signals;

an interrogator processor configured to process Mode A/C/S signals;

an ADS-B processor configured to process ADS-B signals;

an azimuth determination processor coupled to receive signals from said ADS-B processor and to determine an azimuth position of the interrogator antenna; and

a position determination processor coupled to receive signals from said azimuth determination processor and said interrogator processor and to derive a position of the non-ADSB equipped aircraft.

6. The system of claim 5 wherein said bi-static receiving system is stationary.

7. The system of claim 5 wherein said bi-static receiving system is mounted on a movable vehicle.

8. The system of claim 5 wherein said interrogator is stationary.

9. The system of claim 5 wherein said interrogator is mounted on a movable vehicle.

10. The system of claim 5 wherein said interrogator corresponds to a secondary surveillance radar (SSR).

11. The system of claim 10 wherein said interrogator antenna is one of a rotating antenna or an electronically scanned antenna.

12. The system of claim 5 wherein said bi-static receiving system comprises an ADS-B receiver and a processor configured to perform bi-static radar processing.

13. A method to derive a position of a non-ADSB equipped aircraft comprising:

determining, in a bi-static receiving system, an azimuth position of an interrogator antenna as a function of time using one or more ADSB signals from an ADSB equipped aircraft; and

deriving a position of the non-ADSB equipped aircraft using the azimuth position of the interrogator antenna and one or more transponder signals from the non-ADSB equipped aircraft.

14. The method of claim 13 wherein determining an azimuth position of an interrogator antenna as a function of time comprises receiving one or more ADS-B reports in a bi-static receiving system and deriving an azimuth position of the interrogator radar based upon one or more of the one or more ADS-B reports.

15. The method of claim 13 wherein using the azimuth position of the interrogator antenna to derive a position of the non-ADSB equipped aircraft comprises:

transmitting one or more Mode A/C/S transponder signals from an interrogator having an interrogator antenna;

receiving, in the bi-static receiving system, one or more Mode A/C/S transponder reply signals provided by the non-ADSB equipped aircraft;

computing a longitude and latitude of the non-ADSB equipped aircraft using the azimuth position of the interrogator antenna, a range to the non-ADSB equipped aircraft and a known distance between the interrogator and the bi-static receiving system.