Apparatus and method to generate and detect virtual targets

• US 8,604,965 B2
• Filed: 02/08/2011
• Issued: 12/10/2013
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Federal Aviation Administration/Department of Transportation/Government of The United States
• Original Assignee: Federal Aviation Administration/Department of Transportation
• Inventors: Jennings, Richard Earl, Pagano, Thomas Lee
• Primary Examiner(s): Keith, Jack W
• Assistant Examiner(s): BYTHROW, PETER M
• Application Number:
  US12/929,672
• Publication Number:
  US 20110210884A1
• Time in Patent Office: 1,036 Days
• Field of Search: 342 13- 20, 342 29- 51, 342 94- 97, 342159-175
• US Class Current: 342/37
• CPC Class Codes: G01S 13/781 Secondary Surveillance Radar [SSR] in general
• CPC Class Codes: G01S 7/4004 of parts of a radar system

Abstract

An apparatus and method to generate and detect virtual targets. Position information for one or more virtual targets is calculated onboard a vehicle from real position information obtained from GPS satellites or other external or internal sources. This virtual position information is coded, mixed with a carrier frequency, amplified, and radiated to a nearby test vehicle, such as an aircraft. The amplitude of the radiated signal is adjusted such that the signal containing the virtual position information is received by the test aircraft only. The radiated signal thus adjusted is below the detection threshold of any aircraft further away. The test aircraft decodes the signal and interprets the decoded virtual position information as real aircraft in its vicinity. The coded signals may be structured to comply with the requirements of the FAA'"'"'s ADS-B system. The apparatus may be mounted on the test aircraft itself, or on a nearby aircraft.

Claims

1. An apparatus, comprising:

a) a first position detector configured to acquire real position information associated with a real vehicle and generate signal containing said first real vehicle position information; and

,

b) A target calculator configured to receive said signal containing said first real vehicle position information and calculate therefrom virtual position information for at least one virtual target, encode said virtual position information into a format that is interpreted by a second position detector and generate encoded virtual position information for each of said virtual targets; and

,

c) A signal generator configured to receive said encoded virtual position information for each of said virtual targets, combine said encoded virtual position information with a radio frequency carrier signal to produce a modulated RF signal; and

,

d) A signal amplifier configured to receive said modulated RF signal, amplify said modulated RF signal to generate an amplified modulated RF signal containing the radio frequency carrier signal and the encoded virtual position information for each of said virtual targets; and

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e) an antenna configured to receive and then radiate said amplified modulated RF signal generated by said signal amplifier; and

,

wherein said signal amplifier is adjusted to radiate said amplified modulated RF signal by said antenna with only that strength sufficient to enable said second position detector to acquire said virtual position information.

2. The apparatus of claim 1, wherein said first position detector is a GPS receiver and said second position detector is an ADS-B receiver.

3. The apparatus of claim 1, wherein the first position detector and said second position detector are ADS-B receivers.

4. The apparatus of claim 1, wherein said first position detector and said second position detector are located on the same vehicle.

5. The apparatus of claim 1, wherein said first position detector and said second position detector are located on separate vehicles.

6. The apparatus of claim 2, wherein said first position detector and said second position detector are located on the same vehicle.

7. The apparatus of claim 2, wherein said first position detector and said second position detector are located on separate vehicles.

8. The apparatus of claim 3, wherein said first position detector and said second position detector are located on the same vehicle.

9. The apparatus of claim 3, wherein said first position detector and said second position detector are located on separate vehicles.

10. A method of generating and detecting virtual targets

(a) wherein a first GPS receiver located on a first real vehicle performs the step of acquiring real position information associated with said first real vehicle;

and,

(b) wherein a Virtual Target Generator performs the steps of;

(b1) calculating virtual position information based on said real position information for at least one virtual target; and

,

(b2) encoding said virtual position information into a format that may be decoded; and

,

(b3) combining said encoded virtual position information with an RF carrier frequency to produce a modulated RF signal containing said encoded virtual position information; and

,

(b4) adjusting the amplitude of said modulated RF signal; and

(b5) providing said modulated RF signal to an antenna; and

,

(c) wherein said antenna performs the step of radiating said modulated RF signal with only that signal strength, as determined by adjusting the amplitude of said modulated RF signal, sufficient to be acquired by a second GPS receiver located on a second real vehicle; and

,

(d) wherein said second GPS receiver performs the step of decoding said modulated RF signal to produce virtual position information for said virtual targets such that said second real vehicle detects said virtual targets.

11. The method of claim 10, wherein said encoded virtual position information is compliant with the requirements of ADS-B.

12. The method of claim 10, wherein said first real vehicle and said second real vehicle are separate vehicles.

13. The method of claim 10, wherein said first real vehicle and said second real vehicle are the same vehicle.

14. The method of claim 11, wherein said first real vehicle and said second real vehicle are separate vehicles.

15. The method of claim 11, wherein said first real vehicle and said second real vehicle are the same vehicle.

16. An apparatus to generate and detect virtual targets comprising:

a) a GPS receiver configured to acquire real position information associated with a first real aircraft and generate a signal containing said first real aircraft position information, and

b) a virtual target position computer configured to receive said signal containing said first real aircraft position information, calculate for at least one virtual aircraft, virtual aircraft position information derived from said first real aircraft real aircraft position information, and generate a signal containing said virtual aircraft position information, and

c) an ADS-B message controller configured to receive said signal containing virtual aircraft position information associated with each of said virtual aircraft, schedule the individual 1090 ES messages required for each of the said virtual aircraft, and convert the said virtual aircraft position information associated with each of said virtual aircraft into signals that conform to the requirements of ADS-B messages, and

d) a digital signal generator configured to receive said signals provided by said ADS-B message controller, construct said signals provided by said ADS-B message controller into pulse position modulated data along with preamble data pulses to satisfy the required signal characteristics of 1090 ES messages to produce a baseband signal, and

e) an RF modulator configured to receive said baseband signal and combine said baseband signal with a 1090 MHz RF carrier signal to produce a modulated baseband signal containing the virtual aircraft position information converted into signals that conform to ADS-B messages, and

f) an RF signal amplifier configured to receive said modulated baseband signal and amplify said modulated baseband signal, and

g) an antenna configured to receive the amplified modulated baseband signal and then radiate said amplified modulated baseband signal, and

wherein said RF signal amplifier amplifies said modulated baseband signal only to that amplitude that the radiated amplified modulated baseband signal reaches an ADS-B receiver located on said first real aircraft.

17. An apparatus to generate and detect virtual targets comprising:

a) a GPS receiver configured to acquire real position information associated with a first real aircraft and generate a signal containing said first real aircraft position information, and

b) a virtual target position computer configured to receive said signal containing said first real aircraft position information, calculate for at least one virtual aircraft, virtual aircraft position information derived from said first real aircraft real aircraft position information, and generate a signal containing said virtual aircraft position information, and

c) an ADS-B message controller configured to receive said signal containing virtual aircraft position information associated with each of said virtual aircraft, schedule the individual 1090 ES messages required for each of the said virtual aircraft, and convert the said virtual aircraft position information associated with each of said virtual aircraft into signals that conform to the requirements of ADS-B messages, and

d) a digital signal generator configured to receive said signals provided by said ADS-B message controller, construct said signals provided by said ADS-B message controller into pulse position modulated data along with preamble data pulses to satisfy the required signal characteristics of 1090 ES messages to produce a baseband signal, and

e) an RF modulator configured to receive said baseband signal and combine said baseband signal with a 1090 MHz RF carrier signal to produce a modulated baseband signal containing the virtual aircraft position information converted into signals that conform to ADS-B messages, and

f) an RF signal amplifier configured to receive said modulated baseband signal and amplify said modulated baseband signal, and

g) an antenna configured to receive the amplified modulated baseband signal and then radiate said amplified modulated baseband signal, and

wherein said RF signal amplifier amplifies said modulated baseband signal only to that amplitude that the radiated amplified modulated baseband signal reaches an ADS-B receiver located on a separate real aircraft.