Aircraft navigation system and method of navigating an aircraft

• US 9,753,143 B2
• Filed: 11/10/2014
• Issued: 09/05/2017
• Est. Priority Date: 11/11/2013
• Status: Active Grant

• Current Assignee: Airbus Defence and Space GmbH
• Original Assignee: Airbus Defence and Space GmbH
• Inventors: Bianchi, Cristiano, Lohmiller, Winfried
• Primary Examiner(s): PAIGE, TYLER D
• Application Number:
  US15/035,819
• Publication Number:
  US 20160299231A1
• Time in Patent Office: 1,030 Days
• Field of Search: 701470, 701 14
• CPC Class Codes: G01S 19/18 Military applications
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: G01S 19/32 Multimode operation in a single same satellite system, e.g. GPS L1/L2
• CPC Class Codes: G05D 1/0022 characterised by the communication link data switching networks in general H04L12/00
• CPC Class Codes: G05D 1/0077 using redundant signals or controls
• CPC Class Codes: G08G 5/0004 Transmission of traffic-related information to or from an aircraft airborne radio transmission systems in general H04B7/185; airborne wireless networks H04W84/06

Abstract

An aircraft navigation system and navigation method. The system comprises a civil-certified GPS-receiver for determining first position information based on C/A-GPS-signals, and a military-type GPS-receiver for determining a second position information based on P(Y)-GPS-signals. A monitoring unit detects a first abnormal condition during jamming conditions within the C/A-GPS-signals. The unit compares the first position information with the second position information and detects a second abnormal condition when a difference between these position information is larger than a threshold value for more than a threshold duration. Upon detecting an abnormal condition, an alert procedure is initiated. In remotely piloted aircraft, Command & Control link-loss is also monitored and during link-loss, a transponder code automatically indicates communication failure. When in such situation an abnormal condition is additionally detected, a transponder code indicates airborne emergency and, subsequently, the aircraft navigation system is switched to navigating based on position information from the military-type GPS-receiver.

Claims

1. An aircraft navigation system for an unmanned aircraft comprising:

a civil-certified GPS-receiver,

a military-type GPS-receiver, and

a control device provided by a computer, the control device including a monitoring unit and an alerting unit,

wherein the civil-certified GPS-receiver is configured to determine a first position information based on civil course/acquisition code GPS signals (C/A-GPS-signals),

wherein the military-type GPS-receiver is configured to determine a second position information based on military precision code or encrypted precision code GPS signals (P(Y)-GPS-signals),

wherein the aircraft navigation system is configured to issue aircraft navigation signals based on the first position information when the aircraft is flying under civil-certified navigation control in civil airspace,

wherein at least one of;

the monitoring unit is configured to detect jamming of the C/A-GPS-signals, or

the monitoring unit is further configured to compare the first position information with the second position information, and to detect an occurrence of a difference between the first position information and the second position information being larger than a threshold value for more than a threshold duration, and

wherein the alerting unit is configured to initiate an alert procedure upon detection of at least one of the jamming of the C/A GPS signals and the occurrence of the difference between the first position information and the second position information being larger than a threshold value for more than a threshold duration.

2. The aircraft navigation system of claim 1,

wherein the aircraft navigation system is specifically configured for application in a remotely piloted aircraft and

wherein the monitoring unit is further configured to detect a Command &

Control link-loss while flying in civil airspace and for, upon such detection, automatically setting a transponder code in the aircraft to issuing a signal indicating communication failure, and

wherein the alerting unit is further configured to, upon detection of one of the jamming of the C/A GPS signals and the occurrence of the difference between the first position information and the second position information being larger than a threshold value for more than a threshold duration and simultaneous detection of Command &

Control link-loss, as part of the alert procedure automatically setting a transponder code in the aircraft to issuing a signal indicating airborne emergency and switching to issuing aircraft navigation signals based on the second position information.

3. The aircraft navigation system of claim 1, wherein the alert procedure comprises transmitting a specific warning signal to a pilot.

4. The aircraft navigation system of claim 1, wherein the civil-certified GPS-receiver is segregated with respect to the military-type GPS-receiver.

5. The aircraft navigation system of claim 1, wherein the civil-certified GPS-receiver and the military-type GPS-receiver are comprised in different line replaceable units.

6. A method of navigating an unmanned aircraft, the aircraft comprising an aircraft navigation system with

a civil-certified GPS-receiver,

a military-type GPS-receiver, and

a control device provided by a computer,

wherein the civil-certified GPS-receiver is adapted for determining a first position information based on civil course/acquisition code GPS signals (C/A-GPS-signals),

wherein the military-type GPS-receiver is adapted for determining a second position information based on military precision code or encrypted precision code GPS signals (P(Y)-GPS-signals),

the method comprising:

determining the first position information by the civil-certified GPS-receiver,

determining the second position information by the military-type GPS-receiver,

the aircraft navigation system navigating the aircraft according to aircraft navigation signals based on the first position information when the aircraft is flying under civil-certified navigation control in civil airspace,

at least one of

detecting jamming of the C/A-GPS-signals, or

comparing the first position information with the second position information, and detecting an occurrence of a difference between the first position information and the second position information being larger than a threshold value for more than a threshold duration, and

initiating an alert procedure upon detection of one of the jamming of the C/A GPS signals and the occurrence of the difference between the first position information and the second position information being larger than a threshold value for more than a threshold duration.

7. The method of claim 6, further comprising:

detecting a Command &

Control link-loss while flying in civil airspace and, upon such detection, automatically setting a transponder code in the aircraft to issuing a signal indicating communication failure, and

upon detection of at least one of the jamming of the C/A GPS signals and the occurrence of the difference between the first position information and the second position information being larger than a threshold value for more than a threshold duration and simultaneous detection of Command &

Control link-loss, as part of the alert procedure, automatically setting a transponder code in the aircraft to issuing a signal indicating airborne emergency and switching to issuing aircraft navigation signals based on the second position information.

8. The method of claim 6, wherein the alert procedure comprises transmitting a specific warning signal to a pilot.

9. A non-transitory computer readable medium comprising computer readable code stored thereon which, when executed by a computer, is configured to control the method according to claim 6.

10. An aircraft navigation system comprising:

a civil-certified GPS-receiver,

a military-type GPS-receiver, and

a control device provided by a computer, the control device including a monitoring unit and an alerting unit,

wherein the civil-certified GPS-receiver is configured to determine a first position information based on civil course/acquisition code GPS signals (C/A-GPS-signals),

wherein the military-type GPS-receiver is configured to determine a second position information based on military precision code or encrypted precision code GPS signals (P(Y)-GPS-signals),

wherein the aircraft navigation system is configured to issue aircraft navigation signals based on the first position information when the aircraft is flying under civil-certified navigation control in civil airspace,

wherein at least one of;

the monitoring unit is configured to detect jamming of the C/A-GPS-signals, or

the monitoring unit is further configured to compare the first position information with the second position information, and to detect an occurrence of a difference between the first position information and the second position information being larger than a threshold value for more than a threshold duration, and

wherein the alerting unit is configured to initiate an alert procedure upon detection of at least one of the jamming of the C/A GPS signals and the occurrence of the difference between the first position information and the second position information being larger than a threshold value for more than a threshold duration.