Combined ground and satellite system for global aircraft surveillance guidance and navigation

• US 5,627,546 A
• Filed: 09/05/1995
• Issued: 05/06/1997
• Est. Priority Date: 09/05/1995
• Status: Expired due to Fees

• Current Assignee: Robert P. Crow
• Original Assignee: Robert P. Crow
• Inventors: Crow, Robert P.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): PHAN, DAO LINDA
• Application Number:
  US08/523,348
• Time in Patent Office: 609 Days
• Field of Search: 342/32, 342/352, 342/34, 342/49, 342/353, 342/455, 342/456, 364/439, 364/451, 364/429, 364/461
• US Class Current: 342/352
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/91 for traffic control G01S13/93 takes precedence
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft
• CPC Class Codes: G01S 13/935 for terrain-avoidance
• CPC Class Codes: G08G 5/0013 with a ground station
• CPC Class Codes: G08G 5/0043 Traffic management of multiple aircrafts from the ground G08G5/003 takes precedence; data processing specially designed for resource management, e.g. scheduling or allocating time, human or machine resources G06Q10/06
• CPC Class Codes: G08G 5/0082 for monitoring traffic from a ground station radar or analogous systems specially adapted for traffic control G01S13/91
• CPC Class Codes: H04B 7/18506 Communications with or from aircraft, i.e. aeronautical mobile service
• CPC Class Codes: H04B 7/18508 with satellite system used as relay, i.e. aeronautical mobile satellite service
• CPC Class Codes: H04B 7/1851 Systems using a satellite or space-based relay H04B7/18508, H04B7/18521 take precedence; providing specific services H04B7/18523 - H04B7/18576
• CPC Class Codes: H04K 3/255 based on redundancy of transmitted data, transmission path or transmitting source
• CPC Class Codes: H04K 3/90 related to allowing or preventing navigation or positioning, e.g. GPS

Abstract

The present invention provides a combined ground and satellite system for global aircraft surveillance, navigation, landing guidance and collision avoidance which comprises a satellite subsystem consisting of both a satellite constellation and associated ground stations, and a ground subsystem consisting of a network of ground stations, together with an airborne subsystem comprised of a transponder unit located in each of the aircraft using the system. A high speed two-way data link is provided between each of the subsystems using spread spectrum technology to permit overlaying and operation of the system in an existing band of narrow channels with minimum mutual interference. The system of the invention is reliable because of the redundant subsystems, and is not subject to failure. Also, the system provides for computations to be made on the ground, rather than in the aircraft, thereby reducing the size and complexity of the airborne equipment. The system also achieves a high degree of precision, as compared with the prior art systems. The system also provides air/ground data communication.

Claims

1. A combined ground and satellite system for providing aircraft guidance, said system comprising:

a satellite subsystem which includes a constellation of satellites and a plurality of ground stations positioned at selected locations;

a ground subsystem which includes a network of ground stations positioned at selected locations; and

an airborne subsystem which includes a plurality of transponder units located in respective ones of aircraft utilizing the system;

the transponder units of the airborne subsystem each including means providing a first spread spectrum band data link with the satellites and ground stations of the ground subsystem, the satellites each including means providing a second spread spectrum band data link with the airborne subsystem, and the ground stations of the ground subsystem each including means providing a third spread spectrum band data link with the airborne subsystem, each of said spread spectrum band data links including means providing a selected form of spread spectrum coding comprising a plurality of different codes to provide identification of individual ones of said satellites, and ground stations.

2. The combined ground and satellite system defined in claim 1, in which said data links have spread spectrum bands located in the present day TACAN/DME signal channels (978 MHz-1213 MHz) with spread spectrum overlay.

3. The combined ground and satellite system defined in claim 2, in which each of the three spread spectrum bands are of the order of 50 MHz wide.

4. The combined ground and satellite system defined in claim 3, in which said third data link has a spread spectrum band positioned between the first and second present day Air Traffic Control (ATC) signal channels of 1030 MHz and 1090 MHz respectively, and said second and first data links have respective spread spectrum bands positioned adjacent to one another above said second present day Air Traffic Control (ATC) signal channel (1090 MHz).

5. The combined ground and satellite system defined in claim 3, in which each of said three data links is a high speed type which obtains and provides precise three-dimensional aircraft position data for an addressed aircraft, said data being available not only to the addressed aircraft but also to other aircraft in the vicinity.

6. The combined ground and satellite system defined in claim 1, in which the ground stations of the satellite subsystem each includes means for transmitting interrogation signals to the transponder unit of a selected aircraft, and said ground stations of said satellite subsystem each including further means responsive to reply signals from the transponder unit of the selected aircraft to measure the distances between the selected aircraft and at least three of the satellites, and said ground stations of the satellite subsystem including further means for processing said reply signals to compute and transmit to the selected aircraft and to other aircraft in the vicinity latitude, longitude and altitude data concerning the selected aircraft.

7. The combined ground and satellite system defined in claim 6, in which the signals transmitted by said satellite subsystem ground stations comprise digitally encoded and discretely addressed interrogation pulses directed to a selected one of said satellites to be repeated to the selected aircraft thereby.

8. The combined ground and satellite system defined in claim 7, in which the ground stations of the satellite subsystem each include means for measuring the delay between said interrogation pulses and reply signals to determine said distances.

9. The combined ground and satellite system defined in claim 8, in which the ground stations of the ground subsystem each include an interferometer antenna array for measuring the incident angles of the wave fronts of the reply signals, and each including processing means coupled to the corresponding interferometer antenna for determining azimuth angles.

10. The combined ground and satellite system defined in claim 1, in which the ground stations of the ground subsystem each include means for transmitting way point data over said third data link to the airborne subsystems representing course deviation and distance to selected way points.

11. The combined ground and satellite system defined in claim 1, in which certain of said ground stations of said ground subsystem are located in terminal areas, and such terminal area ground stations each include a vertical interferometer antenna array and associated receiving and processing equipment to enable the system to produce and transmit precise landing guidance signals to the aircraft utilizing the system.

12. The combined ground and satellite system defined in claim 11, in which the processing equipment of such terminal area ground stations of said ground subsystem each includes means for computing distance and angle offsets to the outputs of azimuth and elevation measuring equipment installed at airports at which the aircraft are guided to landings.

13. The combined ground and satellite system defined in claim 1, in which the three subsystems each include means for transmitting interrogation and reply signals over said first, second and third spread spectrum band data links, with each such signal comprising digitally encoded and discretely addressed binary bit signals using bi-phase or quadra-phase coding in conjunction with high speed spread spectrum coding.

14. The combined ground and satellite system defined in claim 1, in which the individual aircraft of the airborne subsystem receive data from either the ground or the satellite subsystems, or both, and utilize this data for navigation, landing guidance, collision warning and avoidance, and information or instructions from Air Traffic Control.

15. The combined ground and satellite system defined in claim 1, in which the ground or the satellite subsystems, or both, provide three-dimensional position data on individual aircraft of the airborne subsystem for Air Traffic Control surveillance.