Discrete address beacon, navigation and landing system (DABNLS)

• US 4,454,510 A
• Filed: 03/23/1981
• Issued: 06/12/1984
• Est. Priority Date: 12/18/1978
• Status: Expired due to Term

• Current Assignee: Robert P. Crow
• Original Assignee: Robert P. Crow
• Inventors: Crow, Robert P.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US06/246,174
• Time in Patent Office: 1,177 Days
• Field of Search: 244/183, 364/439, 364/451, 364/429, 364/430, 364/424, 364/440, 364/441, 343/5 GC, 343/112 TC, 343/108 R, 343/6.5 R, 343/112 CA, 343/5 LS, 343/6.5 LC, 343/112 C, 343/455, 343/456, 343/399
• US Class Current: 342/32
• CPC Class Codes: G01S 13/79 Systems using random coded signals or random pulse repetition frequencies , e.g. "Separation and Control of Aircraft using Non synchronous Techniques" [SECANT]
• CPC Class Codes: G09B 9/006 for locating or ranging of objects

Abstract

An aircraft surveillance, navigation, landing, guidance and collision avoidance system is provided which takes the form of a two-way data communication link between each of a plurality of controlled aircraft and a ground station, and appropriate measuring equipment at the ground station which provides three-dimensional position data on the ground for air traffic control purposes; and which also provides three-dimensional position data in the aircraft for navigation, landing guidance and collision avoidance purposes, as well as a two-way air/ground data link for miscellaneous data and control purposes. The system of the invention comprises the combination of a ground transmitter/receiver station and airborne transponders mounted in the aircraft. The ground transmitter broadcasts discrete aircraft addressed interrogation pulses which are coded to contain position and/or other data. The transponders in all aircraft receive and decode the interrogation pulses, and the discretely addressed aircraft transmits appropriately timed reply pulses to the ground receiver which contain altitude and other data. Other aircraft utilize the received position information for collision avoidance purposes. The ground receiver measures the incident angles of the reply signal pulses and their precise time delays with respect to the interrogation pulses, so as to provide aircraft position and other data to the ground station, and to provide additional data for transmission to the aircraft on the following interrogation pulses.

Claims

1. In combination:

a ground station including a first transmitter for transmitting omnidirectionally discretely addressed code interrogation pulses to each of a plurality of aircraft in the vicinity of the ground station containing position data concerning each of the aircraft;

a transponder mounted in each of the aircraft including a receiver for receiving and decoding coded interrogation pulses from the ground station, and including a second transmitter for transmitting appropriately timed coded reply pulses to the ground station containing altitude, discrete address, and other data concerning each of the aircraft; and

a receiving system included in the ground station for measuring the incident angles and time delay of the reply pulses with respect to the interrogation pulses, computer means included in the receiving system for determining slant-range correction and for providing navigational data including the latitude/longitude coordinates of the aircraft in the vicinity of the ground station thereby to provide data at the ground station relating to the position of each aircraft for use at the ground station and for transmission to each of the aircraft by said first transmitter.

2. The combination defined in claim 1, in which said computer means provides three-dimensional positional data relating to all aircraft in the vicinity of the ground station for air traffic control purposes.

3. The combination defined in claim 1, in which said computer means provides data for retransmission to all of the aircraft by said first transmitter for navigation, landing guidance and collision avoidance purposes.

4. The combination defined in claim 1, and which includes means included in said ground station for forming a data link for auxiliary data between the ground station and all of the aircraft in the vicinity of the ground station.

5. The combination defined in claim 1, in which said ground station receiving system includes means for precisely timing below the 50% point on the leading edges of the interrogation pulses and the reply pulses for range purposes.

6. The combination defined in claim 1, in which said computer means provides latitude/longitude coordinates and upon request off-set course area navigation guidance data for transmission to the aircraft.

7. The combination defined in claim 1, in which said computer means provides three-dimensional landing guidance data for all aircraft from ground facilities which may have positions off-set with respect to the runway.

8. The combination defined in claim 1, in which said ground station receiving system includes interferometer antenna and receiver means with multi-path effects suppression processing responsive to the reply pulses for determining the bearing and elevation angles of each of the aircraft.

9. The combination defined in claim 1, in which the ground station includes a DME transponder for transmitting TACAN/DME reply pulse pairs at a higher amplitude than the aforesaid discretely addressed coded interrogation pulses, and in which said ground station includes a DME decoder which discriminates against the aforesaid discretely addressed coded reply pulses.

10. The combination defined in claim 9, in which the aircraft includes a DME interrogator in addition to said transponder, and selectable control circuitry for said DME interrogator and transponder.

11. In combination:

a ground station including a first transmitter for transmitting omni-directionally discretely addressed code interrogation pulses to each of a plurality of aircraft in the vicinity of the ground station containing position data concerning each of the aircraft;

a transponder mounted in each of the aircraft including a receiver for receiving and decoding coded interrogation pulses from the ground station, and including a second transmitter for transmitting appropriately timed coded reply pulses to the ground station containing altitude, discrete address, and other data concerning each of the aircraft; and

a receiving system included in the ground station for measuring the incident angles and time delay of the reply pulses with respect to the interrogation pulses, computer means included in the receiving system for determining slant range correction and for providing navigational data including the coordinates of the aircraft in the vicinity of the ground station thereby to provide data at the ground station relating to the position of each aircraft for use at the ground station and for transmission to each of the aircraft by said first transmitter, in which said computer means provides data for forming three-dimensional position offsets for landing guidance of all of the aircraft, and said computer means further provides horizontal and vertical course softened data as the aircraft approaches a runway by converting from angular to lineal course deviations.

12. In combination:

a ground station including a first transmitter for transmitting omni-directionally discretely addressed code interrogation pulses to each of a plurality of aircraft in the vicinity of the ground station containing position data concerning each of the aircraft;

a transponder mounted in each of the aircraft including a receiver for receiving and decoding coded interrogation pulses from the ground station, and including a second transmitter for transmitting appropriately timed coded reply pulses to the ground station containing altitude and other data concerning each of the aircraft; and

a receiving system included in the ground station for measuring the incident angles and time delay of the reply pulses with respect to the interrogation pulses, computer means included in the receiving system for determining slant-range correction and for providing navigational data including the coordinates of the aircraft in the vicinity of the ground station thereby to provide data at the ground station relating to the position of each aircraft for use at the ground station and for transmission to each of the aircraft by said first transmitter, in which said computer means provides automatic flare guidance in response to wheel-to-antenna height signals and other data signals received from the aircraft.

13. An aircraft surveillance and navigation system including:

a ground station including an omni-directional antenna, an interrogator sub-system including a transmitter coupled to said omni-directional antenna for transmitting coded interrogation pulses discretely addressed to each of a plurality of aircraft in the vicinity of the ground station, an azimuth receiving interferometer antenna array for receiving signals from said plurality of aircraft, a receiver array coupled to the interferometer receiving antenna array for respectively receiving discretely addressed coded reply pulses from respective ones of said aircraft, means including an angle processor coupled to the receiver array and responsive to angular data signals from the respective individual receivers of the receiver array for computing the azimuth angle of each of the aircraft, means including a receiver coupled to said omni-directional antenna for measuring the timing between the leading edges of the interrogation pulses and the reply pulses of each of the aircraft, range circuitry coupled to said receiver and responsive to signals therefrom to determine the range of each of the aircraft, decoder circuitry coupled to said receiver for providing signals representative of the identification address and altitude of all of the aircraft and of other data of all of the aircraft, and a coordinate and off-set course computer responsive to azimuth angle signals from said angle processor, and to range signals from said range circuitry, and to altitude signals from said decoder circuitry, to provide slant-range corrected signals, latitude/longitude coordinate signals and off-set course deviation signals for all requesting aircraft; and

a transponder located in each of the aircraft for receiving the coded interrogation pulses from the interrogator sub-system and for transmitting the coded reply pulses thereto.

14. The aircraft surveillance and navigation system defined in claim 13, and which includes an array of analog/digital converters coupled to said receiver array to provide angular data signals corresponding to each of the aircraft to the angle processor in digital form.

15. The aircraft surveillance and navigation system defined in claim 13, in which said ground station includes aircraft file memory means coupled to said coordinate and off-set computer, to said range circuitry, and to said decoder circuitry for storing data signals concerning all of the aircraft together with the associated discrete addresses of all of the aircraft to determine aircraft interrogation sequencing efficiently so as to space replies and avoid overlap, and to provide adequate data rate for all modes of operation.

16. The aircraft surveillance and navigation system defined in claim 15, and which includes encoder means coupled to said aircraft file memory and to said transmitter for causing the transmitter to transmit the interrogation pulses to all of the aircraft containing data stored in the aircraft file memory pertaining to a particular aircraft.

17. The aircraft surveillance and navigation system defined in claim 13, in which said transponder includes a transmitter and a receiver, altitude sensing means for producing signals indicative of the altitude of the aircraft, and encoder means coupled to the sensing means for producing altitude-coded pulses, including discrete addresses, and other data, for introducing such pulses to the last-named transmitter for transmission to the ground station.

18. An aircraft surveillance and navigation system including:

a ground station including an omni-directional antenna, an interrogator sub-system including a first transmitter coupled to said omni-directional antenna for transmitting coded interrogation pulses discretely addressed to each of a plurality of aircraft in the vicinity of the ground station, an azimuth receiving antenna array for receiving signals from said plurality of aircraft, a receiver array coupled to the receiving antenna array for respectively receiving discretely addressed coded reply pulses from respective ones of said aircraft, means including an angle processor coupled to the receiver array for computing the azimuth angle of each of the aircraft, means including a receiver coupled to said omni-directional antenna for measuring the timing between the leading edges of the interrogation pulses and the reply pulses of each of the aircraft, range circuitry coupled to said receiver and responsive to signals therefrom to determine the range of each of the aircraft, decoder circuitry coupled to said receiver for providing signals representative of the identification address and altitude of all of the aircraft and of other data of all of the aircraft, and a coordinate and off-set course computer responsive to azimuth angle signals from said angle processor, and to range signals from said range circuitry, and to altitude signals from said decoder circuitry, to provide slant-range corrected signals, position coordinate signals and off-set course deviation signals for all requesting aircraft; and

a transponder located in each of the aircraft for receiving the coded interrogation pulses from the interrogator sub-system and for transmitting coded pulses thereto, said transponder including a second transmitter and a second receiver, altitude sensing means for producing signals indicative of the altitude of the aircraft, and encoder means coupled to the sensing means for producing altitude-coded pulses and for introducing such pulses to said second transmitter for transmission to the ground signal, and which includes decoding means coupled to said second receiver for producing signals representative of the latitude, longitude and altitude of all of the aircraft.

19. The aircraft surveillance and navigation system defined in claim 18, in which said transponder further includes collision avoidance processing means coupled to said last-named decoding means.

20. The aircraft surveillance and navigation system defined in claim 18, in which said ground station further includes an elevation receiving antenna array, a receiver array coupled to the elevation receiving antenna array for producing signals representative of the elevation angle of the aircraft, and computer means for determining the altitude of each of the aircraft independent of any reported altitude.

21. The aircraft surveillance and navigation system defined in claim 18, and which includes elevation angle and flare measuring stations for providing flare guidance for the aircraft with respect to one or more runways.

22. The aircraft surveillance and navigation system defined in claim 21, in which the ground station and the elevation angle and flare measuring stations are positioned adjacent to one or more runways, and the elevation angle and flare measuring stations are displaced from the ground station along the runway by a predetermined distance.

23. The aircraft surveillance and navigation system defined in claim 18, and which includes an elevation angle or flare measuring station integrated with said ground station and serving to provide flare guidance for the aircraft with respect to one or more runways.

24. The aircraft surveillance and navigation system defined in claim 18, and which includes a primary elevation angle and flare measuring station and a secondary elevation angle and flare measuring station, said secondary elevation angle and flare measuring station being integrated with said ground station and located adjacent to one or more runways, and said primary elevation angle and flare measuring station being displaced from said secondary elevation angle and flare measuring station along the runway, and both said primary elevation angle and flare measuring station and said secondary elevation angle and flare measuring station providing flare guidance for the aircraft with respect to one or more runways.

25. The aircraft surveillance and navigation system defined in claim 18, in which said ground station includes a computer for providing the aircraft with course data and distance data with respect to particular waypoints, and each aircraft includes a controller for enabling the pilot to enter selected course and waypoint coordinate date into the computer by means of an extended reply pulse.

26. The aircraft surveillance and navigation system defined in claim 18, in which the coded interrogation pulses include function and channel/facility sub-frames.