METHOD AND DEVICE FOR ESTIMATING A DISTANCE

• US 20150247914A1
• Filed: 10/05/2012
• Published: 09/03/2015
• Est. Priority Date: 10/05/2012
• Status: Abandoned Application

• Current Assignee: FLARM Technology GmbH
• Original Assignee: FLARM Technology GmbH
• Inventors: Mader, Urban, Rothacher, Urs
• Application Number:
  US14/433,440
• Publication Number:
  US 20150247914A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 13/103 particularities of the measurement of the distance G01S13/12, G01S13/14, G01S13/16, G01S13/18 and G01S13/20 take precedence
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft
• CPC Class Codes: G01S 5/0072 Transmission between mobile stations, e.g. anti-collision systems
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• CPC Class Codes: G01S 5/0284 Relative positioning
• 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: G08G 5/0095 Aspects of air-traffic control not provided for in the other subgroups of this main group
• CPC Class Codes: G08G 5/04 Anti-collision systems
• 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

An improved method for avoiding mid-air collision in aviation is disclosed. The method relies on a calibration of radio signal intensities I with radio signal encoded position information L. In other words, after a first reception of a radio signal S advantageously comprising remote aircraft position information L, the radio signal intensity I is measured and a correction factor C is derived. During a next encounter of the radio signal S, a second distance estimation d can be derived using the signal intensity I and the correction factor C. Preferably, relative positioning data is acquired together with the correction factor C and a plurality of correction factors for different relative positions is combined in an at least partly continuous correction function.

Claims

1. A method for deriving at least one correction factor for at least one first estimation of a distance between a first position of at least one receiver and a second position of at least one transmitter, the method comprising:

receiving by means of said receiver at least one radio signal which is transmitted by said transmitter;

measuring a signal intensity of said radio signal at said first position of said receiver;

deriving second position information indicative of said second position of said transmitter;

measuring said first position of said receiver and deriving first position information indicative of said first position; and

deriving said correction factor for said first estimation of said distance using said first position information, said second position information, and said signal intensity.

2. The method of claim 1 further comprising:

deriving said first estimation of said distance using said signal intensity.

3. The method of any claim 1 wherein said first position informal ion is at least indicative of an altitude, a latitude, and a longitude of said /receiver and/or wherein said second position information is at least indicative of an altitude, a latitude, and a longitude of said transmitter.

4. The method of claim 1 wherein said radio signal further comprises an identifier, in particular a unique identifier, of said transm itter.

5. The method of claim 1 further comprising:

deriving relative position information indicative of a relative position of said transmitter with regard to said receiver, and in particular wherein said relative position information comprises a relative azimuth angle and/ora relative inclination angle,

wherein said correction factor is derived using said relative position information.

6. The method of claim 5 wherein said correction factor is indicative of directional characteristics of a receiver antenna of said receiver and/or of directional characteristics of a transmitter antenna of said transmitter.

7. The method of claim 1 further comprising:

deriving at least two correction factors (C _100, C_100′

, C_101′

).

8. The method of claim 7 wherein said correction factors are derived for the same transmitter at different times, and in particular wherein the method further comprises:

deriving an averaged correction factor using said correction factors.

9. The method of any claim 7 wherein said correction factors are derived for different transponders with different second positions.

10. The method of claim 7 further comprising:

issuing a reception warning if an absolute difference between said correction factors exceeds a threshold.

11. The method of claim 5 further comprising:

deriving at;

least two correction factors; and

deriving a relative-position-dependent correction function using at least two of said correction factors and using said relative position information.

12. The method of claim 1 further comprising:

deriving a distance value indicative of said distance using said first position information and said second position information,

wherein said correction factor is derived using said distance value and said signal intensity.

13. The method of claim 1 further comprising:

deriving an output power value of said transmitter using said first position information, said second position information, and said signal intensity.

14. The method of claim 1 wherein said at least one transmitter comprises at least one of the group consisting of

an A DS-B Out capable transponder and

a HARM and a Mode C or a Mode S transponder and/or

wherein said radio signal comprises at least one of the group consisting of

an ADS-SB Out signal and

a FLARM and a Mode C signal.

15. The method of claim 1 wherein said radio signal comprises said second position information indicative of said second position of said transmitter.

16. The method of claim 1 wherein said second position information indicative of said second position of said transmitter is downloaded from said transmitter or from a traffic monitoring service, in particular from air traffic control.

17. A method for deriving at least one second estimation of a distance between a first position of at least one receiver and a second position of at least one transmitter, the method comprising:

receiving by means of said receiver at least one radio signal which is transmitted by said transmitter;

measuring a signal intensity of said radio signal at said first position of said receiver;

deriving said second estimation of said distance using said signal intensity, in particular solely using said signal intensity, and using at least one correction factor of claim 1 and/or a correction function of claim 11,

wherein a statistical deviation of said second estimation of said distance from said distance is smaller than a statistical deviation of said first estimation of said distance from said distance.

18. The method of claim 17 further comprising:

deriving said first estimation of said distance using, said signal intensity, in particular solely using said signal intensity.

19. The method of claim 17 further comprising:

issuing a warning, in particular a collision warning, to an operator when said second estimation of said distance decreases below a distance threshold.

20. The method of claim 17 further comprising:

deriving an estimation of a future distance between said receiver and said transmitter using said first position of said receiver, a current velocity of said receiver, and/or a current acceleration of said receiver and/or furthermore using said second position of said transmitter, a current velocity of said transmitter, and/or a current acceleration of said transmitter,

wherein a warning is additionally issued when said estimation of said future distance decreases below a distance threshold.

21. The method of claim 20 further comprising:

deriving an estimation of a future trajectory of said receiver, in particular using said first position of said receiver a current velocity of said receiver, and/or a current acceleration of said receiver, and/or

deriving an estimation of a future trajectory of said transmitter, in particular using said second position of said transmitter, a current velocity of said transmitter, and/or a current acceleration of said transmitter,

wherein said estimation of said future trajectory of said receiver and/or said estimation of said future trajectory of said transmitter is or are used in said step of de-riving said estimation of said future distance between said receiver and said transmitter.

22. The method of claim 19 further comprising:

suppressing said warning if an altitude of said transmitter differs more than 152.4 m, particularly 304,8 m, in particular 457.2 m, from an altitude of said receiver.

23. The method of claim 17 wherein radio signal further comprises an identifier, in particular a unique identifier, for identifying said radio signal of said transmitter.

24. The method of claim 17 further comprising:

deriving relative position information indicative of a relative position of said transmitter with regard to said receiver, and in particular wherein said relative position information comprises a relative azimuth angle ((p) and/or a relative inclination angle.

25. The method of claim 24 wherein said correction factor and/or said correction function is or are dependent on said relative position of said transmitter with regard to said receiver and wherein said correction factor and/or said correction function for deriving said second estimation of said distance is or are selected and/or evaluated using said relative position information.

26. The method of claim 17 further comprising:

filtering said radio signal prior to carrying out said step of measuring said signal intensity.

27. The method of claim 17 wherein said at least one transmitter comprises at least one of the group consisting of

an ADS-B Out capable transponder,

a FLARM system,

a Mode 3A or A capable transponder,

a Mode C capable transponder, and

a Mode S capable transponder and/or

wherein said radio signal comprises at least one of the group consisting of

an ADS-B Out signal,

a FLARM signal.

a Mode 3A or A signal,

a Mode C signal, and

a Mode S

28. A collision warning device, in particular for use in aviation, comprising:

at least one receive at a first position with at least one receiver antenna for receiving at least one radio signal which is transmitted by at least one transmitter at a second position, wherein said first position and said second position are separated by a variable distance;

a localization device, in particular a GNSS receiver, for measuring said first position of said receiver and deriving first position information indicative of said first position;

an output unit for issuing a warning, in particular a collision warning, to an operator,

a control unit adapted and structured to carry out the steps of a method of claim 1 for deriving at least one correction factor and to carry out the steps of a method of claim 17 for deriving at least one second estimation of said distance.

29. The collision warning device of claim 28 further comprising an interface for connecting said collision warning device to a flight control system for receiving flight data, in particular a current velocity and/or a current acceleration and/or a current bearing and/or a current rudder position, from said flight control system.

30. The collision warning device of claim 28 further comprising a memory for storing said correction factor and/or said correction function and/or said first position information and/or said signal intensity.