Multilateration system and method

• US 8,232,913 B2
• Filed: 02/07/2012
• Issued: 07/31/2012
• Est. Priority Date: 04/26/2008
• Status: Expired due to Fees

• Current Assignee: ROKE Manor Research Limited (Chemring Group PLC)
• Original Assignee: ROKE Manor Research Limited (Chemring Group PLC)
• Inventors: Weedon, Robert John
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US13/367,538
• Publication Number:
  US 20120127015A1
• Time in Patent Office: 175 Days
• Field of Search: 342/27, 342/28, 342 29- 51, 342/59, 342/118, 342/123, 342/125, 342/126, 342/145, 342/175, 342/195, 342385-416, 342450-465, 73/73, 367/118, 375/259
• US Class Current: 342/126
• CPC Class Codes: G01S 13/723 by using numerical data
• CPC Class Codes: G01S 13/781 Secondary Surveillance Radar [SSR] in general

Abstract

A multilateration system and method includes a plurality of receiver stations for receiving signals from an aircraft, and a controller that derives the position of the aircraft by applying a multilateration process to outputs from the receiver stations. For this purpose, the controller determines the altitude of the aircraft and selects a multilateration process that is to be used for position determination, based on the determined altitude.

Claims

1. A multilateration system comprising:

a plurality of receiver stations configured to receive aircraft signal data; and

a controller configured to derive aircraft positional data by applying a multilateration process to at least some of the aircraft signal data, wherein the controller is configured to

i) determine an altitude associated with the aircraft signal data;

ii) choose a multilateration process based on the determined altitude; and

iii) perform the chosen multilateration process to determine an aircraft position.

2. The system of claim 1, wherein the controller is configured to perform the multilateration process using the aircraft signal data and the determined altitude.

3. The system of claim 1, wherein the controller is configured to:

use the aircraft signal data to create aircraft track data; and

store the aircraft track data to a memory.

4. The system as claimed in claim 3, wherein the aircraft track data comprises at least one of a mode type indicator, a mode code, and a position.

5. The system as claimed in claim 3, wherein the controller comprises a locator having logic configured to:

compare i) the determined aircraft position provided by the chosen multilateration process with ii) a predicted aircraft position extrapolated from the aircraft track data; and

update the aircraft track data stored in the memory with the determined aircraft position if the comparison is within a certain threshold.

6. The system of claim 1, wherein the controller comprises a locator having control logic configured to:

i) determine a number of the receiver stations that provide the aircraft signal data to the controller,

ii) determine from the aircraft signal data a geometry of the receiver stations that provide the aircraft signal data to the controller,

iii) determine whether the geometry will support a three dimensional multilateration,

iv) perform the three dimensional multilateration if the geometry is determined to support the three dimensional multilateration; and

v) perform a two dimensional or two dimensional augmented multilateration if the geometry is not determined to support the three dimensional multilateration.

7. An air-traffic control system comprising:

a multilateration system that includes;

a plurality of receiver stations configured to receive aircraft signal data, and

a controller configured to derive aircraft positional data by applying a multilateration process to at least some of the aircraft signal data, wherein the controller is configured to

i) determine an altitude associated with the aircraft signal data,

ii) choose a multilateration process based on the determined altitude, and

iii) perform the chosen multilateration process to determine an aircraft position; and

a tracker system configured to display to a system operator aircraft track data provided by the chosen multilateration system.

8. A multilateration method comprising:

receiving an aircraft code at a plurality of receiver stations; and

deriving aircraft positional data by applying a multilateration process to the received aircraft code, wherein the deriving includes;

determining an altitude associated with the received aircraft code;

choosing a multilateration process based on the determined altitude; and

performing the chosen multilateration process to determine an aircraft position.

9. The method of claim 8 wherein the determined altitude is a barometric altitude obtained from the received aircraft code.

10. A method of claim 8, wherein the choosing of the multilateration process comprises comparing the determined altitude with one or more threshold values to determine the multilateration process.

11. A method of claim 8, further comprising:

storing data associated with the received aircraft code as aircraft track data in a memory.

12. The method of claim 11, further comprising:

comparing the determined aircraft position provided by the chosen multilateration process with an extrapolated position from the aircraft track data; and

updating the aircraft track data in the memory with the determined aircraft position if the comparison results in a match.

13. The method of claim 8, further comprising:

displaying the determined aircraft position to an operator.