System, method and apparatus for searching geographic area using prioritized spatial order

• US 7,698,058 B2
• Filed: 12/27/2007
• Issued: 04/13/2010
• Est. Priority Date: 01/07/2003
• Status: Active Grant

• Current Assignee: Garmin International, Inc. (Garmin Limited)
• Original Assignee: Garmin International, Inc. (Garmin Limited)
• Inventors: Barber, Clayton E., Chen, Susan S.
• Primary Examiner(s): To; Tuan C
• Application Number:
  US11/965,525
• Publication Number:
  US 20080103691A1
• Time in Patent Office: 838 Days
• Field of Search: 701/207, 701/9, 701/301, 340/963, 340/970, 340/988, 340/971, 340/961, 340/945, 375/240.16, 382/236, 348/416.1, 342/65, 342/26.R, 342/195, 342/38, 342/104
• US Class Current: 701/207
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence

Abstract

A spatial data search method, system and apparatus for identifying particular data of significance around a reference vector through the spatial data. The method involves determining a reference vector within a spatial region for which spatial data exists, loading a portion of the spatial data including the data around the reference vector into a memory buffer, and searching the spatial data in a prioritized order. The method, system and apparatus have particular utility in searching geographic data for a terrain awareness and warning system (“TAWS”) and display in an aircraft. Embodiments of the present invention provide advantages over existing sequential and radial search methods, significantly reducing the processing and calculations required and providing faster alerts to pilots.

Claims

1. A terrain awareness and warning system (TAWS) for an aircraft, the TAWS comprising:

a terrain information database configured to store a plurality of data cells corresponding to elevation information for a terrain region;

a terrain buffer configured to receive and store data cells corresponding to a portion of the terrain region;

a look-ahead warning generator configured to receive indications of terrain clearance alerts and communicate the indications by at least one of a visual display and an aural warning; and

a processor coupled to each of the terrain information database, the terrain buffer, and the look-ahead warning generator, the processor configured to—

identify a search vector based at least upon a position of the aircraft and a velocity of the aircraft,

search the data cells stored within the terrain buffer in a predetermined prioritized order to compare a projected altitude of the aircraft with the elevation information associated with the searched cells, and

based on the comparison, provide an indication of a terrain clearance alert to the look-ahead warning generator,

wherein the predetermined prioritized order includes searching at least a first cell on the search vector, then searching at least a second cell adjacent the search vector, and then searching at least a third cell on the search vector ahead of the first cell.

2. The TAWS of claim 1, wherein the processor is further operable to select data cells from the terrain information database for storage within the terrain buffer based on the identified search vector.

3. The TAWS of claim 1, wherein the search vector is identified based on the position of the aircraft, the velocity of the aircraft, and a projected flight path of the aircraft.

4. The TAWS of claim 1, wherein the predetermined prioritized order includes—

searching a first plurality of cells on the search vector, where the first cell is a first one of the first plurality of cells,

then searching at least the second cell, where the second cell is adjacent the search vector and the first cell,

then searching at least the third cell, where the third cell is ahead of each of the first plurality of cells, and

then searching at least a fourth cell which is adjacent the search vector and the second or third cell.

5. The TAWS of claim 1, wherein the processor is further configured to monitor movements of the aircraft and responsively modify the predetermined prioritized order.

6. The TAWS of claim 1, wherein the processor is further configured to provide data to the visual display representing the elevation information for the terrain region in relation to a flying altitude of the aircraft for display in conjunction with the terrain clearance alerts.

7. The TAWS of claim 1, wherein the processor is further operable to, based on the comparison of the projected altitude of the aircraft with the elevation information associated with the searched cells, store identifiers corresponding to one or more of the searched cells in an alert list and provide the indication of the terrain clearance alert to the look-ahead warning generator based on the contents of the alert list.

8. A terrain awareness and warning system (TAWS) for an aircraft, the TAWS comprising:

a terrain information database configured to store a plurality of data cells corresponding to elevation information for a terrain region;

a terrain buffer configured to receive and store data cells corresponding to a portion of the terrain region;

a look-ahead warning generator configured to receive indications of terrain clearance alerts and communicate the indications by at least one of a visual display and an aural warning; and

a processor coupled to each of the terrain information database, the terrain buffer, and the look-ahead warning generator, the processor configured to—

identify a search vector based at least upon a position of the aircraft and a projected flight path of the aircraft,

search the data cells stored within the terrain buffer in a predetermined prioritized order to compare a projected altitude of the aircraft with the elevation information associated with the searched cells,

based on the comparison, store identifiers corresponding to one or more of the searched cells in an alert list, and

provide an indication of a terrain clearance alert to the look-ahead warning generator based on the contents of the alert list,

wherein the predetermined prioritized order includes—

searching a first plurality of cells on the search vector, where a first cell is a first one of the first plurality of cells,

then searching at least a second cell, where the second cell is adjacent the search vector and the first cell,

then searching at least a third cell, where the third cell is on the search vector and ahead of each of the first plurality of cells, and

then searching at least a fourth cell which is adjacent the search vector and the second or third cell.

9. The TAWS of claim 8, wherein the processor is further operable to select data cells from the terrain information database for storage within the terrain buffer based on the identified search vector.

10. The TAWS of claim 8, wherein the processor is further configured to monitor movements of the aircraft and responsively modify the predetermined prioritized order.

11. The TAWS of claim 8, wherein the processor is further configured to provide data to the visual display representing the elevation information for the terrain region in relation to a flying altitude of the aircraft for display in conjunction with the terrain clearance alerts.

12. A method of providing a terrain warning for an aircraft using a terrain awareness and warning system (TAWS), the method comprising:

accessing with the TAWS a terrain buffer including a plurality of data cells corresponding to elevation information for a portion of a terrain region;

identifying with the TAWS a search vector based at least upon a position of the aircraft and a velocity of the aircraft;

searching with the TAWS the data cells stored within the terrain buffer in a predetermined prioritized order to compare a projected altitude of the aircraft with the elevation information associated with the searched cells; and

based on the comparison, provide with the TAWS an indication of a terrain clearance alert,

wherein the predetermined prioritized order includes searching at least a first cell on the search vector, then searching at least a second cell adjacent the search vector, and then searching at least a third cell on the search vector ahead of the first cell.

13. The method of claim 12, further including selecting data cells from a terrain information database for storage within the terrain buffer based on the identified search vector.

14. The method of claim 12, wherein the search vector is identified based on the position of the aircraft, the velocity of the aircraft, and a projected flight path of the aircraft.

15. The method of claim 12, wherein the predetermined prioritized order includes—

searching a first plurality of cells on the search vector, where the first cell is a first one of the first plurality of cells,

then searching at least the second cell, where the second cell is adjacent the search vector and the first cell,

then searching at least the third cell, where the third cell is ahead of each of the first plurality of cells, and

then searching at least a fourth cell which is adjacent the search vector and the second or third cell.

16. The method of claim 12, further including monitoring movements of the aircraft and responsively modifying the predetermined prioritized order.

17. The method of claim 12, further including, based on the comparison of the projected altitude of the aircraft with the elevation information associated with the searched cells, storing identifiers corresponding to one or more of the searched cells in an alert list and providing the indication of the terrain clearance alert based on the contents of the alert list.