Apparatus and method for an aircraft navigation system having improved mission management and survivability capabilities

• US 5,086,396 A
• Filed: 02/19/1991
• Issued: 02/04/1992
• Est. Priority Date: 02/02/1989
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Waruszewski, Harry L. Jr.
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/657,275
• Time in Patent Office: 350 Days
• Field of Search: 364/448, 364/449, 364/443, 364/460, 364/454, 364/461, 340/990, 340/995
• US Class Current: 701/221
• CPC Class Codes: F41G 7/343 comparing observed and stored data of target position or of distinctive marks along the path towards the target
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G05D 1/106 Change initiated in response to external conditions, e.g. avoidance of elevated terrain or of no-fly zones

Abstract

An aircraft navigation system is disclosed for use in missions involving unfamiliar terrain and/or terrain having hostile forces. The navigation system includes an inertial navigation system, a map of the terrain with elevational information stored in a digitized format as function of location, a typical energy managed or narrow (radar or laser) beam altimeter, a display system, and a central processing unit for processing data according to preselected programs. The data processing system includes an operational mode (software program) for relating the continuing sequence of altimeter readings with the changing aircraft position on the digitized map. In this manner, the true position of the aircraft can be determined with respect to the digitized map and can be displayed on a plan view of the map. When the correct position of the aircraft with respect to the digitized map is known, a display of the map and the aircraft can provide presentations useful to the navigation of the aircraft, e.g., by displaying surface features that can provide potential danger for the aircraft. The correct position of the aircraft with respect to the digitized map can permit the aircraft to engage in terrain following procedures using only the relatively difficult to detect altitude range finding apparatus as a source of emitted electromagnetic radiation. The navigation system, in conjunction with information regarding hostile antiaircraft facilities, can provide a display permitting an operator to determine a reduced risk flight path.

Claims

1. A navigation system for use in aircraft, said navigation system comprising:

an inertial navigation system;

a data base including a terrain map with digitized terrain elevations as a functions of global coordinates;

a directional distance apparatus measuring a distance between an aircraft and terrain over which said aircraft is flying;

processor means responsive to said inertial navigation system and to said terrain map for determining an approximate position of said aircraft relative to said terrain map, said processor means responsive to terrain map profiles of said terrain map in said approximate position of said aircraft relative to said terrain map and to terrain profiles measures by said directional distance apparatus for identifying a current position of said aircraft relative to said terrain map, said processor means identifying selected features of said terrain map which have a predetermined relationship with said aircraft; and

a monitor unit responsive to said processor means for displaying said current position of an aircraft relative to a portion of said terrain map, said monitor means displaying said selected features located on said terrain map portion.

2. The navigation system of claim 1 wherein said processor means processes said digitized terrain map to provide a profile view of terrain in a flight path of said aircraft as viewed from a position of said aircraft icon on said terrain map, said profile view being displayed on said monitor unit.

3. The navigation system of claim 1 wherein said monitor unit provides a display selected from the group of displays consisting of a profile of terrain contours visible from the flight deck of said aircraft, each display of said group of displays being provided by said processor means in response to said digitized terrain map and a position of said aircraft relative to said digitized terrain map.

4. The navigation system of claim 1 wherein said monitor unit displays threats from antiaircraft installations for a current altitude of said aircraft for a position of said aircraft relative to said digitized terrain map, a display of said threats being determined by said processing means.

5. The navigation system of claim 4 wherein said monitor unit provides an intervisibility display of threats to said aircraft from known hostile installation relative to said aircraft icon, said intervisibility display including terrain masking for said current altitude of said aircraft.

6. The navigation system of claim 5 wherein a first color designates terrain structures having an altitude as high or higher than a current altitude of said aircraft.

7. The navigation system of claim 1 wherein said monitor unit displays threats to a flight path on said terrain map relative to said aircraft icon in a plurality of colors, each of said colors identifying a parameter of threats relative to said aircraft.

8. The navigation system of claim 1 wherein said processor means includes means for providing sum angle shadowing on a terrain map displayed by said monitor unit.

9. The method of assisting navigation of an aircraft on a mission, said method comprising the steps of:

by means of navigational equipment, identifying an approximate position of said aircraft relative to a terrain map, said terrain map having at least digitized terrain elevations stored as a functions of global coordinates;

comparing terrain profiles determined by measurements of a distance of said aircraft from terrain over which said aircraft is flying with terrain map profiles to determine a position of said aircraft relative to said terrain map;

displaying a presentation of a local region of said terrain map with an icon of said aircraft positioned on said presentation in said position of said aircraft relative to said terrain map; and

implementing said presentation to provide a visual indication of terrain map features which currently provide a threat to aircraft security.

10. The method of assisting navigation of claim 9 wherein said comparing and said displaying steps reduce uncertainties in a position of said aircraft relative to features of said digitized terrain map resulting from global coordinate identification of said aircraft position and global coordinate identification of said terrain map feature positions.

11. The method of assisting navigation of claim 10 wherein said implementing step includes a step of providing said presentation with a visual indication of regions of safety from antiaircraft armament relative to a current position of said aircraft.

12. The method of assisting navigation of claim 10 wherein said implementing step includes a step of providing said presentation with a visual indication of a profile view of terrain features in a flight path of said aircraft relative to a current position of said aircraft.

13. The method of assisting navigation of claim 10 wherein said implementing step includes a step of providing said presentation with a visual indication of terrain features in front of said aircraft as viewed from a flight deck of said aircraft.

14. The method of assisting navigation of claim 10 wherein said implementing step includes a step of providing said presentation with a visual geographical features providing a threat to said aircraft as a result of present flight parameters of said aircraft.

15. A navigation system for assisting operators of an aircraft in executing complex mission objectives in hostile territory, said navigation system comprising:

an aircraft-to-terrain distance measuring device;

a terrain map storing digitized terrain elevation data as a function of terrain map coordinates, said terrain map including threats to said aircraft;

a terrain aided navigation system coupled to said distance measuring device and to said terrain map for determining a position of said aircraft relative to said terrain map coordinates by comparing terrain profiles measured by said aircraft-to-terrain distance measuring device to terrain profiles of said terrain map; and

a display unit coupled to said terrain aided navigation system and to said terrain map for displaying an icon of said aircraft on a presentation of a region of said terrain map, an icon location being determined by said terrain aided navigation system, said presentation including visual indications of threats to said aircraft in a neighborhood of a flight path of said aircraft.

16. The navigation system of claim 15 wherein said presentation includes a location of at least one antiaircraft installation, said presentation providing a visual presentation of regions wherein said antiaircraft installation threatens said aircraft when said aircraft is flying at an altitude of said aircraft using said navigation system.

17. The navigation system of claim 15 wherein said presentation includes a profile view of terrain features in a flight path of said aircraft relative to a current position of said aircraft.

18. The navigation system of claim 15 wherein said presentation includes a view of terrain features in front of said aircraft as viewed from a flight deck of said aircraft.

19. The navigation system of claim 15 wherein said terrain aided navigation system used with said terrain map reduces an uncertainty in a position of said aircraft relative to said threats resulting from a use of global coordinates to identify positions of said threats and said aircraft.

20. The navigation system of claim 15 wherein said presentation includes sun angle shadowing of terrain features.