Aircraft virtual image display system and method for providing a real-time perspective threat coverage display

Claim 1

A virtual image display system for an ownship for identifying each threat system nearby a flight path of the ownship when the ownship is within a threat range of such threat system, for generating a three-dimensional threat envelope for each identified threat system, and for displaying real-time perspective video images of such three-dimensional threat envelope for viewing by a pilot of the ownship, comprising: a video display subsystem for generating and displaying video images to the ownship pilot; means for sensing the attitude and position of the head of the ownship pilot in relation to an ownship cockpit coordinate system; a digital terrain database for providing topographical data and information with respect to terrain proximal the flight path of the ownship; database means for providing geographical coordinate, elevation, and characteristics data with respect to threat systems proximal the flight path of the ownship; database means for providing navigational data and dynamic state information with respect to the ownship; and computer processing means functionally interconnected to said threat systems database means and said navigational data/dynamic state information database means and operative for identifying each threat system nearby the flight path of the ownship when the ownship is within a threat range of the threat system, wherein said computer processing means is operative to identify the threat system by determining a current position and a short-term projected flight path of the ownship, by correlating said current position and said short-term projected flight path of the ownship with geographical coordinates of the threat system to determine whether the threat system is proximal said current position and said short-term projected flight path of the ownship, and determining whether the ownship is within the threat range of the threat system; said computer processing means being functionally interconnected to said video display subsystem, said attitude/position sensing means, said digital terrain database, said threat systems database means, and said navigational data/dynamic state database means and operative for generating a three-dimensional threat envelope for said identified threat system, wherein said computer processing means is operative to generate said three-dimensional threat envelope for said identified threat system by defining a two-dimensional plan view of said three-dimensional threat envelope, by defining terrain profiles for said two-dimensional plan view, by identifying a terrain profile grazing line for each of said terrain profiles, by defining an endpoint for each said terrain grazing profile, and by connecting said endpoints of adjacent ones of said terrain grazing lines by a boundary line wherein said terrain grazing lines and said boundary lines in combination form a set of interconnected polygons emanating from said identified threat system that define said three-dimensional threat envelope; said computer processing means being functionally interconnected to said video display subsystem, said attitude/position sensing means, said digital terrain database, said threat systems database means, and said navigational data/dynamic state database means and operative for displaying real-time perspective video images of each said generated three-dimensional threat envelope for viewing by the ownship pilot.

Claim 6

A method for providing threat information to a pilot of an ownship flying a flight path by means of a video display subsystem, comprising the steps of: (202) identifying each threat system proximal the flight path of the ownship when the ownship is within a threat range of the threat system, said threat system identification step includes the substeps of (202A) determining a current position and a short-term projected flight path of the ownship, (202B) correlating said current position and said short-term projected flight path of the ownship with geographical coordinates of the threat system to determine whether the threat system is proximal said current position and said short-term projected flight path of the ownship; and (202C) determining whether the ownship is within the threat range of the threat system; (204) generating a three-dimensional threat envelope of each said identified threat system, said three-dimensional threat envelope generating step including the substep of (204A) defining a two-dimensional plan view of said three-dimensional threat envelope, (204B) defining terrain profiles for said two-dimensional plan view, (204C) identifying a terrain grazing line for each of said terrain profiles, (204D) defining an endpoint for each said terrain grazing profile, and (204E) connecting said endpoints of adjacent terrain grazing lines by a boundary line wherein said terrain grazing lines and said boundary lines in combination form a set of interconnected polygons emanating from said identified threat system that define said three-dimensional threat envelope; (206) storing each said generated three-dimensional threat envelope in a computer memory cache; (208) determining, for each said stored three-dimensional threat envelope, whether any portion thereof is within a system field of view of the ownship; (220) returning to step (202) if it is determined in step (208) that no portion of said three-dimensional threat envelope is within said system field of view; (212) displaying a perspective video image of said portion of said three-dimensional threat envelope for viewing by the pilot of the ownship by means of the video display subsystem; and (216) repeating steps (204), (206), (208), and (212) as required to display a continuous series of real-time perspective video images of said threat envelope for viewing by the pilot of the ownship by means of the video display subsystem.

Claim 7

A method for providing threat information to a pilot of an ownship flying a flight path by means of a video display subsystem, comprising the steps of: (202) identifying each threat system proximal the flight path of the ownship when the ownship is within a threat range of the threat system, said threat system identification step includes the substeps of (202A) determining a current position and a short-term projected flight path of the ownship, (202B) correlating said current position and said short-term projected flight path of the ownship with geographical coordinates of the threat system to determine whether the threat system is proximal said current position and said short-term projected flight path of the ownship; and (202C) determining whether the ownship is within the threat range of the threat system; (204) generating a three-dimensional threat envelope of each said identified threat system, said three-dimensional threat envelope generating step including the substep of (204A) defining a two-dimensional plan view of said three-dimensional threat envelope, (204B) defining terrain profiles for said two-dimensional plan view, (204C) identifying a terrain grazing line for each of said terrain profiles, (204D) defining an endpoint for each said terrain grazing profile, and (204E) connecting said endpoints of adjacent terrain grazing lines by a boundary line wherein said terrain grazing lines and said boundary lines in combination form a set of interconnected polygons emanating from said identified threat system that define said three-dimensional threat envelope; (206) storing each said generated three-dimensional threat envelope in a computer memory cache; (208) determining, for each said stored three-dimensional threat envelope, whether any portion thereof is within a system field of view of the ownship; (220) returning to step (202) if it is determined in step (208) that no portion of said three-dimensional threat envelope is within said system field of view; (212) displaying a perspective video image of said portion of said three-dimensional threat envelope for viewing by the pilot of the ownship by means of the video display subsystem; and (216) repeating steps (204), (206), (208), and (212) as required to display a continuous series of real-time perspective video images of said threat envelope for viewing by the pilot of the ownship by means of the video display subsystem.