US3911597A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synthetic terrain generator
Assignee: CAE Link Corp
•
Filing: 1972-10-18
•
Granted: 1975-10-14
•
Expires: 1992-10-18
Abstract
Abstract In one aspect of the invention, the simulation of the view of the terrain from an aircraft is provided on a raster swept CRT display by the generation thereon of a grid pattern comprised of two intersecting groups of grid lines. The line of sight from an eyepoint through the screen of the display to the synthetic terrain is represented by earth direction cosine voltages. When the values of the earth direction cosine voltages are in accordance with a predetermined relationship e.g. either one of a pair of null relationships, a video signal is generated thereby providing the grid pattern in a desired perspective. In another aspect of the invention, a view of the sky and the horizon is provided at selected locations on the screen. In response to the intersection of the line of sight with points representative of the sky, a first selected shade of grey is provided at the intersected point on the screen. In response to the intersection of the line of sight with points representative of the horizon, a second selected shade of grey is provided at the intersected point on the screen.
Inventors
- 👤 Maurice Millard
- 👤 John R Trzeciak
- 👤 Brian J Woycechowsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:56
CPC Classifications
G; G09; G09B; G09B9/00; G09B9/02; G09B9/08; G09B9/30; G09B9/301; B; B64; B64D; B64D45/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
187 words
A method of simulating the view from an eyepoint in an aircraft of a grid pattern which is formed by grid lines on a synthetic terrain, said view being displayed on a viewing surface of a display unit of the type where a beam traces a raster on the viewing surface, comprising the steps of: providing an altitude signal representative of the height of said eyepoint above said terrain; providing attitude signals representative of the roll, pitch and heating of the aircraft; generating sweep signals representative of the location of said raster beam on said viewing surface; developing, from said attitude and sweep signals, earth direction cosine signals representative of a line of sight extending from said eyepoint through the location of said raster beam on said viewing surface to said synthetic terrain; generating a video pulse in response to said altitude signal, and said earth direction cosine signals concurrently having values in accordance with a null relationship which is representative of the intersection with a grid line of said line of sight; and displaying the location of said raster beam in response to said video pulse.
Claim 2
Independent Claim
187 words
A method of simulating the view from an eyepoint in an aircraft of a grid pattern which is formed by grid lines on a synthetic terrain, said view being displayed on a viewing surface of a display unit of the type where a beam traces a raster on the viewing surface, comprising the steps of: providing an altitude signal representative of the height of said eyepoint above said terrain; providing attitude signals representative of the roll, pitch and heating of the aircraft; generating sweep signals representative of the location of said raster beam on said viewing surface; developing, from said attitude and sweep signals, earth direction cosine signals representative of a line of sight extending from said eyepoint through the location of said raster beam on said viewing surface to said synthetic terrain; generating a video pulse in response to said altitude signal, and said earth direction cosine signals concurrently having values in accordance with a null relationship which is representative of the intersection with a grid line of said line of sight; and displaying the location of said raster beam in response to said video pulse.
Claim 3
Dependent Claim
60 words
The method according to claim 1 further including the steps of: providing signals representative of the velocity of the aircraft; generating translation signals representative of the time integral of said velocity; and the video pulse being generated in accordance with a null relationship which includes a line of sight from an eyepoint having a translation represented by said translation signals.
Claim 4
Independent Claim
134 words
A method of generating a synthetic terrain display for an aircraft comprising the steps of: raster scanning a viewing surface of blanked display means with a raster beam; defining a line pattern in a reference ground plane; locating an eyepoint in front of said viewing surface; defining a scanning line of sight which extends from the eyepoint through the instantaneous raster beam location on said viewing surface to said reference ground plane; electronically defining a predetermined relationship which indicates when said line of sight intersects the line pattern in said reference plane; and unblanking said display means to display the instantaneous raster beam location whenever said scanning line of sight intersects the line pattern in said reference plane, whereby a display of said line pattern in proper perspective is generated on said viewing surface.
Claim 5
Independent Claim
134 words
A method of generating a synthetic terrain display for an aircraft comprising the steps of: raster scanning a viewing surface of blanked display means with a raster beam; defining a line pattern in a reference ground plane; locating an eyepoint in front of said viewing surface; defining a scanning line of sight which extends from the eyepoint through the instantaneous raster beam location on said viewing surface to said reference ground plane; electronically defining a predetermined relationship which indicates when said line of sight intersects the line pattern in said reference plane; and unblanking said display means to display the instantaneous raster beam location whenever said scanning line of sight intersects the line pattern in said reference plane, whereby a display of said line pattern in proper perspective is generated on said viewing surface.
Claim 6
Dependent Claim
36 words
The method of claim 3 wherein said raster scanning step comprises: raster scanning a viewing surface of a blanked cathode ray tube with an electron beam; and said unblanking step comprises: unblanking said cathode ray tube.
Claim 7
Dependent Claim
53 words
The method of claim 3 wherein said step of electronically defining a predetermined relationship comprises: electronically defining a null relationship which is satisfied only when said line of sight intersects said line pattern; and detecting satisfaction of said null relationship and in response generating a signal to cause unblanking of said display means.
Claim 8
Dependent Claim
188 words
Apparatus for providing on a viewing suRface of display means a simulatd view from an eyepoint in an aircraft or the like of a synthetic terrain having a plurality of grid lines, said display means having a beam which traces a raster on said viewing surface, the apparatus being designed to receive signals representative of the altitude and velocity of an aircraft, comprising: means for generating earth direction cosine signals defining a line of sight from said eyepoint through the instantaneous beam location on said viewing surface to said synthetic terrain; and video generator means responsive to said earth direction cosine signals and signals representative of the altitude and velocity of said aircraft for electronically defining a predetermined relationship which indicates when said line of sight intersects a grid line and providing a video pulse to said display means when said earth direction cosine, altitude and velocity signals concurrently have values in accordance with said predetermined relationship, to display the instantaneous raster beam location when the line of sight therethrough intersects a grid line on said synthetic terrain, whereby said displayed raster beam locations form said simulated view.
Claim 9
Dependent Claim
188 words
Apparatus for providing on a viewing suRface of display means a simulatd view from an eyepoint in an aircraft or the like of a synthetic terrain having a plurality of grid lines, said display means having a beam which traces a raster on said viewing surface, the apparatus being designed to receive signals representative of the altitude and velocity of an aircraft, comprising: means for generating earth direction cosine signals defining a line of sight from said eyepoint through the instantaneous beam location on said viewing surface to said synthetic terrain; and video generator means responsive to said earth direction cosine signals and signals representative of the altitude and velocity of said aircraft for electronically defining a predetermined relationship which indicates when said line of sight intersects a grid line and providing a video pulse to said display means when said earth direction cosine, altitude and velocity signals concurrently have values in accordance with said predetermined relationship, to display the instantaneous raster beam location when the line of sight therethrough intersects a grid line on said synthetic terrain, whereby said displayed raster beam locations form said simulated view.
Claim 10
Dependent Claim
109 words
The apparatus of claim 5, wherein said means for generating earth direction cosine signals comprises: means for generating sweep signals representative of the instantaneous location of said raster beam on said viewing surface; means for generating aircraft direction cosine signals from said sweep signals, said aircraft direction cosine signals defining a line of sight between said eyepoint and said instantaneous raster beam location with respect to said aircraft; and transformation means responsive to said aircraft direction cosine signals and signals representative of the attitude of said aircraft for generating earth direction cosine signals therefrom, said earth direction cosine signals defining said line of sight in an earth coordinate system.
Claim 11
Dependent Claim
16 words
The apparatus of claim 6 wherein said display means comprises a raster swept cathode ray tube.
Claim 12
Dependent Claim
29 words
The apparatus of claim 8, further including means to bias said cathode ray tube below cutoff and to unblank said cathode ray tube in response to a video pulse.
Claim 13
Dependent Claim
60 words
The apparatus of claim 1 wherein said display means is located in an aircraft simulator; the signal representative of the altitude of said aircraft comprises a signal representative of the simulated height of said eyepoint above said synthetic terrain; and the signal representative of the velocity of the aircraft comprises a signal representative of the simulated velocity of said aircraft.
Claim 14
Dependent Claim
58 words
The apparatus of claim 6 wherein said video generator means comprises means for electronically defining a pair of null relationships and for providing a video pulse to display said raster beam location when said altitude signal, said velocity signal and said earth direction cosine signals concurrently have values in accordance with one of said pair of null relationships.
Claim 15
Dependent Claim
57 words
The apparatus of claim 6 wherein one of said earth direction cosine signals is a vertical earth direction cosine signal, and said video generator means additionally comprises a comparator circuit which provides a sky signal when the vertical earth direction cosine signal has a value greater than the value of a selected portion of said altitude signal.
Claim 16
Dependent Claim
60 words
The apparatus of claim 6 wherein one of said earth direction cosine signals is a vertical earth direction cosine signal, and said video generator means additionally comprises a dual comparator circuit which provides a horizon signal when the vertical earth direction cosine signal has a value intermediate to the values of a pair of selected portions of said altitude signal.
Claim 17
Dependent Claim
131 words
The apparatus of claim 6 wherein said plurality of grid lines comprises a group of north-south lines and a group of east-west lines, said earth direction cosine signals are representative of earth direction cosines respectively along a Vertical reference axis and axes parallel to said north-south and east-west grid lines, said video generator means comprising: means for providing a north-south video pulse to display said raster beam location in response to said altitude signal, said earth direction cosine signals and said velocity signal concurrently having values in accordance with a north-south null relationship; means for providing an east-west video pulse to display said raster beam location in response to said altitude signal, said earth direction cosine signals and said velocity signal concurrently having values in accordance with an east-west null relationship.
References Cited (Backward Citations)
US3098929A
Cited
US3418459A
Cited
US3060596A
Cited
US3643258A
Cited
US3439105A
Cited
US3520994A
Cited
US3605083A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |