초록 ▼

A method for presenting intervisibility data relative to an observation point. A data base of terrain altitudes is stored in computer memory. The data base comprises terrain altitudes at a grid of points in a selected terrestrial area encompassing the observation point. Visible heights from the obse

A method for presenting intervisibility data relative to an observation point. A data base of terrain altitudes is stored in computer memory. The data base comprises terrain altitudes at a grid of points in a selected terrestrial area encompassing the observation point. Visible heights from the observation point at the grid points are derived from the data base with a computer by performing a number of steps grid point by grid point in succession in an order moving away from the observation point. The first step is to determine a projected height at the grid point from the visible heights between the observation point and the grid point. The second step is to compare the projected height with the terrain altitude at the grid point. The third step is select as the visible height at the grid point the larger of the compared terrain altitude and the projected height. A number representative of the visible height at each grid point as so derived with a computer is stored in computer memory. The computer memory is coupled to a visual display device to present the stored representations of the visible height in spatial relationship coordinated with the spatial relationship of the grid points of the terrestrial area. The visible height data is derived by use of the similar triangles theorem, and interpolation of previously calculated visible heights.

대표청구항 ▼

A method for presenting intervisibility data relative to an observation point comprising the steps of: storing in a computer memory a data base of terrain altitudes at a grid of points in a selected terrestrial area encompassing the observation point; deriving from said data base visible heights fro

A method for presenting intervisibility data relative to an observation point comprising the steps of: storing in a computer memory a data base of terrain altitudes at a grid of points in a selected terrestrial area encompassing the observation point; deriving from said data base visible heights from the observation point at the grid points by performing, grid point by grid point in succession in an order moving away from the observation point, using a computer, the steps of: (a) determining, from the visible heights between the observation point and the grid point, a projected height at the grid point; (b) comparing the projected height with the terrain altitude at the grid point; and (c) selecting, as a visible height at the grid point, the larger of the compared terrain altitude and projected height; storing representations of the visible heights in computer memory; and coupling said computer memory to a visual display device to present the stored representations in spatial relationship coordinated with the spatial relationship of the grid points of the terrestrial area.