초록 ▼

A convergence model is shown and described for accommodating variation in data post spacing in a digital terrain elevation database (DTED) based on longitude and latitude address values for data posts. Under such a database structure, data posts lying along lines of latitude vary in spacing accordin

A convergence model is shown and described for accommodating variation in data post spacing in a digital terrain elevation database (DTED) based on longitude and latitude address values for data posts. Under such a database structure, data posts lying along lines of latitude vary in spacing according to latitude, and converge at the poles with zero spacing therebetween. To scan a circular region of data posts relative to a given data post, e.g., a threat installation, this variation in data post spacing is considered by appropriately scaling sample step spacing along radials traversed in executing a radial spoke scan pattern. In this manner, a circular region of data posts surrounding a given data post may be sampled using simple, dedicated hardware despite this variation in data post spacing.

대표청구항 ▼

A method of providing intervisibility calculations for known terrain using a computer comprising the steps of: providing a digital terrain elevation data (DTED) database which models the known terrain and has data posts corresponding to points on the known terrain, the data posts being individually

A method of providing intervisibility calculations for known terrain using a computer comprising the steps of: providing a digital terrain elevation data (DTED) database which models the known terrain and has data posts corresponding to points on the known terrain, the data posts being individually addressable in X and Y dimensions wherein spacing between adjacent terrain points varies as a function of at least one of said X and Y dimensions; identifying a threat data post by X and Y dimension values; identifying a set of radials of length corresponding to said constant radius and emanating from said threat data post; dividing said at least one of said X and Y dimensions into a plurality of sub-zones and for each sub-zone identifying a data post spacing value in said X and Y dimensions corresponding to terrain point spacing therein; traversing at least one of said radials by identifying a plurality of delta X and delta Y value pairs based on an angular orientation of said at least one radial, said plurality of delta X and delta Y value pairs are scaled according to said plurality of sub-zones, further identifying a given delta X and delta Y value pair from said plurality of sub-zones according to said threat post X and Y dimension values, and successively sampling along said at least one radial by successively accumulating said given delta X and delta Y values to identify successive sample points along said at least one radial whereby sampling at a given number of said successive sample points provides sampling along said at least one radial to said given length; and calculating intervisibility of the sample points with respect the threat point.