ALBE Gridded Visibility Model

摘要

The AirLand Battlefield Environment (ALBE) visibility model provides a new methodof calculating Line of Sight visibility products derived from digital terrain elevation data. This new method uses a gridded raster approach rather than the historical vector approach. The basic principles and assumptions behind the model are discussed, starting with the advantages and disadvantages of using the gridded versus a vector approach. New methods devised to handle the gridded approach are discussed, including how to determine the grid cell resolution, the spacing between individual radials, and a detailed look at determining the spacing between individual points along a radial. A new method that uses a unique step size for each individual radial is described in detail. Other features covered are the earth's curvature, the inclusion of vegetation data, the visual acuity, and an elevation matrix form to help select a precise observer location. Finally, other closely related models that are based on the basic visibility model are discussed, including How High to Visibility, Radio Frequency Loss, Visibility Probability, Line of Sight for Obstacles, Aerial Detection, and Helicopter Approach Zones.