Geometric Algorithms for Siting of Air Defense Missile Batteries


				by

		    Prof Wm Randolph Franklin
       Electrical, Computer, and Systems Engineering Dept.
		Rensselaer Polytechnic Institute,

			 LTC Clark K. Ray
			    EECS Dept.
		       US Military Academy,
			  West Point, NY

		       Prof Shashank Mehta
			    ECSE Dept.
		Rensselaer Polytechnic Institute,

			       for

		   Battelle, Columbus Division
		 Contract Number DAAL03-86-D-0001
		    Delivery Order Number 2756
		   Scientific Services Program

			  March 31, 1994


Abstract

Geometric aspects of the visibility problem in the siting of air
defense missile batteries were studied in this project. It
theoretically analyzed the problem, produced several new and
efficient algorithms, implemented them, and tested them on many
cells of data. The theoretical analysis studied the terrain
characteristics, formally defined the Hawk siting problem,
formalized the optimal placement of observers, and considered the
minimum elevation of an airplane flying over varying
terrain. Three algorithms for finding the viewshed around a
particular observer were studied. R3 is slow but accurate. R2 is
much faster, yet almost as accurate. Xdraw computes an approximate
viewshed with error bounds. Four visibility index algorithms were
studied. VL runs a fixed number of lines of sight out from every
possible observer. WeightF weights the points by distance. Weight
approximates WeightF, and DEM/LOS skips points along each line of
sight for increased speed. The visibility indices of 20 DTED level
I cells of the Korean peninsula, totaling over 28 million points,
were processed with VL. Experimentally, visibility index is not
strongly correlated with elevation. A PC-based demonstration
program with this data was exhibited to the user community. The
accuracy was compared on data ranging from Korea to Dijon and
Pripyat', showing that these methods do select the
highest-visibility points.

Keywords: line of sight, visibility index, viewshed, siting, air
defense, geometry, Digital Terrain Elevation Data.

Acknowledgement: This work was supported by the US Army
Topographic Engineering Center (Mr. John R Benton) under the
auspices of the US Army Research Office Scientific Services
Program administered by Battelle (Delivery Order 2756, Contract
No. DAAL03-86-D-0001.