
Accession Number : AD0654382
Title : AN OPTIMUM SEARCH IN RANGE AND RANGE RATE,
Corporate Author : JOHNS HOPKINS UNIV SILVER SPRING MD APPLIED PHYSICS LAB
Personal Author(s) : Schwab,V.
Report Date : 26 SEP 1960
Pagination or Media Count : 23
Abstract : Signals from a target being tracked in range (x) and range rate (y) are lost (as a result of noise or jamming) at t = O. At time t = t sub o signals are again available and a search can be undertaken to reacquire the target whose coordinates are assumed to be given by the equations, x sub T = u sub T + v sub T t and y sub T = v sub T. In formulating the search problem the unknown constants u sub T and v sub T are replaced by the stationary random variables u and v which have a known joint probability density distribution, rho(u, v). The nonstationary random variable, x, and the stationary random variable, y, are then defined in terms of u, v and t by the equations, x = u + vt and y = v. A search for the target, either in the xyplane for the moving point (x sub T, y sub T) or in the uvplane for the fixed point (u sub T, v sub T), is said to be optimum if the target is found in the least time possible or, what is equivalent, if the mean cumulative acquisition time is a minimum. In this report the optimum search in the uvplane is obtained for an arbitrary distribution, rho(u, v). Also, an example of the optimum search is offered for the case where u and v are independent random variables with normal probability density distributions. The example includes the optimum searches in the uv and xyplanes.
Descriptors : (*TARGETS, SEARCH THEORY), (*POSITION FINDING, TARGETS), RANDOM VARIABLES, PROBABILITY, MAPPING(TRANSFORMATIONS), OPTIMIZATION, STATISTICAL ANALYSIS, INTEGRAL EQUATIONS, MATHEMATICAL ANALYSIS
Subject Categories : Statistics and Probability
Active & Passive Radar Detection & Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE