Accession Number : ADA112481

Title :   A Result in the Theory of Spiral Search.

Descriptive Note : Professional paper,


Personal Author(s) : Nunn,Walter R

PDF Url : ADA112481

Report Date : Mar 1980

Pagination or Media Count : 16

Abstract : This note presents a result in the theory of spiral search which does not seem to be available in the literature in spite of its straightforward derivation and obvious applicability in certain types of 'real life' search problems. The result gives the probability of detection as a function of time for a class of prior distributions of search-object, i.e. target, position centered at the origin of the x,y plane. We restrict attention to a spiral-type search in which the searcher covers the AOU(area of uncertainty) in concentric rings, moving out from the center. In the common case that the prior density is circular normal, the time to detection is seen to be approximately exponentially distributed. This is a somewhat counter-intuitive result in that the detection rate is constant, since it would appear that detection rate must decrease with time as the searcher moves from high probability areas to low probability areas.

Descriptors :   *Target detection, *Searching, *Flight paths, Position finding, Probability, Time, Distribution, Rings, Circles, Flight speed indicators, Variable coordinates

Subject Categories : Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE