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https://github.com/tvrusso/sar_nomographs

A handful of simple nomographs for computing Probability of Detection using the Law of Random Search
https://github.com/tvrusso/sar_nomographs

effort estimate nomogram-visualization pdf-versions pod probability-of-detection pynomo search-theory sweep-width

Last synced: 12 months ago
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A handful of simple nomographs for computing Probability of Detection using the Law of Random Search

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README 

          
# SAR_Nomographs



This is a collection of hacks I created using

[PyNomo](http://lefakkomies.github.io/pynomo-doc/index.html).  Pynomo is also now on github at

its author's repository, https://github.com/lefakkomies/pynomo.



The purpose is to provide a simple, usable set of nomographs that

search planners and debriefers can use to estimate Probability of Detection

(POD) or the effort required to achieve a given POD, without having to pull

out a computer and spreadsheet program to do so.



In order to generate the nomographs from the scripts (or hack on them), you

must first install PyNomo and all of its dependencies according to

the directions on its web site.  Once PyNomo is installed properly,

you can just run these scripts to produce the nomographs.  The scripts

produce PDFs of the nomographs for viewing in any PDF viewer or

incorporation into other documents.



The repository contains PDF versions of the nomographs as generated by the

python scripts, so you don't have to unless you want to hack on 'em.



The two nomographs that are intended to be used are

POD_from_W_v_t_simplified.pdf and POD_from_W_L_N.pdf.  The others are

all just toys I created while learning PyNomo and building these two.



POD_from_W_v_t_simplified.pdf is intended for planning purposes, and

instructions for using it are in "PlanningNomograph_Instructions.odt",

a LibreOffice document.  It can be used to estimate the searcher

effort (in "searcher-hours") required to achieve a given POD, knowing

either the effective sweep width or the measured average range of

detection, the searcher speed and region area and desired POD.

Alternatively, it can be used to determine the attainable POD using a

given level of effort (in searcher-hours).



Conversion between range of detection and sweep width makes use of the

approximate relations described in [Use of the Visual Range of

Detection to Estimate Effective Sweep Widths for Land Search and

Rescue Based on 10 Detection Experiments in North

America](http://www.wemjournal.org/article/S1080-6032%2813%2900266-4/abstract).



The second nomograph, POD_from_W_L_N.pdf, is for debriefing purposes.

It allows the debriefer to compute the POD of a completed search using

the measured average range of detection (or alternatively the

tabulated effective sweep width), the total track length of one

searcher in the team (as measured by GPS), the number of searchers on

the team, and the area searched.  Instructions for using it are in

"DebriefNomograph_Instructions.odt" (also a LibreOffice document).



PDF versions of both instruction sheets are also present in the

repository, for those who cannot read LibreOffice documents.



These nomographs were created first as a little joke I was going to

present to a class on search theory at the 2015 New Mexico search and

rescue conference, ESCAPE, showing how search planners of the 1940s

might have computed the quantities in question.  Then it occurred to

me that the nomograph would actually be useful even to search planners

in the 21st century.  Effective use of these nomographs does require

familiarity with search theory and its application.  I drafted a tiny

web page with some useful papers and books to read if you're

interested in this subject.  It's at

http://pages.swcp.com/~russo/searchtheoryrefs.html.