Mattson Calculator Shortcuts:

Links from the Technology in SAR talk:
San Diego Mountain Rescue Team - http://sdmrt.org
Router firmware re-programming - http://dd-wrt.com
Team and mission management software - https://www.missionmanager.com
Offline and online maps tools for SAR - http://sartopo.com
GIS mapping interface for SAR - http://www.mapsar.net
SARApp cell phone app information - http://sarapp.com
Consensus method calculator - http://sarmath.com/consensus-category/combined
Remote aircraft controll group - http://www.multiwii.com

Critical Separation is the spacing in a grid search where, if the search objective is halfway between two searchers, the object will be at the limit of the visible range of both searchers.  This can be very useful when estimating a Probability of Detection (POD).  As with the discussion of anything related to POD, it is important to define what it is your are searching for.  You would have a different POD when searching for a responsive subject versus an unresponsive subject, or for searching during a sunny day versus a rainy night, so you would also have different critical separations for those situations.

Another way of saying critical separation is to say 100% coverage.  This is to say that every portion of the area in question was searched exactly once, with no overlap, during the search effort.  You can see from the picture below that the two searcher's visual ranges do not overlap as they search with critical separation.

The Probability of Detection associated with critical separation is defined as \( 1-e^{-1} \), which is numerically about 63%.  Many people round this down to 50% in an attempt to be conservative while reporting the POD from an assignment, although this can be unnecessarily conservative.

You found this on the internet.  Treat it appropriately.

SARMath.com is not an authority on Search & Rescue.  Many of us are affiliated with SAR teams, but not all.  Before you rely on anything during an operation, thoroughly research and test it.  Then train with it over and over.  If you would like to get involved with Search & Rescue, contact your local Agency Having Jurisdiction and ask how you can help.

Last fall I was at two Search and Rescue conferences to talk about the Mission Manager software and how it gets used for SAR.

Northwest SARCON - Friday October 4th at 15:30 and Saturday at 15:30 in Boring, Oregon.  Another great success.  Thanks to everyone who came to listen and share.  Also thanks to the organizers.  Northwest SARCON is one of my favorite conferences so far.

SAREX - Sarex was a success this past Saturday September 6th at 13:00 and Sunday at 09:00 in West Waddell State Wilderness, near Santa Cruz, California.  I'll get some answers to a few of the questions that came up posted soon.  In the meantime, have a look at the new Mission Manager page under the equally new Software Category.

Thank you for visiting SAR Math.  Stay tuned for articles about math, engineering, science and operations research and their application to Search & Rescue.