Computers in Search Planning

Computers can be a great aid in search planning. Used properly with the right software they can greatly simplify data handling and probability calculations, and help to provide efficient search control and the basis for factual decision making.

In search planning, computers can be used for:

• Graphical representation of intelligence and search data using a Geographic Information System (GIS).
• Record keeping, such as clue logs, radio logs, running sheets, etc.
• Search probability calculations.

The computer can be almost any type of computer but typically the most common would be a laptop or notebook computer being operated at the field search headquarters, or forward command point. This puts the computer as close to the field as practical, and facilitates collection and collation of data from search teams (via their GPS's) and the ability to rapidly update the search plan and deploy the search teams appropriately.

When operating a computer in the field consider using a 12V battery supply and the appropriate auto air adapter for the laptop. This will provide a quiet, reliable power supply, free of voltage fluctuations typical from generators. The battery(ies) can be changed and taken elsewhere for re-charging as required. Another consideration for the field search HQ should be the provision of a portable printer for the computer. With a printer, maps can be produced from the computer showing sector boundaries, and with search intelligence (such as hazards, attractions, passes, barriers, water sources, shelter, etc) shown on the map to supplement the topographic maps the search teams will use.

Geographic Information Systems (GIS)

There are many Geographic Information Systems available from small inexpensive programs, to software that costs many thousands of dollars. Full blown GIS software such as MapInfo and ArcView will do everything required for search planning. There are other smaller packages which are much less expensive, and will do much of what is required for search planning, with perhaps a little less convenience. Like all equipment choices, you need to make the choice based on needs, wants and budget.

One such low cost package suitable for handling search intelligence information is OziExplorer. The author has reasonably extensive experience using OziExplorer both for search intelligence and recreational mapping and GPS navigation. With a little ingenuity, it works well for collecting search intelligence and operational information.

Search Probability Calculations

There are lots of software packages available for performing search calculations, from commercial packages to freeware. While having a computer to do the number crunching is great, remember to have back up manual systems should the computer fail for whatever reason.

SARCalc is an MS Excel workbook for performing Probability Calculations for searches. It includes and overview page, provision for both the Mattson Method and Scenario Analysis for determining the Initial Probabilities of Area (POAs), a clue log, and will handle up to 20 search sectors and 12 search "waves" (typically operational periods, but I have deliberately not used that terminology, as I have been involved in searches where we used multiple search "waves" per operational period). The software revises the POAs down in proportion to the retrospective POD when no clues are found, and uses an assessment of the clues meaning and authenticity to adjust the POAs accordingly when clues are found. This version is version 2. I do have a version 3 in the pipeline with increased sector and search wave capability and an improved algorithm for handling clues. SARCalc is free to use for any search and rescue agency, or organisation training searchers and search planners. Copyright applies to the algorithms and code used in the worksheet, so should you wish to use part or all of the worksheet other than for directly planning a search, please contact me.

General Administrative Functions

The computer can be used for many of the general administrative functions of the field search HQ such as recording clue data, running sheets, radio logs, team status, etc.  I would recommend, however, that contingencies be in place to be able to swing into a manual system should the computer fail. This might mean needing the ability and discipline to print out a hardcopy of some data immediately after it is updated, or reasonably frequently, so that should the computer go down, important information isn't lost. The important thing here is to have enough information so that the success of the search and the safety of searchers is not compromised.

In general, I prefer to run manual systems for most general administrative functions. They work the same with or without power, and someone new coming in can usually pick up a manual system and run with it. Probability calculations are far simpler and quicker on the computer, however.

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