Archive for the ‘Search Thoughts’ category

Changes to Re-Search

March 9th, 2010

I’m slowly getting back to a reality with internet access and computers to use. Apologies it has taken longer than expected…

Whilst I’ve been away, however, I’ve had time to re-evaluate my use of this website. Websites live and die through constant use; unless they are updated regularly they do not grow. This takes time and effort.

I have been happy to do this for this website for the past few months and it grew and hopefully people found it useful. However, the format of the website meant that any debates that were sparked were sometimes difficult to follow, and these were intermingled with useful “articles” or “features” and news items from different teams and copies of my own presentations.

So I have decided to migrate a lot of my “posts” to SAR World.

On here I hope to write daily news items, keep a directory of UK SAR organisations – from all SAR disciplines, add useful “features” and “articles”, maybe have equipment reviews and links to suppliers etc. All this will go on the “main” SAR world website, which in time will probably be funded by SAR equipment suppliers adverts. [In time any "profits" from this would go to a SAR World trust to be distributed to UK SAR groups!] I’m hopeful that this will be up and running sometime around April. [In time if all goes well this might extend to become a worldwide SAR resource!]

All the while everyone can join in the debates on the already existing SAR World Forum. Here I will post those thoughts likely to spark debate – as this is a much better format to discuss ideas and thoughts. For today’s thought/topic click here…

This website will remain up and running but will be limited to my presentations and links to SAR World debates / news / features.

Hopefully, in this way, I can improve on what has been started here.

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Another Re-Search Holiday

February 10th, 2010

It doesn’t seem like a month ago that I took two weeks off for Christmas and here I am taking another week and a bit off.

Unfortunately this is an enforced holiday from a technical point of view – a new kitchen means I’ve lost my “office” and computer for a while.

Never fear though… I will be back soon.

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Calculating Probability of Detection in Search and Rescue

February 9th, 2010

I wrote a couple of weeks ago about how to calculate a probability density distribution for a missing person search. This was the first element of the optimal search problem. The second element is to be able to calculate the probability of detection.

There have been numerous articles and methodologies proposed in the past. Most of these, unfortunately, have been wrong.

In order to calculate the probability of detection of a search resource you need several pieces of data.

Firstly the search resource’s track length must be calculated. In most cases this is simply a case of using a GPS track. However, with a foot search team, this must be multiplied by the number of searchers.

This figure is multiplied by the search resource’s “sweep width”. [I will explain more on sweep widths another time.]

This gives a Area Effectively Swept. This figure is divided by the Size of the Search Area to give the Search Coverage.

Once you know the Coverage you can use Koopman’s Exponential Detection Function to calculate POD.

Simple, eh?

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More thoughts on ALSAR

February 8th, 2010

It might have seemed over the past few weeks or months that I am somehow “down” on ALSAR. This couldn’t be further from the truth.

So today I wanted to write some brief thoughts on what ALSAR does do well.

First and foremost, it has to be said – without ALSAR the UK would not have the excellent lowland (or vulnerable missing person) search capacity that it does. ALSAR saves lives…

It does this by supporting local county teams, helping them set-up, giving them the professional backing that means the police trust and use them. Never, ever underestimate the value of this!

ALSAR also does an excellent job in building a “community” within lowland SAR. Wherever I go I am always at home within any ALSAR team. Not only that but the strengthening ties between ALSAR and MR means I am welcomed into and feel welcomed by MR members I meet.

ALSAR also does an excellent job at representing us all at a National level! Adrian Edwards represents us all in a very professional manner, allowing us all to reap the rewards of his committee ability!

I’m sure everyone here can add loads too…

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Mountain Rescue Campaign to Save VAT

February 5th, 2010

The Mountain Rescue England & Wales campaign to get HM Government to waive VAT for MR and ALSAR teams got the backing this week of Private Eye.

As they comment;

Gordon Brown waived VAT at a stroke for the Simon Cowell produced celebrity cover version of Everybody Hurts to raise funds for Haiti. The mountain rescuers don’t begrudge the earthquake victims a penny; but they wonder why the government can’t do the same for them.

Maybe it’s time for us all to start contacting the prospective candidates for our constituencies getting their support for after the election?

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