Article from New Scientist  magazine, 17 July 2010, p. 20.

        Cheap drones could replace search-and-rescue helicopters

{and, one must add, could deliver munitions or CBW with little risk of interception or detection. 
Sorry about the name of the jnl in which the attached article was pubd   -  RM}

        The US military's uncrewed aerial vehicles are a critical component of its search-and-destroy missions in warring regions.  But could UAVs instead be used to save lives by flying search-and-rescue (SAR) missions in the nation's large national parks?
        Michael Goodrich, Lanny Lin and colleagues at Brigham Young University in Provo, Utah, took a commercially available propeller-driven plane with a 1.2 metre wingspan, optimised for low speed flight, and adapted it to both fly and search autonomously.  Their idea is to provide SAR teams with a cheap alternative to helicopters, and one that can be used even in the perilous weather conditions that can ground helicopter-led missions.
        Without any piloting experience, an SAR operator can direct the plane to an area they want to search by clicking way-points on a computerised map, Goodrich says.  The craft can also work autonomously to conduct search missions even if it is fed less specific information, such as a missing person's last known position.  To do so it uses computerised maps of the area to analyse the terrain and relies on probabalistic models to work out the
missing person's most likely routes.
        The mistakes most hikers make and the routes they take when lost are less random than you might think, says Goodrich.
Topographical and environmental factors play a big role in determining where someone ends up.  For example, once lost, people often stick to the easiest available ground rather than attemting to descend precipices or climb cliffs.
        Experienced SAR team leaders already read the landscape to determine in which areas to focus the search effort and in what order of priority, says Ron Zeeman, a seasoned member of Utah County Seach and Rescue.  Zeeman helped Goodrich's team determine the algorithms that allow their autonomous UAV to do the same.
        In trials, operators using the craft have taken between 35 and 150 minutes to find a dummy dumped in the wilderness - fast enough to impress Zimmerman.  "If we could use it right now, I would," he says.
        Although the system can predict where a dummy might be, the algorithms for detecting it within the images taken by the on-board camera still need work, says Goodrich. At the moment it's usually the operator that spots the dummy first.  With improved image-analysis software, the UAV could work entirely independently to locate missing people he says.
        The work will be presented at the AAAI Conference on Artificial Intelligence in Atlanta, Georgia, this week.
(Presumably that was mid-July.  The paper is attached.  RM)