One wonders with all the "searches" going on for Kyron Horman at Sauvie Island even if they are just a training exercise (see: Sauvie Island searches: A training exercise. Is Terri no longer a suspect? ) why they are not using balloon cameras, mast cameras, blimps (camera as well as passenger), and cluster / weather balloons as a search aid. This type of technology is beneficial for searching some areas especially open fields and over blackberries.
Blimps can be camera sized or 1-2 people sized (or larger) They are often used for surveillance and are often camera equipped. There is a blimp manufacturer in Eugene, Oregon (link below) that could be of assistance with coordinating a blimp search.
Blimps can hover in one place and are maneuverable. They can stay aloft for a long time and should be used more over in search and rescue operations.
Cluster balloons are weather balloons tied together to either lift a human or camera equipment. A tethered weather balloon can be inexpensively used to carry a camera or grouped together to carry a person with a camera.
You can buy a weather balloon starting at $6..00 (plus the helium) In fact, there are amateurs who send camera equipped weather balloons into space to take pictures - some of them rivaling satellite images (see: Father and son film outer space, do-it-yourself style ) Tethered, they make an economical surveillance system for search and rescues.
If they are serious in their search for Kyron Horman on Sauvie Island - which I doubt they are - they would use everything possible to search including aerial camera equipment. This weekend looks like even more of a training exercise and to keep the interest up about Kyron because they are accepting just about any volunteer that wants to help search.
The county’s search and rescue crew will be there along with other agencies and nonprofits groups that have supplied volunteers, said Lt. Mary Lindstrand, spokeswoman for the sheriff’s office
Blimp camera: http://www.raidentech.com/rarecorcblrc.html
Passenger blimp manufacturing: http://www.ahausa.com/ (Eugene Oregon)
Mast cameras: http://www.aerialproducts.com/aerial-photography-systems/mast-pole-camera-systems.html
Weather balloons: http://www.scientificsales.com/Meteorological-Balloons-Weather-Balloons-Sounding-Balloon-s/25.htm