Being lost and walking just 4 kilometres creates a search area of 50 square

kilometres (20 square miles) which is huge. And in just 10 kilometres of

wayward travel the search area has expanded to 300 square kilometres. 

Confusion which is usually the source of the problem is no ally to the

situation. Becoming lost is at best stressful or at worst life threatening.

Victims find that cell phones usually dont work. Radios have limited range.

An investment into a 121.5 MHz EPIRB is expensive but worthwhile. 

An Aerotape advantage is that everyone in the group can have one,

because anyone in that group can get lost. 

The community responds to the information that people are lost by

committing massive resources of volunteer and profession emergency

workers, machines, helicopters and the like. All too often rescuers

themselves have to go into harms way. 

Testing has demonstrated that Aerotapes can be seen from a helicopter

at 3000 feet, one thousand metres, "as clear as day". This is a quantum

leap in visibilty. Aerotapes increase in visibility speeds up the process of

being found. Aerotape gives the S&R crews a viable target.

Time is crucial. Exposure and a possible expanding search area work against a

positive outcome. The rules about avoiding exposure and seeking shelter usually

go out the window because finding shelter means by definition you minimise your

visibility and your chance of being found. To be found you have to be seen. So

until now you couldnt seek shelter and be visible simultaneously.

With Aerotape lost parties can seek shelter, and deploy their Aerotapes in an

exposed position, such as a clearing or hilltop, to provide an enduring highly

visible emergency signal. Another Aerotape advantage.

Be seen, Be Found Lessons from field research Left click on photos on right to enlarge. Visibility and detection range testing was carried out both from helicopters and the ground. Various weather conditions were encountered from fine, to rain and overcast. Typical search altitudes used by the Police Air Wing were replicated down to 500 feet AGL (above ground level). In order to establish a baseline, initial tests were conducted to find a lost party in amongst the tree canopy from a helicopter. The level of difficulty in reliably detecting the lost party(s) due to canopy, shadows, branches and the bulk of trees at 500 feet AGL was such that the baseline tests became meaningless. Whilst results would have favoured the report, the only reasonable conclusion was that at this altitude it is exceptionally difficult to find people in amongst trees and results are near random. Testing the visibility of an Aerotape from a helicopter found that the tree canopy provided a contrasting surround in which the Aerotape presents as an exception. Lateral detection range was measured by GPS, and was reported at a kilometre and more. Testing was also conducted from a helicopter to assess the absolute altitude at which Aerotapes would be visible. When 3 aerotapes where placed in a cross pattern, hypothesised to intensify the visual signal, the crew had no difficulty in finding the target at 2000 on the first pass. The signal was "clear as day" at 3000 feet, a thousand metres. It was observed that best results were obtained when Aerotape was deployed horizontally in a clearing, in patterns, of multiple units. Tree canopy blocked out part the signal at a slant angles.  There was an obvious relationship between the number of Aerotapes deployed in a cluster and the ease of detection. Tests used between one and three units. Visibility testing ground to ground found that Aerotapes placed on hillside were readily visible through the canopy at 200 to 300 metres.

The conclusions are that a lost party in tree canopy is an elusive target and  from the air a person is found largely by repeated effort and luck. In contrast, from the air Aerotape provided a highly visible target, that can be systematically found. A further significant advantage is speed of search  where several square kilometres were successfully swept in minutes, whilst at a safe altitude. Aerotape outperformed all expectations.   Editors comment: When a one kilometre long, half mile landscape is compressed into these small pictures, detail is also compressed. Real world visibility is positively exciting.