Friday, December 21, 2012

The View From Above

While the end of the world is likely not coming, the snow is!! For those of you who love to go out and play, camp, hike, or ski in the white stuff, here is a great write-up by BAMRU's Alex Grishaver on how to help get spotted should you loose your direction crossing snowy terrain:

Ever wonder what a helicopter pilot sees while flying over a wintry wilderness area? On a recent Tahoe search, we got some compelling visual evidence of what's easy and difficult to see from the air --  with important lessons for all you outdoorsy folk.

These shots were taken from the air by a local deputy in the South Lake Tahoe area (specifically, near Upper Velmer Lake), where we had, thankfully, just made contact with a lone hiker who'd been pinned down in the first storm of the season. The helicopter was probably between 200-300' above the ground. What do you see in this first photo?




Well, hopefully you see… trees and snow, of course. A stream. Some very high-contrast shadows. And tracks! You may spot some people (or you may start to infer where they are based on the location of tracks). But you have to admit, people are pretty difficult to make out here. Even in when a helicopter is hovering in a stationary position, there's plenty to distract: vibrations; glare; reflections; etc.

Here’s another photo taken a minute later:




In this last photo, you might be able to make out one individual.




In fact, there are 7 other rescuers behind a cluster of trees, chatting with the hiker -- who was in fine condition, but who had been tent-bound for 5 days and was facing, at best, a 10-mile slog through 4-foot snow drifts in trail-runners if we hadn't found him. In this particular search, crews on the ground made contact with the hiker, who saw the helicopter drop them on a ridge and then used a whistle to alert us. The helicopter crew didn't actually see the hiker until after we'd made contact.

Yes, the photos aren't of the highest resolution. But the deputy who snapped these shots attested to the great difficulty of seeing us, only a few hundred feet below him. And the helicopter crew has way more visual information to process than what’s captured within the small “window” of these photos.

It's hard to see people from the air.  However, tracks stand out well on fresh snow, and stomping a message or pattern is surprisingly effective, quick and easy.  If possible, you should still try to attract attention with bright, geometric patterns in a clearing.  High-contrast patterns also work in other environments: spreading lightly colored gear against a dark background (or vice versa) can assist you in getting attention when you need it.

Have fun, and stay safe!


Written by Alex Grishaver, Edited by Matt Jacobs, Photo Credit: Deputy D. Frisby, CHP