Backcountry and side country exploration is becoming increasingly popular. In 2016, Yosemite National Park, for example, saw 25% more visitors than the previous record year, at 5M (1). Skiers have been flocking to Alpine Touring to get away from crowded resort slopes. Increased interest in the outdoors, however, brings increased risk exposure for those trying to get off grid. The ubiquity of cell phones and connectivity can give people a sense of security and backup that doesn’t hold in the backcountry. This, combined with increasing ease of access, can sometimes lead to trouble for underprepared explorers.  

Unfortunately, backcountry rescue can be tremendously costly, both in terms of time a victim often doesn’t have, and dollars required to marshal resources.

With WAASP, we aim to significantly decrease these costs for a large subset of rescue situations. WAASP is an airborne sensor platform for rapidly locating victims in a variety of backcountry scenarios. The last ten years have seen an explosion of activity in small-scale aerial vehicles, spurred on by decreasing electronics manufacturing cost and exponentially increasing density of compute power. At the same time, sensors have seen a similar shift, in some instances orders of magnitude cheaper and smaller than they once were. A $1200 consumer drone can fly a stabilized, cinema-quality camera with 20 minutes of flight time, when only a few years ago the only option was a manned helicopter with a gimbal system costing hundreds of thousands of dollars. WAASP takes advantage of these drone technologies and compact sensors to drastically reduce the time and dollar cost of victim location.

In short, WAASP aims to put mission-tailored aerial search capability in the hands of backcountry first responders for under $10,000, so that they might begin rapid wide-area search in the earliest stages of incident response, rather than waiting until the situation is dire.

  1. Yosemite stats: https://irma.nps.gov/Stats/SSRSReports/Park%20Specific%20Reports/Annual%20Park%20Recreation%20Visitation%20Graph%20(1904%20-%20Last%20Calendar%20Year)?Park=YOSE

Use Cases (Mission Profiles)

Avalanche Rescue

In-bounds and side-country avalanches represent a significant danger to large numbers of recreational skiers, and thus are a significant focus of mountain safety programs at ski resorts around the world. In general, in-bounds avalanches are very well controlled with modern operating protocols and mitigation efforts. For example: my home mountain (Mammoth Mountain) is at a relatively high elevation in the Eastern Sierra and sees an average of 400 inches of snow per year. It’s got a number of steep areas, prone to avalanche in commonly occurring conditions. Ski patrol has an extensive storm closure protocol to keep guests out of hazardous areas (on prone faces as well as in the areas slides can end up), and keeps a close eye on conditions to reopen this terrain after risk has passed. Besides these passive measures, they take active measures to trigger avalanches, or verify by failure to trigger that the snowpack is safe, both during and after storms. These include 105mm Howitzer artillery placements to bombard avalanche-prone faces, as well as a protocol for hand-placed RDX charges post-storm.

A well-prepared backcountry skier can take passive precautions, such as monitoring weather conditions and taking actual snowpack measurements (avalanche pit), to assess the risk of an avalanche during their activity. However, they can’t take the same kind of active triggering measures that resorts can. As well, active measures still aren’t fool-proof. The protocols above work 99% of the time, but there are still exceptional cases when a triggered slide is bigger than predicted, or changing conditions lead to unexpected slides after mitigation has already happened. For these instances, there’s a robust but time consuming on-mountain search and rescue protocol. In the backcountry, life-saving SAR can only be performed by other activity participants, who may or may not have themselves been involved as victims.

Rescue aids exist for such scenarios, but range in effectiveness. The most effective (fastest) solution is a system of avalanche beacons carried by backcountry riders. An enabled beacon sends out periodic radio pulses that can be directionally located by the beacons of other, non-victim riders.

A cheaper, passive system called RECCO is primarily marketed towards resorts: a powerful transceiver looks for a return signal reflected by small, cheap tags embedded in mid to high end clothing.

In the worst case, buried victims with no active locating measures must be found by avalanche probe – a tedious manual process of poking a 6’ pole into the snow until you hit something you think might be a buried victim.

In a resort scenario, or resort-adjacent sidecountry (where there are professional or trained responders nearby, but not necessarily on-scene at the time), WAASP could substantially reduce the time to locate first victim burial.

Consider a quadcopter vehicle outfitted with a lightweight avalanche transceiver implementation, a high-power RECCO transceiver, and a chalk dispenser. In the minute or two following an avalanche, patrol could fly this WAASP to the site of suspected burials, and rapidly begin remotely searching for beacon-equipped victims, while personnel were en-route to effect rescues. The WAASP operator rapidly locates any beacon-equipped victims, dropping chalk to mark suspected burial areas for personnel to get right to work on arrival. The drone can move much more quickly through the air than a rescuer on foot in the snow, saving potentially 5-10 minutes for the first victim location by pre-searching, and freeing up rescuer-minutes for secondary search and victim recovery rather than primary search.

Further, I find it plausible though outside of my expertise that one could fly a high-power cell site simulator, to locate buried phones at close range. By probing phones for a response, lightly buried phones could be located by a phased array receiver constructed from SDR components and flown on the WAASP. If such a system can legally be implemented, and if it is found to work through a few feet of snow, this could be used to rapidly find victims not equipped with more purpose-made RF locating technology.

In this instance, WAASP doesn’t eliminate the need for a highly involved and time consuming probe-line search, but could substantially reduce the time to find easier burials, allowing more time for rescuers to address more challenging ones.

Lost and Disabled Hikers

It’s fortunately rare, but every year backcountry hikers go missing, inured somehow without ready means to call for help. For example, mountaineers or high-altitude hikers experiencing unexpected altitude sickness, lost trekkers with dead batteries and no paper map, and canyoneers caught in flash floods. Often, the path to rescue for this type of victim is a resource-intensive SAR mission, often launched days after initial distress when someone fails to return to work on Monday, and frequently taking days or even weeks to complete.

In such situations, an authoritative agency equipped with a WAASP platform would be able to immediately begin a wide-area search for the reported victim, for only the capital cost of the platform and the operating cost of a ranger to fly it. For instance, the Yosemite National Park Rangers might be equipped with a fixed-wing WAASP with, say, 20 miles of range. This WAASP could be carrying a stabilized multi-lens camera module, GPS, lightweight thermal infrared imager, and an ISMI catcher with receive phased array, as proposed above. The operator could go to the rough area where the victim is expected, and fly 10 mile out-and-back sorties, using a wide-angle camera for primary search and having a closer look with a telephoto lens. Overlaid thermal video could further alert the operator(s) to possible victim location in the case that the victim is still alive. Finally, the ISMI catcher, if it locates a live cell phone, could very rapidly provide a more specific search region to operators. By recording all this data locally with concurrent GPS track, sensor data including video could be reviewed by other personnel with higher resolution and closer scrutiny, in case the initial pass missed crucial information in real-time.

In the case of lost hikers, WAASP may even completely preempt the need for a personnel-intensive ground search or expensive helicopter search, saving substantial money in addition to time.

System Architecture

WAASP is a modular ecosystem rather than a specific vehicle. One module might be the flight platform, for which there are many variants available. For instance, the avalanche mission profile above doesn’t require substantial range, but does require extremely low-speed or stationary loiter to precisely locate burials. This profile might be served well by a quad-rotor. The lost-hiker profile, on the other hand, requires substantial vehicle range to locate the victim over a broad area. In this case, a fixed wing vehicle with minimum drag and maximum range makes the most sense.

Sensors, too, must be swappable. While an avalanche beacon and radio telemetry for its data are critical for avalanche victim location, that sensor is almost certainly dead weight locating a hiker. Similarly, a thermal+optical camera may be the only sensor necessary to find a recently-lost hiker, expected back only hours ago.