New Technology

Just ran into this in between shocks:
https://www.rei.com/blog/hike/recco-tech-in-hiking-clothes


Not in common use at the present, but perhaps in the future this will be commonplace

I wonder if it adds a lot to the price of the item? The SERE types will want to be sure to have some 'dark clothes' for when they don't want to be found!

A standalone RECCO backpack strap reflector is $38 on Amazon, and a backpack with integral RECCO reflector $79 (plus $20 shipping).

The REI article seems thorough, with good links, but here's RECCO at Wikipedia - one reference there says the helicopter RECCO sensor was demonstrated in mid-2015, with release then planned for Europe in 2016.

The strong suits of the RECCO reflector seems to be the passive nature and indefinite life, though I expect the 50 meter radius range pales compared to that of the 0.5 watt 121MHz active homing beacon embedded in PLBs. Of course, the RECCO was optimized to maximize the detection range through snow, not air.

The basic principle behind the RECCO reflector (harmonic reradiation from a nonlinear electronic circuit) has been used in countersurveillance "bug detectors" since at least the 1970s ( Nonlinear Junction Detector: Wikipedia), though I expect the RECCO reflector circuit is optimized to be maximally detectable.

Fascinating! I'll do a bit of reading on it.

Interesting tech.

Even watch straps available with it in.

https://www.strapstudio.com/product-category/recco/

Well, it's new in hiking clothing, but RECCO chips have been in ski clothing for quite some time. Most large ski areas now have handheld RECCO detectors, as do many SAR teams.

For some time teams have used hand held detectors from helicopters. This involves having an operator sit in the open door (tethered in of course), operating the unit. I think this was what was done on the 2018 Mendenhall Towers mission. More on that mission with a photo of the face is at American Alpine Club.

I think the RECCO detector on a helicopter long line is relatively new. Sounds like it has much better detection range. Until now the short range of existing handheld units has limited RECCO use for lost person (non avalanche) searches. This newer detector might make it more useful for wider area searches.

Rafowell posted a good link to the underlying technology. Basically anything with a diode in it can give a response (maybe weak) to a RECCO detector. Of course the RECCO chips in clothing are tuned to give the strongest possible response. I've heard of at least one avalanche recovery where the RECCO detected a buried snowmobile, presumably responding to components in the ignition system. The body of the victim was then found close by. When using hand held detectors the operator often has to remove any other electronic devices from their person, such as cell phones, watches, radios, etc. Having that kind of device in close proximity to the detector can sometimes give a spurious response.

I'm a bit surprised at the cost quoted for the RECCO devices to attach to helmets or packs. I think the chips themselves are quite cheap to produce. Then again, I suppose RECCO needs to make money to stay in business and pay for their development costs, such as the helicopter based system.

Yes, the current helicopter system is about 3 yrs old, vs. 36 years for the RECCO reflectors.

The RECCO map shows only 3 North American helibases equipped with this system (DPS, UT; Two Bear Air, MT; North Shore Rescue, BC.) vs. 8 for the Alps.

The RECCO history page says RECCO reflectors were first sold in 1983, the first helicopter-borne detector prototyped in 2014 (21 years later), and the current helicopter-borne detector introduced in 2016. It also shows considerable miniaturization of the handheld detectors over the years.


Their video cites a ground detection footprint with 50 m radius, not 100 m (I corrected my prior post), and suggests sweeping at a ground speed of 75 km/h ( 46 mph), producing a 100m wide swath. For wide area search, I wonder what track to track spacing would be recommended - I don't know how well helicopter navigation can control such spacing.

The RECCO detector for the helicopter is much larger than the handheld system - there are photos, videos, etc. on the RECCO site at the page on the RECCO helicopter system.

Forget helicopters. Can the current system be deployed an any existing drones? That could open up some real possibilities.

Hmmm ... my first answer was no, but now my answer is yes ...

The RECCO helicopter-borne detector weighs 170 pounds.(the foregoing is a nice article, btw).

Common, even semi-common heavy-lift drones top out at ~66 lb capacity.

But if you are willing to pony up about $250,000, then Griff Aviation's drones could handle it easily. The Griff Savior SAR drone is a candidate, though I think from the (scanty) specs that the Griff Rancher might be a better choice. Both are rated up to 441 lb payload, but the Griff Rancher includes GPS, and camera, unlike the Savior. Air time is listed as 30 minutes, but I expect that if one is not maxing out the payload, one can add batteries for more airtime.

Of course, this is a "cheap" solution only in comparison to a helicopter.

From the RECCO video clip, the RECCO unit is bulky - a rounded stubby cylinder about 2 ft diameter and 2 ft high.

The current RECCO helocopter-borne detector is smaller and lighter than the 300 lbs 2015 version.

Just fantasizing, but I could imagine a ground unit operating a drone over rugged or difficult terrain (think California chaparral) and covering a lot of ground quickly and efficiently.

Way better than what we did in days gone by

That's true, when I was a junior in high school, think around 1994, I bought a sky jacket that came with two RECCO chips, each inserted in a custom pocket built in the sleeves.
I don't think they added much to the cost of the jacket, both because my budget was pretty tight back then and because i remember purchasing it for other features, the RECCO system being just an afterthought.
When I showed up wearing that jacket at school, those RECCO reflectors became quite the center of curiosity and conversation among my classmates...

There's some technical and licensing information at FCCID.io, which appears to be a non-official compilation of wireless device applications filed with the FCC.

In the US, the device operates on a shared, secondary basis (on a frequency that happens to be within the 33 cm Amateur Radio band, around 902 MHz), with a maximum effective radiated power of 3.1 watts.

As a Part 90 device, it must tolerate (i.e., users can't complain about) interference from industrial, scientific, and medical devices. It is also forbidden to cause interference to the Federal Government Radiolocation Service, which is the primary user of the band.

In Europe, it operates at 867 MHz. The frequency was chosen to optimize effectiveness of reaching the reflector under snow.

Use is limited by the FCC to ski resorts and other areas of high potential for avalanches. Use is limited to actual emergencies involving threats to safety of life, and necessary training related to such operations.

So for various reasons, both technical and legal, this doesn't appear to be designed for general-purpose SAR use. It's really just for finding people in avalanches.

Excellent find and summary, Michael2 - thanks!