Paging Jonathan..... Go-Pro camera interfering with beacon search?

[Bunion 2020]

A friend was over at Cooke City with a buddy of his. To sharpen the buddies beacon skills my friend set up a simple single beacon drill and the buddy attempted to locate the buried beacon while using a running Go-Pro camera to record the search and his time.

While the HD camera was running he got strange distance readings and conflicting arrow directions. When he turned off the Go-Pro things cleared right up.

Any thoughts?

[bushman]

Awaiting beta, it matters.

[camlax]

no idea off the top of my head but i'll test this in the beacon park with a few different beacons tomorrow. looking forward to hearing other opinions though

[Hacksaw]

Randy,
What transceiver was he using? And what transmitting transceiver was he searching for? I have no experience or a GOPRO camera on hand to test this.
HM

[Jacolac]

I wouldn't be surprised at all. I use my Gopro for another hobby of mine which uses wireless video transmission and having the Gopro on nearby significantly reduces the video range and quality. It's known to be quite "dirty" when it comes to electromagnetic interference that it emits.

However, it has only been a problem for me when it’s within about a foot or so of my video transmitter so when it comes to beacons, it might be safe to wear on your head but a chesty mount is probably a bad idea. Although beacons may be much more sensitive to this kind of interference. I’ll try to do some tests with my beacon this weekend.

[Piggity]

Maybe a follow up question after this one about gopro is answered, does it also happen with a Contour or other video cams?

[Jonathan S.]

A friend was over at Cooke City with a buddy of his. To sharpen the buddies beacon skills my friend set up a simple single beacon drill and the buddy attempted to locate the buried beacon while using a running Go-Pro camera to record the search and his time.

While the HD camera was running he got strange distance readings and conflicting arrow directions. When he turned off the Go-Pro things cleared right up.

Any thoughts?

I think you've pretty much already conducted a very well-controlled test.

In general, comprehensive beacon testing ends up becoming a never-ending cycle of repetitive mind-numbing tedium, as it's always possible to coming with new testing configurations to highlight various quirks, and then new firmware versions are always coming out, and results are seldom reproducible 100% of the time which means repeated trials and trying to discern patterns, etc.

By contrast, testing interference with specific combinations of beacons and other electronics devices is pretty straightforward, and you've already done it for this particular combo. I wouldn't be at all surprised though if you find different results with a different beacon and/or different video camera. Plus even in cases of bad interference, just relaxing the proximity a bit would probably help enormously ... although with a helmet-mounted camera, well, the natural reaction to encountering strange readings might be bring your head and beacon even closer to each other thereby exacerbating the situation.

I'm also very grateful to you for bringing this to our attention. In the avy courses I teach, I always stress the importance of maintaining a big distance between a beacon and any smart phone or MP3 player (or preferably keeping them off in the first place). I'd never even though about a POV video camera though, just b/c I don't know anyone who has one. (Pretty amazing, huh?) But the potential to mess up a beacon search, and furthermore be unaware of the cause, is very scary!

[sierraskier]

I was recently told by an ACMG guide they see this happening with the chesty-mounted newer Hero models and the Mammut digital transceivers specifically.

[homemadesalsa]

We saw a lot of anecdotal problems with the iPhone and an older version of the Pieps DSP. Jonathan hits it right on, though. Any electronic device puts out a field that interferes with a beacon- keep them separate and off.

Although I can see, in the future, a mixed-use device that is really just a phone (which is a computer) that transmits and receives, using GPS capabilities.

[nickinbc]

Although I can see, in the future, a mixed-use device that is really just a phone (which is a computer) that transmits and receives, using GPS capabilities.

I think that is a really bad idea:-

Now which menu and do I go to to turn to search?

Shit, it fell out of the pocket I put it in after that last call.

Damn, the batteries have died because I was using it to phone/take photos/play music.


Keeping essential safety equipment simple is a good idea IMHO. Combining it with a toy (sorry, essential social networking device) is not.

[coreshot-tourettes]

If someone has a GoPro in the Front Range area, I have access to a $2M electromagnetic compliance chamber that we could throw it in and do a quick 2-axis scan to see what bands a GoPro spikes in. PM me.

[PNWbrit]

that transmits and receives, using GPS capabilities.

Through snow?

Not going to work.

[Dickeymotto]

If someone has a GoPro in the Front Range area, I have access to a $2M electromagnetic compliance chamber that we could throw it in and do a quick 2-axis scan to see what bands a GoPro spikes in. PM me.

That is pretty rad.

[time2clmb]

FWIW I just did a search with a tracker 1 and 2 both ways vs. Gopro and only noticed 1 small spike of .1 difference 1 time when I had the tracker 2 touching the Gopro but could not repeat it. I tried with the Gopro a couple feet away and then again right next to the transmitting beacon. Totally non scientific and I claim nothing...take it for what it's worth. Using the last gen Gopro HD...not the newest one.

[Bunion 2020]

O.K. some updates now that I have had a chance to talk with the guy involved.

The Search Beacon was a Barryvox Pulse 2 yrs old.

The Go-Pro was the newest model, has the LCD screen on the back.

Symptoms: When searching for the buried beacon (target) a 3-4 yr old Arva there was no signal until the searcher got within about 15 meters of the target. At that point the search beacon would register the target but the distance would vary between 15meters, then 22 meters and then no signal.

Puzzle over that.

[McCorduroy]

FWIW, the instructors for my avalanche L1 course this weekend advised that any device with a microphone (e.g., an iPhone or POV camera) should be kept a minimum of 30cm from your beacon.

[grskier]

O.K. some updates now that I have had a chance to talk with the guy involved.

The Search Beacon was a Barryvox Pulse 2 yrs old.

The Go-Pro was the newest model, has the LCD screen on the back.

Symptoms: When searching for the buried beacon (target) a 3-4 yr old Arva there was no signal until the searcher got within about 15 meters of the target. At that point the search beacon would register the target but the distance would vary between 15meters, then 22 meters and then no signal.

Puzzle over that.

Interference is interference... that's sort of how it works. no sort of consistency.

[NatEE]

FWIW, the instructors for my avalanche L1 course this weekend advised that any device with a microphone (e.g., an iPhone or POV camera) should be kept a minimum of 30cm from your beacon.

Probably a good rule of thumb. I doubt this is actually limited to devices with microphones though... It's likely that switching power converters are the culprit in generating the interference, both because of the frequency involved, and the fact that those circuits have a tendency to be noisy. So anything with one of those circuits in it has a possibility to generate interference. This would include almost all digital devices. Even headlamps commonly use "pulse width modulation" for dimming (where the LED gets shut on and off quickly, generating a kind of strobe-light effect), and it wouldn't surprise me if one of those was enough to throw off a beacon.

[SDW]

Dammit my beacon won't work near the microwave either. POS! I'll post it for sale in Gear Swap for anyone interested. I'm switching to an airbag pack now.

[homebrewd]

O.K. some updates now that I have had a chance to talk with the guy involved.

The Search Beacon was a Barryvox Pulse 2 yrs old.

The Go-Pro was the newest model, has the LCD screen on the back.

Symptoms: When searching for the buried beacon (target) a 3-4 yr old Arva there was no signal until the searcher got within about 15 meters of the target. At that point the search beacon would register the target but the distance would vary between 15meters, then 22 meters and then no signal.

Puzzle over that.

Or perhaps you found your wavelength on the signal? I'm assuming as these beacons are low frequency they will have a longer wavelength

[coldfeet]

Probably a good rule of thumb. I doubt this is actually limited to devices with microphones though... It's likely that switching power converters are the culprit in generating the interference, both because of the frequency involved, and the fact that those circuits have a tendency to be noisy. So anything with one of those circuits in it has a possibility to generate interference. This would include almost all digital devices. Even headlamps commonly use "pulse width modulation" for dimming (where the LED gets shut on and off quickly, generating a kind of strobe-light effect), and it wouldn't surprise me if one of those was enough to throw off a beacon.

I know F-all about beacons, well, but a little about electronics. I have an analog beacon (F1). Since it's analog, it should pick up interference as an audible signal, and it does. By playing around with it in my house, I can verify that various electronic devices cause static on it. Most of the time this is a low background hiss, but if you get something close to the beacon, it can be quite loud. The AC power brick for my laptop causes a large amount of interference (more than the laptop itself), which confirms what you suggest. Switching power supplies are known to cause a lot of RF noise. My cellphone causes a little noise but if I do something to wake it up and ping the tower, there is a noise spike. An LED headlamp wasn't too bad. A camera caused a little noise, I didn't try running it in video mode. Interference is unpredictable, so two different camera models could easily differ by a lot.

This is analog so I just hear static hiss. I wouldn't be surprised if strong static caused digital signal processing to behave oddly.

Interference falls off fairly rapidly with distance from the device. I suspect that the offending Gopro was on a chest mount rather than head?

Bottom line is sort of common sense: I don't think you want an active electronic doodad (Gopro, ipod, cellphone, ...) close to the RECEIVING beacon.

[Pinner]

If someone has a GoPro in the Front Range area, I have access to a $2M electromagnetic compliance chamber that we could throw it in and do a quick 2-axis scan to see what bands a GoPro spikes in. PM me.

Did this ever happen?

[TBS]

Coldfeet's comments above mesh really well with this report from Beacon Reviews http://beaconreviews.com/transceivers/Interference.asp

Upshot - any device that emits an electromagnetic field (i.e. anything that requires an electrical current) can potentially interfere with a beacon's reception. Distance between devices seems to matter a lot.

I've done practice searches with/without my iPhone playing music and have only had a problem once - which was enough to spook me. Better to keep them off when traveling in avy terrain - you can always turn them on for GPS, recording observations, doing a naked snow dance to Ullr or whatever.

[SchralphMacchio]

Thanks so much for posting this. Another great reminder to enforce with our touring partners to keep their electronics off and/or well away from your chest while touring.

It's too easy to say "yeah, well it's only a problem while I'm searching, so I can have this iPod or GPS or SPOT in tracking mode banging away for now and keep it in my convenient chest pocket and turn it off later," when in reality, you won't remember to turn it off later, and that is going to be the last thing on your mind if your friend is somewhere down below and all you see is a big debris field.

[komo]

BUMP

for truth, relevance, thread police