An Underground Radio to Save Lives

Roland Piquepaille writes "The Duluth News Tribune wrote last week about a communication device which could be a lifesaver for miners. This invention is the brainchild of David Reagor, a physicist at Los Alamos National Laboratory (LANL). His prototype radio works at depths of 500 feet and is based on very low frequency electromagnetic radiation and digital signal processors. A commercial version is in the works and could be used not only by workers trapped in a mine, but also by firefighters and other emergency workers to communicate with people in collapsed buildings or subways."

Comments

VLF has been used for submarines for decades

[ishmalius]

Very low frequency (VLF) has an extremely low data rate, yet it has a great ability to penetrate earth and water. The Navy has been using it for a long time to communicate with submarines.

Re:VLF has been used for submarines for decades

[skogs]

It seems you do not understand VLF/ELF ideas. The entire point is that it is a super low frequency. Low frequency doesn't cycle very often, and makes it hard to press data...so it would be rather difficult to compress audio and then send it.

The navy's ELF is just that...ELF...it sends text only. This is no email system, this is exactly what needs to be sent, and thats it...and some messages take several minutes to send. Sending voice data would take an extremely long time...and transmitting for that long wears down batteries. Your LMR(land mobile radio) be it motorola, etc, MIGHT last an entire day or 8/12 hr workday...but it only gets keyed for about 20 minutes of that timeperiod, if that.

I think, even if it was VLF instead of ELF, they would be far better served to make a keypad, and force people to type short messages to transmit. That way it might actually last for 3 or 4 days if there were an emergency. Otherwise it simply wouldn't have the power to maintain sporadic communications for that kind of timeframe.

Troglographs are not new

[TechyImmigrant]

Troglographs are not new.

Nothing new here

[n1ywb]

As usual, there is nothing new under the sun. Cave radios have been under active development for some time. Check out these resources

Cave Radio & Electronics Group
Google "Cave Radios"

Granted this guy's sounds a little more advanced with DSP and stuff, but still not a new concept.

partially a matter of economics

[fermion]

The talk lately has been that plenty of technology exists to help in rescue efforts and insure the trapper persons survive until rescue happens. The probelm seems to be funding for production, the market for these devices is very small, following existing safety regulation, and training. THE VLF frequency radio is nothing new, and this just seems like a way promote the technology and encourage the federal authorities to mandate the device, and probably use tax monies to partially fund the deployment. I don't know why we would want to do this insted of enforcing the current regulation, perhaps raise fines on violation, and, if we want to be realy radical, actually expect the fines to be paid. In fact USA Today, which I am lothe to quote, seems to think that the current rash of accidents are a result of lack of enforcement over the past several years, and not the direct result of the lack of any safety equipment. I know that I would much rather be at the dinner table with my family than trapped in a mine, even if I did have the ability to say goodbye with my last dying breath, and with the full knowledge that the mine company will get the digging equipment in as soon as humanly possible, and would pay the $5000 fine for the accident, if it survived the appeal.

Which is not to say that accidents never happen, but when a mine has been cited at nearly every safety inspection, and has not paid fines, one wonders whether more safety gizmos are really going to do any good.

Not deep enough

[ajdlinux]

Here in Australia there are two miners trapped around 935 metres (3116 ft) below the ground. They managed to contact them using existing radios. Fact is, most mines are deeper than 500ft.

Developped in caving activities up to 1Km deep

[zijus]

Hi there.

You better check that out : systeme Nicola. I don't put a hand on publishing date, but some folks in Europe are developing such a system for a while. They are aiming at caving rescue activities. In specific conditions they got the communication through 1000 m of rock. Interesting. Funny as well to get a feeling on how polluted can be our environment in the low frequencies realm.

Bye. Z.

Three cave radios

[Anonymous Coward]

I'm aware of these three underground radios:

- The MolePhone
- The HeyPhone
- System Nicola

I believe they all operate at around 87 kHz. The Mole Phone has been around for 30 years or so; the others are newer and more high-tech, with greater range.

Re:Lifesaver for commuters, too

[AB3A]

Uhh, radios DO work in the "underground." The Metro in Washington DC does this, as do many other subway systems. The technology has been around since at least the late 1970s. It's really quite simple: A leaky coaxial cable (Andrew Corporation makes one called Radiax) can be used for both receiving and transmission. If what you say is accurate, the folks managing the London Underground could really use an education.

Now as for mines, such systems are useful for tunnels which don't change much, such as underground railway tunnels. Engineering these systems on an ad-hoc basis isn't simple, nor cheap. Mines need to use something better. A robust digital modulation scheme which can survive multiple repeating nodes with less than ideal signal to noise ratios is something which needs development. Ideally this system would use something robust like turbo-codes, where a damaged packet could be recovered with some delay.

This could result in some messages taking many seconds to get to and from the surface, but at least they'd get there...