Monday, April 13, 2009

PLB Review

Personal Locator Beacon (PLB)

My longest post yet and not even getting one, sigh... If I was going to be in some remote region I would probably give this more consideration but no matter what I do I just can’t justify the cost and will not be bringing one along.

Thought I would do a post on it anyway because I find them very interesting, also found some very misleading information on new lower cost options which market the same functionality but aren’t the same thing at all.

406MHz PLB will run between $500-1,000+ and they serve one purpose, press the button and someone is going to come get you. There are some lower cost products around $150 that call themselves a “PLB” (and I guess they are, using a loose definition) but they don’t transmit on 406MHz which is extremely important, you will see why in a minute, wouldn’t bet my life on them just to save a few bucks. SPOT tracking device is one of those products and what sounds really cool when you initially read it, has some major drawbacks and hidden costs, I'm not a huge fan of subscription based services.

Will highlight the differences from my perspective and why they may be important, might be a little long winded and boring but oh well, it's my blog.

First, how a real 406MHz PLB works

When you buy your unit you register it with search and rescue services (no cost) and provide full contact information, each device also has a unique number associated to it and YOU. When you activate your PLB in life threatening situation it transmits two signals one on 406MHz @5W, powerful enough to reach satellites through stormy weather or heavy tree-cover and another on 121.5MHz at much lower power which is actually a homing beacon. If the PLB is also GPS enabled, which I highly recommend, then the signal includes Lon/Lat co-ordinates as well as your Unit Id.

Now what?

There are a series satellites called the COSPAS – SARSAT system, COSPAS is an acronym for the Russian words "Cosmicheskaya Sistyema Poiska Avariynich Sudov," which means "Space System for the Search of Vessels in Distress, "SARSAT is an acronym for Search and Rescue Satellite-Aided Tracking. You may have guessed from the terms, whole purpose of these satellites are to monitor distress signals on 406MHz, same ones used by commercial marine vessels and aircraft so proven technology.

COSPAS-SARTSAT system is made up of two different satellite systems, Low Earth Orbit Search and Rescue Satellites (LEOSAR) and GeoStationary Search and Rescue Satellites (GEOSAR) both are designed assist in detecting and locating activated satellite beacons, there are some differences in how this works depending on whether you have GPS enabled device or not.

There are 6 LEOSAR satellites which orbit the earth, when a satellite detects a distress signal it uses Doppler Rader to get fix on your position which is accurate a 5 mile radius. Because they are orbiting the Earth there can be dead spots as it takes something like 2 hours for a full orbit, when the signal is first detected the emergency distress is sent to ground receiving station called a (LUN) they then try to fix the location but may need to wait for the next satellite to come into view before they can get a position so there may be a delay unless you have GPS enabled device. .

There are 24 GEOSAR satellites in fixed position around the Earth which provides 24x7 coverage for the entire earth except the poles themselves, when a satellite receives the distress, forwards instantly to the LUN, if no GPS on the unit then the LUN still has to wait for the LEOSAR to get a Doppler fix but at least they get notified quicker and can start organizing the rescue. If you do have GPS enabled unit then the GEOSAR satellites will send this information right off the bat which means response time is that much quicker. Make sure your unit has GPS.

Ground Station then forwards to a mission control station tries to verify the emergency by contacting you and then will co-ordinates rescue efforts. With GPS info the rescue team can get within 100 meters of your location, without GPS this is where the 121.5MHz homing beacon comes into play, rescue team goes to the 5 mile radius provided by the LEOSAR system and then they monitor the 121.5MHZ frequency to home in on more exact location, still can only get to about a football field range but that’s pretty close especially if you're the one in the water yelling pick me, pick me.

Note: Older PLB’s only transmitted on 121.5MHz but the satellite system no longer monitors it as of Feb 1, 2009, they still use the 121.5MHz for ground monitoring and homing in but that too is being phased out, make sure your unit is 406MHz capable.

There are many versions of these, some are waterproof, some activate when they hit water or other impacts, some have strobes etc, ALL of these 406MHz PLB’s use the COSPAS-SARSAT system.

Now the SPOT (and others like it) in my humble opinion as a life saving device is has some flaws and more marketing hype than anything else, decide for yourself but based on what the above does, would you trust your life to this method? Better than nothing I suppose.

Device itself costs $150 dollars, read between the lines, requires additional subscription of $100 a year and if you want unlimited tracking then another $50 a year on top of that. Includes the following services:

911 Locator

You register your product online and like the 406MHz PLB’s they have a unique number and are GPS enabled. They use a private satellite system that is monitored by the company itself (Atlanta) who then forward the distress to appropriate authorities who you have to setup before hand. The unit takes up to 20 minutes to send and has less coverage area, that could be the difference between life and death. They don’t transmit on 406MHz so you have to go through a 3rd party and need to subscribe to their service, may work once without subscription I think but then cost of additional suport is quite significant.

Ok Feature

Sends pre-configured emails so when you press the button it sends the email to the people you assigned it to, kind of neat but seems to be only available if you have the subscription package.

Help Me Feature

Sends a pre-configured email to personal contact that you need help from, and they know where you are how? Hope it includes GPS info. Seems to be available only with the subscription package

Tracking Feature

Allows you to track GPS waypoints online and need to reset every 24 hours unless you subscribe to unlimited tracking. Don't know many people with ready access to Internet while on extended trips, need the subscription to take advantage of this.

To activate the SPOT you press the 911 button, which is recessed into the
unit, I can see accidentally hitting that one a few times, don’t have one to try it. With most 406MHz units they have a protected switch cover that you have to open to activate which should prevent this.

These types of units I view more as a neat gadget and when you factor in the subscription costs I personally wouldn’t waste the money, would spend a little more and get something that is monitored by rescue people themselves.

SPOT System has rescued 4 people since 2007 (according to one site) 406MHz has done 74 just for PLB devices alone since last year, 24,000+ rescues worldwide since 1982.

Search and Rescue Satelite Website

No matter what choice you make, common sense prevails. Distress signals should only be used in situations of grave and imminent danger, and only as a last resort when all means of self-rescue have been exhausted. There are huge fines and possible jail time coming your way from deliberately misusing one and wasting time of rescue people who could be saving people in actual danger.

If you accidently activate one you need to cancel it and call the Rescue Service to let them know it was a false distress, otherwise they are sending people out and it could get a little sticky if you're sitting on the dock enjoying a beer on a sunny day when the helicopter shows up.

Article I read somewhere pretty much says it all.

“To truly accept the idea of a personal locator beacon (PLB), you have to accept the idea that every spot on the Earth can now be seen by the network of satellites in orbit. There is no longer any place that is truly wild, unexplored, or free from the reach of technology, which flies in the face of the concept of adventure and self-reliance. But the upside is that when you find yourself staring down death somewhere in the back of beyond, a satellite beacon the size of a flashlight may well call in the cavalry”

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