Wednesday, April 11, 2012

Spot Checked and Rechecked

Back in 2008/2009, when the Spot Satellite Personal Tracker was relatively new on the market, a number of authors reviewed the device and service. Opinions were not particularly good, and deservedly so. The user interface of the device was kept intentionally very simple, to the point of making it difficult to use without either developing an intimate familiarity or a check list. The reliability of the data link was not particularly good especially under circumstances that outdoor enthusiasts would consider common when a device such as the Spot may be most desperately needed. One article, first published in Kitplanes Magazine (subscription required) and later republished in SARSCENE Magazine, even compared the Spot to two alternative technologies: 406 MHz PLB/EPIRB/ELT, and satellite telephone. If you looked at this kind of technology at the time, what ever your decision, there are two important reasons to have another look. First, the technology is always improving and there are new and affordable products on the market; second, the basis of comparison of the three technologies in the Kitplanes article was incomplete.

New Products or Services

Spot

Spot LLC must have listened to some of the criticism because they have released hardware with an updated user interface and potentially better performance. 

406 MHz PLB/EPIRB/ELT

406Link from ACR Cobham now allows owners of at least some 406 MHz beacons to test the functioning of their equipment. With the basic service you can "test your beacon multiple times through the Cospas-Sarsat satellite system! You'll get peace of mind knowing your beacon is working properly with self test confirmation messages sent to your cell phone and email." With the plus service you get all the capabilities of the basic service plus "the added features of multiple SMS and email messaging (up to 5 contacts), trip planning and GPS test location..." Newer GPS enabled PLBs will also allow you to hyperlink a map of your GPS location.

This is a very interesting service, and has some of the same features offered by the Spot. However it makes use of the self test message protocol of the Cospas-Sarsat system so can not really be considered a full competitor to the service offered by Spot. It will however let you know that your PLB is working by closing the loop. More importantly it will let you find out if you will be able to summon help from you favourite camp spot or stretch of white water; or if you may have to somehow get to higher ground in the event of an emergency.

Satellite Phone

Iridium has partnered with Twitter to provide micro-bloging support to their satellite phone users. While not specifically an emergency notification service, a satellite phone can be used to call for help. If you have been keeping your friends and family up to date with your progress along the way even a poor quality, prematurely terminated phone call can get help moving your way more quickly. Your actual location where you need assistance is, of course, the most important information you need to communicate. But often knowing your planned route and where things were last OK is all rescue teams need to get to you.

Iridium Based Trackers

The Track24 Packetmaster series provides world wide position tracking and emergency alerting through the Iridium satellite system, as do the Nal Nano Shout and the inReach, each in their own way. There are probably others.

Recommendations?

I'm not going to make any. I don't have access to all of these systems, and if I did my test conditions and usage probably would not be close enough to yours for a proper comparison. When choosing emergency equipment there is no substitute for doing your own proper research. Talk to people who are active in the same areas and pursuits you are. Read reviews in magazines and trade publications. But always be sceptical, especially of recommendations or comparisons.

Dubious Comparisons

Which brings me to my second reason. In his article SPOT, Checked Dr Langley Muir did a reasonable job of informing his readers on the benefits and failings of the Spot Satellite Personal Tracker. He then went on to offer as options two of the other technologies I have also discussed: 406 MHz emergency beacons and satellite phone. Also well and good. But, he goes so far as to compare the technologies on the basis of frequency and power stating "The five-watt signal ensures that messages will get out unless you are in an extremely bad position. If you push the button, a full SAR effort begins;..." What is an extremely bad position? I suppose if one were to define an extremely bad position as one where a 406 MHz beacon is not able to get a signal out to Cospas-Sarsat, then Dr Muir's assertion is accurate enough. But then it is also a meaningless tautology. Power is not the only, nor necessarily the most important factor in determining radio link reliability, especially when comparing different services.

If I may digress for a moment to make a point. The Bugatti Veyron has an engine rated at 987 break horse power and boasts a top speed in excess of 400 km/h. The Oasis of the Seas has six engines totalling 130,110 horse power but can only manage 41.9 km/h. Clearly horse power is not the only factor in determining the speed of a transportation system. I am neither an automotive engineer, nor a naval architect but I know that there are many factors that come into play when determining top speed, some of which I have probably never considered or heard of.

Radio communications link reliability is similarly subject to many factors. If you are interested, and up to the mathematics there is a very good tutorial published by Charan Langton of Loral Space Systems. If I have any recommendation I would say be dubious of anyone who offers over simplistic comparisons. I will make one suggestion, watch the CBC Documentary The Trouble with Experts before acting on any recommendations; especially if your life may depend on your decision.

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