By Karl O. Steinke
I hike about 1000 miles a year, much of it solo. As you might expect, friends and family fret about something happening to me while I’m out alone. A friend brought me a SPOT sending unit along with an annual subscription to their service. The SPOT is sold as a “rescue” and/or “safety” device. The system includes a combination GPS receiver and satellite sending unit, and an e-mail send service. You put prerecorded messages into the mailbox along with an email list of people you want to notify. When you’re out, you can turn on the sending unit, acquire a GPS lock, hit a send key that broadcasts a signal to a satellite constellation which relays the message to the mailbox which broadcasts your location and prerecorded message to people on the mailing list.
The device has several modes, an OK mode that says I’m OK with time and location, a help mode that says I’m OK but need assistance, a 911 mode that notifies the local search and rescue organization that you need rescue, and a track mode that broadcasts your location periodically to people on your email list. You can have different messages and email addresses associated with the various modes. There is the cost of the sending unit (at the time about $200) and an annual subscription fee (at the time $150) for the service.
Sounds neat. I can keep a few of my friends aware of my whereabouts and I can call for a rescue if I or someone else is in serious trouble. The problem, I was only getting about a 50 percent success rate on top of a peak, clear skies, and hemispherical or near hemispherical coverage. I won’t rely on the flip of a coin if a rescue is needed. After about nine months and rereading the manual a couple of times and trying some timing variations on turn on and pushing buttons (at one point I had a suspicion that if the send button were pushed before a GPS lock was acquired that the send command was ignored). I decided to contact the SPOT help service. It was approaching time for me to decide whether to re-subscribe to the service or not.
I talked on the phone with a couple of people and had email exchanges with a couple of people with unsatisfactory results. They invariably ignored the symptoms of my problem. ”In a car… under tree cover… around buildings… during bad weather you may have poor coverage,” they said as they ran through their script. After I’d explain “clear skies, hemispherical coverage, mountain top, correct orientation” I got conflicting diagnoses.
“You didn’t leave it on long enough, it needs to acquire a GPS lock before you press the send button.”
“No, that’s not the way it works. You pressed the send key too long and put it into track mode. In track mode if the system doesn’t detect that it’s moving it doesn’t broadcast. We’ve had problems with that and redesigned the device to have separate buttons. Would you like to buy the new version?”
“That’s not how it works, sometimes in a car… under tree cover….”
I was suspicious that I might have a defective unit (cold solder joint or something):
“Can I get a replacement unit I think mine might be defective?”
“No. Sometimes in a car….”
“You obviously felt there was a defect in your old design. I’ve had unsatisfactory service. Can I get the redesigned unit and 6 months free trial service to see if you’ve fixed the problem?”
“No. Sometimes under tree cover…”
“Can I return my old unit and have you credit my friends account?”
“No. Sometimes near buildings…”
The SPOT is touted as an emergency device. The sole purpose of the device is to acquire a GPS lock and broadcast that information to a satellite for relay. There should be no combination of buttons you can push on the device (except on/off) that prevents that from happening. I suggested to SPOT they include an LED that indicates when there is a GPS lock (also not on my unit). If you can get a GPS lock, your chances of line of sight to other satellite constellations (and a successful transmission) is better. If you can’t get a GPS lock, move to a better location or wait for the weather to clear (if you can) so you don’t fruitlessly run down the battery.
Ideally you would have a sensor that detected a satellite carrier signal and broadcast when the system “knew” it was in line of sight. Don’t know if they now have an LED, don’t particularly care at this point. I no longer subscribe to their service since I consider the device (at least the one I had) to be a marginally reliable, poorly engineered novelty and their service substandard. Certainly not something I would depend on for rescue or want adding weight or taking up space in my pack.
I’m still getting pressure to have some kind of emergency back-up and am looking at a satellite phone (expensive - unit and subscription, but versatile) or a Personal Locator Beacon (emergency only) using the 406Mhz global satellite rescue system (e.g. the McMurdo products - at least some do include an LED GPS lock indicator) price runs $250-$500 but there is no subscription fee and you send back to the manufacturer after use for refurbishing (lightweight, cheap, notifies governmental rescue agencies). SPOT is a subsidiary of Globalstar. If I go with a sat phone that will weigh heavily when making my choice.
Karl O. Steinke is in System Security Engineering as part of the Program Protection Brigade Combat Team Modernization (BCTM) at The Boeing Company.