Long post...
Last night I had an interesting chat with two industry experts. One being the head of a Southern California Search and Rescue team and a Coast Guard small boat rescue captain. They brought some stuff to my attention...
Iridium/Inreach/Garmin: While it appears to be very similar to the SPOT setup, the Iridium network and satellite constellations are backed by and heavily used by the United States gov (bailed out by the gov a few years back). The network is more advanced, more saturated with little things in the sky.
Global Star/Spot: Both of the guys I talked to thought that STOP and Global Star will never be able to keep up with the conglomeration of Iridium/Inreach/Garmin. The Global Star network has had issues in the past with satellites going down, and the company was slow to respond.
Both of these companies use low-orbit satellites, which have faster orbits than the rotation of the earth itself. This is a plus and a minus, plus being that they wiz around pretty damn fast, and your chances of getting a ping to the emergency center can be increased. Sadly, if you are stuck in a canyon somewhere, the limited amount of time that the satellites are overhead won’t allow the entire signal to get out. The basic SOS will get out, with the ID number of your device, but that’s about it.
I knew all this stuff for the most part, but what I didn’t know was with services like Garmin and SPOT, if you smack that SOS button and only your SOS signal and device ID go out, the emergency center will get that information and can start making calls to try and pinpoint where you are. If your device is not able to get out GPS coordinates to the satellite constellations, these types of networks go into a “search” mode. Where passing satellites try to triangulate your transmission signal based on signal strength as they approach or leave your area. This allows networks like Global Star and Iridium to give a rough area (of a few miles) where the signal came from, even if the GPS coordinates are not able to be sent. These type of “searches” can take anywhere between 30-120 minutes depending on satellite orbits. The S&R teams are usually able to get a 1-4 mile search radius after these searches are finished by the satellites. That's pretty damn good without GPS coordinates!
ACR/ Personal Locator Beacon:
PLB’s run off global weather satellites, which are higher orbit devices. Most of these devices run a higher signal strength, because they have to send it further. The huge plus is that with the satellites sitting overhead longer, your signal can be pinpointed pretty quickly, if you have a clear line of sight to the skyline. The major downside to the PLB’s is if you are stuck in a canyon in Idaho, and the GWS (global weather satellites) are running in an orbit south of you, there is no signal getting out, period. This is why PLB’s are often more heavily used by ocean going travelers and less by adventure back country folks. Not saying that they are not useful, but if you spend a lot of time riding in the back woods in canyons and valleys, this is just good information to have.
With this information I’d probably make the switch over to a Garmin device. Knowing that some sort of signal would likely get out, and then a rough location area even if there was no GPS is better than nothing. Pair that with ability to pay per month, it’s a pretty cool little service. (I'm not even touching on the 2 way messaging)
The Search and Rescue feller also had some other viable options, running Spotwalla on your phone, sharing the link with family members is a free and pretty accurate service. But you just have to remember to keep the phone charged and on. But again, that’s only good for places you have cell reception. This allows family members to simply make sure you’re still moving day in and day out.
He also came with the option of a HAM radio or CB setup. While this is not too common out in this part of the country, CB radios are all over the rest of the country. There are usually emergency frequencies programed into CB radios. It turns out that the S&R leader is also a HAM radio expert, and suggested that as another option, but I am not sure that would work because HAM radio operators are somewhat a dying breed and require specific repeater dialing to work, and then hope someone is listening.
Sorry for the long winded post, but this was cool information to me and thought it could be interesting to others as well!