UKC

Does anyone know what transmitters are available to use in situations where one is alone and needs help, but there's zero mobile signal within any realistic range?

Spot ( http://www.findmespot.eu/en/ ) do this and the price seems reasonable. It allows you to check in, report locations and send for help/rescue if needed. The price is £125 for a transmitter and £115ish per year for a subscription to the service.

I wanted to see if there was anything else out there that the UKC community thinks is worth considering.

NB - the use (not by me) would be for someone doing fieldwork alone in the Yorkshire Dales who's walking up and down a river catchment area putting natural dams in tributaries. So there's plenty of potential for slips, trips and falls. The only place mobile signal has been found close by could mean an hour of walking to the car and a short drive to the signal so it's not ideal.

In reply to James Malloch:

Not sure what the UK support is, but a 406mhz PLB is made to a higher specification and does not require subscription. However does not have check in option.

In reply to tjin:

Thanks - I'll pass the information on. A quick search suggests it could be pretty good as an option.

The check in facility would be a nice to have really, emergency situations are the main priority.

In reply to James Malloch:
https://www.walkhighlands.co.uk/news/keeping-in-touch-personal-locator-beac...

In reply to James Malloch:
We've been using the Delorme (now Garmin) inReach systems in the arctic for a while, to replace expensive satellite phone units.

https://explore.garmin.com/en-US/inreach/#subscriptions

They are useful devices if you use them enough i.e. daily field use or extensive expedition use, but expensive as a 'just-in-case' measure.

You would be looking at £3-400 for a unit and anything from £13 per month to £90 per month for the subscription.

Though a far simpler method would be to employ a field assistant...

In reply to James Malloch:

Might be talking nonsense as I've not played around with it, but, is that not the facility offered by the "becon buddy" app in viewranger. My understanding from a quick look is that it allows your "buddy" to track your phone using GPS independent of the mobile signal. Might not be official enough though if your looking at Health Safety and Welfare at Work.

In reply to Hyphin:


No. That requires that the phone has active Internet connectivity - which will, of course, normally be being provided via the mobile network. See http://support.viewranger.com/index.php?pg=kb.page&id=111

In reply to James Malloch:

The Link is really useful for showing the comparison, thanks!

And the Delorme sounds great though I think a PhD budget won't stretch unfortunately...

Hyphin- we looked into that as I've definitely used my phone for GPS whilst not having any signal. It turns out that phones have GPS receivers but not transmitters so can't be used to relay any information without phone coverage also.

In reply to James Malloch:

You can use these type of PLB's inland now, https://www.marinesuperstore.com/safety-beacons/plb-ais one off payment no annual plans needed. They only send and can't receive, basically you break the plastic cover unroll the antenna and press the button. It sends an SOS and your position. Batteries last seven years (I think).

In reply to James Malloch:


Nothing, other than GPS satellites or jammers, transmits GPS signals. GPS for users is receive only, and the GPS satellites are transmit only.

Emergency beacons such as you are considering receive GPS signals, compute a position, and broadcast that position using some other radio system. Mobile hones would receive GPS, and transmit your position using the mobile phone data network.

Spot is a possible candidate, but, due to the use of geostationary satellites for its message relay, it can be prone to blockage if used in mountainous locations; the mountains block the line of sight between SPOT unit and the satellites. The further from the equator you go, the worse this gets.

In reply to captain paranoia:

Spot is a possible candidate, but, due to the use of geostationary satellites for its message relay, it can be prone to blockage if used in mountainous locations; the mountains block the line of sight between SPOT unit and the satellites. The further from the equator you go, the worse this gets.

I've not found this to be a problem (I have a DeLorme, now part of Garmin). I've used it in Northern Sweden as well as Scotland. I found in Sweden it took about 3 minutes for a text message to get through. I suppose it depends where you are and how many satellites are around you, but unless you're down in the bottom of the Grand Canyon signal blocking shouldn't be a problem.

In reply to captain paranoia:

Spot is considered so marginal for NZ that the advice is not to consider it an emergency device, rather negating most of its purpose. The issue is it tries 3 times to send then stops, and you won't know if it was successful.
I use an ACR ResQLink PLB here. I'd like to justify a Delorne Inreach for the messaging, but the amount of use I'd get out of it probably doesn't justify the cost.

In reply to OwenM:

DeLorme isn't SPOT, though, is it? It uses iridium as the message bearer service. Iridium isn't geostationary, so doesn't suffer the obscuration problem of equatorial orbit satellites.

In reply to captain paranoia:

So what does SPOT use?

In reply to OwenM:

SPOT uses the Globalstar network AFAIK. I've got a DeLorme inReach - it's a great device. I had my reservations about buying it at first, but I found that it basically replaced my need for using my satellite (although I'd still have that as a backup if I'm in the situation where I need/might want two devices). Being able to pair the DeLorme via Bluetooth to their explorer app (or whatever it's called) is also pretty handy for the added navigation features and sending/receiving customised text messages more efficiently.

In reply to captain paranoia:

https://en.wikipedia.org/wiki/Globalstar

Globalstar is a low Earth orbit (LEO) satellite constellation for satellite phone and low-speed data communications, somewhat similar to the Iridium satellite constellation and Orbcomm satellite systems.

They both use satellites, which are generally up in the sky, so the signal goes up - not along the ground. Mountains getting in the way is unlikely to be a great problem with either system.

In reply to OwenM:


The issue being alluded to is that the satellites in question won't necessarily be directly overhead; and in addition, might be in low orbits (certainly that seems to apply to the Globalstar ones you've referenced) - so occlusion of the signal by mountains etc. is indeed a potential problem.

The comments above by damowilk - regarding the unreliability of Spot in New Zealand - are interesting; it would be good to understand the exact reasons there.