Emergency calls via cell phone

I could be wrong but I thought it was that if your phone had no access to your network but could pick up another network then you could make an emergency call if needed.

Life flight etc do have gear that can lock onto a cell phone if it is active but its strictly line of sight stuff. They have to already be fairly close. For anyone to get a fix on you you have to have some sort of signal ie a proper cell site or a pseudo site like on the helicopter. No reception is exactly that but texts can get through with less signal than voice calls. All the networks in NZ use the same technology now so if you have coverage from any carrier an emergency call ie spark phone on vodafone or 2 degrees etc can be made but that doesnt help if they want to call you back

absolutely not the satellite GPS connection on your mobile cell phone is a receive only technology. it can not transmit to a satellite you need a connection to a land based transceiver for any chance of your location to be tracked its claimed in some instances when your phone shows no connection there may be a residual connection to record your position, sometimes you send a text and it says it didnt send but it may have been sent in reality.... but you cant rely on it if your connection is that bad you shouldnt be relying on your cell phone for connection at all. most of the land where nz mountains are on DOC land have no cell phone connectivity at all. anyone with a decent amount of tramping experience will be able to tell you that,.. you must have a dedicated satellite phone or satellite gps tracking device to transmit to a satellite... they need much more batteries than a cell phone to do so

As said before: - GPS is receive only - you can be located (precision is a couple hundred meters usually) using the radio waves of your phone, this is what government agencies use to track fake tower sites, jammers, illegal radios, etc. but this is expensive and slow, I'm not sure SAR is using that kind of stuff I think what he meant is that you can make an emergency call if you are out of coverage of your home network BUT have coverage from another network. For example if you have a Spark SIM card but no coverage, but you get signal from a Vodafone tower, your phone will display "Emergency calls only". But this is not really something you should rely on in the bush, because most likely, if you are out of coverage for your home network, you are probably out of coverage for other networks too, especially in NZ with the poor coverage and the fact we only have 2 networks.

Don't quote me, but I heard that sar have ( or have access to) portable mini cell towers to use in searches. Basically another tool in the belt. I can't remember where I heard this so can't advise on how true it may be. It may be the stuff covered above.

Any cellphone that is on is sending out a regular signal to try and locate a cell phone tower. If its on and you're deep in a fiordland valley, it will still be putting out this signal. Devices exist that can pick up these signals, USA police and FBI, CIA and the like use them to spy on people. They can pick up and track, localize the signal from a cell phone as long as it is on, independent of whether it has GPS or the GPS is on or not. See Stingray Phone tracker: https://en.wikipedia.org/wiki/Stingray_phone_tracker If SAR had one of these in a helicopter and was over the area where someone was lost, they'd be able to pick up their location if their cellphone was on, provided the helicopter or aircraft was line of sight to the phone, even in a remote alpine valley, even if the person was dead or incapacitated. Do SAR have these devices or similar that they can use it this way, if not why not? It would be nice if there was a passive mode only / no spying capability version that SAR could use. It seems to me that virtually everyone has a cell phone with them in the mountains now days, if people knew that their mobile would help in locating them once SAR was looking for them, they could conserve battery power until it was clear / likely SAR was looking for them then turn their phone on. Much better to have a PLB of course, but this capability could well have helped in 3 or 4 situations in the last while where people have got lost on day trips but it's still taken a while to find them.

inadviseable to have your cell phone out of airplane mode when tramping if you dont need rescuing, if there is little or no cell pone reception the phone will transmit at maximum power to try and establish a connection and the batteries will run flat faster, cell phones are designed to use the minimum power necessary to maintain a connection, if reception is good your battery will last a lot longer

"Do SAR have these devices or similar that they can use it this way, if not why not?" I'm just guessing but if not then possibly a cost/benefit thing, or an issue with available expertise? There are heaps of technologies that Police and LandSAR could have access to that might help, but deploying it to be available on short enough notice in all areas where an incident might happen is probably less than trivial. Especially if it's not likely to be needed most of the time. For comparison the campaign to get anyone and everyone carrying a PLB has most probably been a carefully measured strategy where someone's determined it'd make a big positive difference to SAR op outcomes, so is worth the coordinated effort. Also much of the cost is outsourced to private users who have to buy PLBs they'll never use, and to helicopter trusts that rely on fundraising to keep their operations going, so it doesn't have to show up on public balance sheets.

Scottie-SAR ,certainly Methven SAR,don`t have mini-towers to aid cell coverage.Most SAR groups use VHF radios,which are line-of-sight communication.When we want to increase the range,we use a repeater,placed on a high point,so a VHF in a gully can use that to contact another radio within line sight of the repeater.And HF of course,still the best two-way coverage in the back country. I don`t rely on cell phone for communication in my tramping;I carry a GPS & where I want two-way comms,say for multi day trips,I`ll lug an HF(mountain radio)which will get out of 95% of places.