Trace lost cell phones?

vftt.org

Help Support vftt.org:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
C

Creag Nan Drochaid

Active member
Joined
Nov 5, 2009
Messages
342
Reaction score
42
In today's edition of The Scotsman is a story about two hillwalkers lost on Meall-an-t-Suidhe Wednesday night (that hill sits atop the north slope of Glen Nevis about halfway from the floor of the glen to the summit of Ben Nevis, maybe two miles from the town of Fort William). Lochaber Mountain Rescue traced their cell phone tracks and pinpointed their location, then went up and collected them.

My question is, assuming cell coverage, is this method of finding lost persons ever used here? Thank you.
 
NYS DEC Rangers regularly find distressed persons by Cell GPS signal.
For example, in recent a weekly SAR report, almost every week there is a similar story such as:

Town of Keene
Essex County
Search: On March 19, two men backcountry skiing on Mount Colden's Couloir Slide became disoriented and called 911 for help. The call was transferred to DEC Ray Brook Dispatch with the cell phone GPS location. Due to the accuracy of the GPS location, the dispatcher was able to tell the skiers how to get back on the trail. Within 30 minutes, the two reported they were back on the trail and no longer in need of assistance.
 
I guess the interesting question is whether a cell phone can be located using built-in GPS if the phone owner has not called 911 ? I think there are apps that are capable of periodically posting cell phone location to the Web, but the real useful thing would be an app that could enable phone GPS if it were not on and send its location via text message. I would have no problem in terms of security to allow my wife or someone else to text me a special PIN that would trigger my phone to text back my location.
 
Of note, even prior to GPS being available on phones, a rough location could be estimated based on which towers a phone signal did or did not reach. This was usually too broad to really help with SAR, but it was used in forensics to estimate where a call originated.
 
I am able with my Android phone to find it. It's done by logging into your Google account and go into your sign in and security settings. Then tap find your phone. It will show you using Google maps where it was last seen. A new feature that has been released for Google maps that I'm not familiar with yet will let you share your location with select people for a limited time. So while maybe not lost. You could give loved ones peace of mind while you are tramping. Assuming strong cell coverage of course.
 
In the Apple-verse, these things are accomplished with the "Find My Phone" app or iCloud feature, and location sharing.
 
Keeping it on, or even on standby waiting for that pin from iAmKrysz' bride, I would imagine still drains the battery. The availability of a signal and battery life are obstacles to my relying too much on the technology.
 
Most phones burn up far more power when in fringe areas where cell service is intermittent as they apparently are repeatedly trying to reconnect. There are hiking aps designed to be used in airplane mode that operate off of the memory of the phone to extend battery life.

Given all potential back doors to cell phones I expect the only way to really go off the grid is to physically remove the batteries, of course on most new cell phones the batteries cant be removed.
 
As some of you pointed out there is functionality that comes relatively close to what I asked about. Coincidentally, this morning I came across an article about a new position sharing functionality in google maps that is being rolled out (which thegibba already mentioned): https://www.engadget.com/2017/03/22/google-maps-location-sharing/. The article also mentions apps like Waze and Glympse that can also share location.

So here is my take on these options:
  1. I could be wrong but they all require a data connection. In my experience mobile data is a big drain on my phone battery, so I purposefully turn it off when hiking but that cuts out any option that needs Internet connection. I also think in some areas it is possible to have cell signal but no usable data connection.
  2. Find My iPhone requires high level of trust - I wouldn't share my Apple or Google password with just anyone.
  3. I don't know if google maps will require location services to be enabled all the time. Again, I usually keep my location services disabled because I don't want to drain my battery and I don't want all the apps I have to constantly spy on my whereabouts. I hope that Google works it out and adds an option for example to wake up GPS only every so often e.g. every 15 or 30 minutes and also add a way to send location via text, a bit like Spot can do for some functions right now.
 
Last edited:
iAmKrzys said:
As some of you pointed out there is functionality that comes relatively close to what I asked about. Coincidentally, this morning I came across an article about a new position sharing functionality in google maps that is being rolled out (which thegibba already mentioned): https://www.engadget.com/2017/03/22/google-maps-location-sharing/. The article also mentions apps like Waze and Glympse that can also share location.

So here is my take on these options:
  1. I could be wrong but they all require a data connection. In my experience mobile data is a big drain on my phone battery, so I purposefully turn it off when hiking but that cuts out any option that needs Internet connection. I also think in some areas it is possible to have cell signal but no usable data connection.
Click to expand...
The locations used by apps and tracking for commercial purposes usually use the GPS in the phone. The GPS locations would be sent by a data connection or as side data as part of a voice connection. (Digital voice is, after all, just another form of data...)

The non-GPS methods use such techniques such as signal time-of-arrival at or direction from multiple towers and don't depend upon a particular connection type or any cooperation from the phone. (The phone only needs to make a connection*.) These techniques are typically only used in special situations such as locating lost people. (For instance, such techniques were used to locate the climbers trapped near the top of Mt Hood several years ago when one was able to make a short connection.) They are less accurate than GPS locations. (There is more detail in the article linked in my previous post.)

* You don't need to intentionally use the phone--it only needs to be turned on. They make periodic connections to touch base with the nearest tower so the cellphone system knows how to direct incoming calls. The system is always tracking active phones to link them to the nearest tower. However, this level of tracking isn't very accurate, particularly in the country where the towers tend to be far apart. (The phone must be in active mode--airplane mode turns the radio transmitters off.)

Doug
 
Last edited:
@iAmKrzys

Just to give you an idea of what some backcountry navigation apps are doing with regards to sharing one's location:

I am using Locus Map (Android) and you can easily share your current location via SMS (a non-"data" connection), or email, or whatever messaging app you may have on your phone.

Currently in beta is the ability to share your "live location" which is the term they use to live-stream your location to someone ("live" as in periodically; every few minutes). The recipient gets an URL to a map showing your location (in their browser). This is a premium, paid service and I do believe it uses a data connection to make this happen (i.e. it doesn't work via SMS).

These two features (and more sharing options) are described here: http://docs.locusmap.eu/doku.php?id=manual:user_guide:functions:share


Locus Map also allows you to do live tracking other ways (although all require a data connection).

1) Public Locus Tracking
Free. You sign up and allow your position to be visible to all other Locus Map users (in Locus Map, not in a browser).

2) Private Locus Tracking
Paid service. You sign up and allow your position to be visible to a chosen group of Locus Map users (in Locus Map, not in a browser).

3) Web Services
Display your location on GPSies.com.

4) Custom live tracking
Choose what you want to share (Lat/Long, Altitude, Speed, Bearing, Time, etc) and it'll send the data to whatever web-service you want.

The tracking features are described here: http://docs.locusmap.eu/doku.php?id=manual:user_guide:functions:live_tracking


There are also many apps exclusively designed for sharing one's location with others:
Google Play Store: https://play.google.com/store/search?q=send my gps location in text&c=apps

I imagine there are many similar apps for iOS as well.
 
Last edited:
Keep in mind. Airplane mode does not typically disable the GPS. (In any phone I've used). You can use your hiking/tracking apps to keep tabs on your movements while in airplane mode whilst reducing battery load. You will of course not be able to see map data that isn't pre-cached.
 
I went hiking today in Sterling State Forest Park and had no cell phone signal in most places. This reminded me why I got Spot.
 
Nessmuk said:
NYS DEC Rangers regularly find distressed persons by Cell GPS signal.
For example, in recent a weekly SAR report, almost every week there is a similar story such as:

Town of Keene
Essex County
Search: On March 19, two men backcountry skiing on Mount Colden's Couloir Slide became disoriented and called 911 for help. The call was transferred to DEC Ray Brook Dispatch with the cell phone GPS location. Due to the accuracy of the GPS location, the dispatcher was able to tell the skiers how to get back on the trail. Within 30 minutes, the two reported they were back on the trail and no longer in need of assistance.
Click to expand...

<very mild sarcasm>Does this mean an electronic device prevented a search and rescue effort?</very mild sarcasm>
 
thegibba said:
Keep in mind. Airplane mode does not typically disable the GPS. (In any phone I've used). You can use your hiking/tracking apps to keep tabs on your movements while in airplane mode whilst reducing battery load. You will of course not be able to see map data that isn't pre-cached.
Click to expand...

Yeah, I've forgotten to pre-cache a couple times, which is annoying. Thankfully, I don't have to cache much before a hike, as I usually stay in a fairly small area (maybe 100 square miles), so it's easy to cache.
 
You must log in or register to reply here.

Similar threads

arm
Scotland - Ben Nevis
Replies
9
Views
4K
ChrisB
ChrisB
E
Beacon rescue
Replies
17
Views
16K
pondhopper
P

Latest posts

Top