Search for missing British hiker in France called off after five days
The retired doctor texted his family to say he had fallen but has not responded since. It is thought his phone may have run out of battery
The authorities were unable to locate Tom Doherty's phone
Clare Carlile / X
The search for a retired British doctor has been called off after five days although the investigation into his disappearance will continue, a public prosecutor advised AFP.
The police search crews using dogs and helicopters were unsuccessful, partly because of foggy conditions.
Tom Doherty, 67, disappeared last Tuesday after sending a message on Whatsapp to his family saying: “Help, I’ve fallen and I can’t move.”
His car was found at the Col d'Escots in Ariège and what is presumed to be his tent but there has been no trace of him since then.
Read more: Search for British hiker missing in south-west France
Untrackable location
Mr Doherty did not share his location with his family, despite texting them a message on Tuesday evening.
Authorities have been unable to locate his phone, possibly because its battery life has expired and / or because it is out of signal - the area does not have good mobile coverage.
The family is also trying to access his Mac computer in order to view his Apple account, and have asked for help via social media. This may allow them to track his location by either seeing where his latest photos were taken, or via the ‘Find My’ app which tracks an iPhone’s location.
However, they have been unable so far without his password. When The Connexion contacted Apple services, they said that the family should contact them to see if they can help.
There are other ways to locate a phone but this must have been set up beforehand or requires a connection to a satellite, have signal or be connected to Wi-Fi.
A tracking system invented in the UK that is now implemented in France automatically tracks the location of a phone that calls emergency services and is accurate to around 50 metres some 85% of the time, using a mixture of GPS and other connections available.
It then sends a text to authorities with the location, but it only works with Android phones for the moment (Mr Doherty has an Apple phone) and only when a call is connected.
A phone can be tracked using its GPS signal, which is connected to satellites and therefore does not require a mobile signal, but again this must be installed beforehand.
Read more: Portable internet service Starlink Mini is now available in France
Once a phone is switched off, it can no longer be tracked because it no longer sends or receives any signals. Some tracking systems, like ‘Find My’, will show the last known location.
When a phone is identified via its mobile signal the location may not be wholly accurate as it is tracked using nearby towers that may have received its signals. However these are not necessarily the closest towers.
For example, the signal to the closest one may be blocked by trees or mountains, so the signal may be picked up by a tower which is further away.
