Navigation: Part 3

Security and Privacy

It is pretty unlikely that this really concerns many people on the HRP, but I'll cover it for completeness.

There is a fundamental difference between using a GPS and using an iPhone (or similar) as a GPS, which has nothing to do with accuracy, interface, or network availability. A GPS is only ever a receiver and a low-power one at that. 

Therefore it cannot send your location to anyone else, now or in the future. Anyone who is close enough to pick up (and interpret) the faint electromagnetic waves from its operation is already as it were "having this conversation face-to-face". 

The only data it records is what you yourself have asked it to store, with the exception of its last known position. We can deduce this as the map first displays this location until it gets a new fix.

So if you do not want the device to hold where you have been do two things:

- Do not store locations or automatically record tracks (there is a setting for this in Setup)

- When in some "neutral" location: Power it on, wait for a satellite fix and then power it off.

My GPS has no locking/PIN mechanism so anyone with physical access to the device can read the data. Any data you have placed on the Micro SD card is also easily readable. 

I added my name and email address to the boot-up screen (there is a text file on the device that you can edit). This is of course optional. It would be useful if you lost your device and it was found by an honest person. You may wish to use an anonymous email address instead of your primary personal one.

Some higher level models of Garmin GPS (eg eTrex 30) can transmit data to another Garmin, but this is another face-to-face operation. Possibly someone has worked out a method to suck data from such a GPS, but it would need to be turned on and at close range. So if you frequently use the GPS to store the locations of buried treasure.

If using an iPhone as a GPS you would be well advised from a purely power consumption point of view to remove the SIM card, but there is still no way for most people to know, even less control, what the device is storing and may choose to send back "home" when it next has connectivity. If you are in an area where there is connectivity and you keep the SIM card in you may wish to consider the advisability (or not) of having others (ie for all intents and purposes the world) know where you are. There is a good discussion on the "Adventure Alan" pages about using the iPhone as a GPS. 

There are some pluses and minuses you must weigh up. For example if you needed to make an emergency call it would be painful (perhaps literally) to have to find and insert the SIM card, and yet having it out makes much more sense in most use cases.

In the context of the HRP this is all probably not much of an issue. All the locations I have stored are ones that I intended to share ab initio. However the wisdom of constantly sharing your present location is something that has received much attention and engendered considerable debate particularly on some of the long trails in the US.