I need a device which can remotely tell me its location, either in realtime or with some delay. So, I naturally googled for GPS transmitters. The top product has much too large a thickness (I need it so that, it can be undetected through a few layers of cloth on both sides).
Then I thought of a small mobile phone, with which I would use Android Device Manager to locate. But problem is, internet connectivity is gonna be scarce. Nonexistent. So not that, either.
Here's my situation:
A group of objects is going to be delivered to a group of persons, by means of placing said objects in a large sack, or similar. I need to track this sack. Therefore, I must place in it a device that transmits to me its location. Since it needs to be undetected, it must be thin. Since networks will be nonexistent, it must report over some other long-distance network, or, alternatively, store a list of locations every [30 mins/hour/few hours] which are transmitted when it finally reaches network connectivity. This device must have a battery life of a few days.
That it be undetected is imperative. Should it be discovered, there will be loss of life. The bags may be similar to this or this.
So, is either my GPS or Mobile idea usable? If not, can you suggest anything?