Can I use GPS without a mobile network connection?
Yes. The GPS in your device is separate from the cellular transmitter/receiver. Your mobile device will still receive a GPS signal without a phone signal. On an Android device, your GPS will work when the device is in flight mode. On an iOS device, your GPS will not work when the device is in flight mode.
How do I get the most accurate location?
You should aim to record a geolocation of < 10m by making sure you have a clear view of the sky, and allowing sufficient time (approx 10-15 seconds)to obtain an accurate position before saving the record. If your GPS is activated after being dormant for an extended period, and you have changed location (i.e. new country) it may take up to 2 minutes to achieve an accurate location for the first time.