A-GPS = Assisted GPS based positioning
Without the help of A-GPS, more satellites would be needed, good visibility to the satellites, and more time to calculate the GPS device's own position
A-GPS improves the reliability of the device and makes it possible to calculation the device's position in faster pace than it normally would be able to. Especially immediately after starting the GPS device when calculating the first position information
Without A-GPS, the device could lose its position in difficult conditions and in very covered terrain or when being momentarily indoors, as the satellites would then not be available at all or at least not easily visible and readable
A-GPS can download the predicted position, orbit and almanac data of satellites for up to several days, making them available even if the device is disconnected from the mobile operator's network in between
In this case, when when ever A-GPS Online is available and used, in addition to receiving A-GPS data, the device also sends information back to the A-GPS server about its own location and the available and used satellites, and then the A-GPS server can send in return, more precisely targeted information to the device
A-GPS Online is optional, but it does speed up A-GPS and enables more accurate and reliable A-GPS data
Similarly, A-GPS is not absolutely mandatory in itself, as the Tracker's GPS device also has its own GPS, which can calculate the position information of its own location independently, if the conditions are met and satellites are readily available
Updating the A-GPS information used by the Tracker GPS device
After the device has downloaded the A-GPS file, the accuracy of the data is good, especially during the first few days, but gradually decreases as the days go by
For this reason, every time you switch on the Tracker GPS device, the device checks the A-GPS data and, if necessary, it will download a new and up-to-date A-GPS file from the A-GPS server
This doesn't require any action from user as the Tracker GPS device does it independently as a part of device's start-up procedures when power is switched on
If you notice Tracker GPS device has long delays in calculating its own position or some other problems arise, always check first that your device's software is up to date:
How can I update Tracker GPS device software?
Similarly, if the connection of the Tracker GPS device to the mobile operator's network does not work, it often manifests itself as problems with the Tracker Live service, and then it may also mean that it's not be possible to update the A-GPS data when needed to do so:
Why the GPS device has disconnections to Tracker Live -service?