GNSS STS RNAV

If a GPSGPS —Global Positioning System (USA) unit is being turned on for the first time, or has moved a long way across the globe, the stored Almanac data will be invalid for the new satellites it has in its field of view. Consequently, it has to "search the sky" for the new satellites it can see and download the new Almanac and other data from them prior to use.