GNSS Almanac Purpose RNAV

If the data for the visible satellites is stored each time a GNSSGNSS —Global Navigation Satellite System unit is switched off, then when the unit is turned on again in a similar location it is likely the same satellites will be in view, and therefore a fix can be obtained more rapidly. You may have noticed that after you take a long haul flight, that your phone or other device takes a lot longer to establish its location. This is why - it needs to download the Almanac data for the "new" satellites and so takes longer.