Preparation for GPS receiver initialization

You really don’t need to know this technical information to operate your GPS receiver, but to start acquiring satellites to get an accurate location fix, a GPS receiver needs the following satellite data:

• A current almanac (rough positions of all the satellites in orbit)
• The GPS receiver’s current location
• The current date and time
• Ephemeris data (precise position of individual satellites)

If some or all the data is missing or out-of-date, the GPS receiver needs to get updated information from the satellites before it can accurately fix a current position. The types of data that are outof-date or missing determine how long the GPS receiver takes to initialize. If the GPS receiver is brand new, out of the box, several hundred miles away from where it was last used, or has been stored for a prolonged period of time, initialization will take longer.