The Difference Between GPS Cold Start And Hot Start

- Apr 18, 2018-

GPS module generally supports Cold start and Hot start modes (Note: warm start is not discussed)


     Generally, the cold start time is much longer than the hot start time. Take the signal as good enough as an example, the hot start of the SirFIII is within 15 seconds, the cold start is within 42 seconds, and the signal is weak, the longer it takes. Warm start conditions as follows:


     (1) The location information (latitude, longitude, altitude) before the last shutdown was known (so the next shutdown in the garage must have been a cold start);

     (2) The current time, calendar, and ephemeris are known (requires real-time clock support, E666 support)

     (3) The distance from the last shutdown was not more than 4 hours (the ephemeris changes when the time is too long, ie the previous satellite cannot see it)