Why does my Pawfit tracker sometimes take less time to get strong GPS but sometimes longer when outdoors?

Question

Why does my Pawfit tracker sometimes take less time to get strong GPS but other times longer when being outdoors?

Answer

The Pawfit tracker uses GPS to calculate locations. It needs minimum 4 satellites to calculate accurate locations. Any obstacles between the tracker and satellites can result in a longer calculation time. Therefore, the tracker normally takes less time to get a GPS location (fix) on sunny days, but longer on cloudy or rainy days. Once it gets the first GPS fix, the subsequent fixes should be much faster to obtain.

If the tracker has just been turned on, or has been indoors overnight, the time it takes to calculate the first GPS fix is longer - this is known as a cold start. 

Furthermore, to accelerate the time it takes to calculate a GPS fix, the tracker needs to update the Ephemeris data (current and predicted location, timing and health of GPS satellites) regularly. It also needs network access to download the update. If your tracker has not been turned on for a few days, or the mobile phone network is unavailable, the tracker will take longer to get the initial GPS fix.