Since launch we have been making constant improvements to the Pure Firmware mainly centred around the management of GPS.
In firmware version .612 we modified the software to allow 0.5 second polling of the GPS antenna and to support the new GPS module being used in the Mk2. This means the GPS array reaches out to the satellites every half second, rather than once a second, This has the benefit of the speed changing visually on the PURE far smoother for both the Mk 1 and Mk2.
Customers may have noticed a small delay on the first use of between 5 and 10 seconds to acquire a satellite lock, but unless the Pure loses all charge, then this delay will not be seen again.
When the Pure is not used for more than 6 hours, the ephemeris satellite data is no longer valid. GPS satellites transmit information about their location (current and predicted), timing and "health" via what is known as ephemeris data. This data is used by the GPS receivers to estimate location relative to the satellites and thus position on earth. Under these conditions the Pure needs to have a clear view of the sky and the GPS antenna has to go through warm start process to acquire satellites. This can take between 30 seconds with clear skies and a couple minutes with cloudy skies.
In the event that a Pure is fully discharged, again the Pure will take up to 2 minutes to acquire a satellite lock as all the ephemeris satellite data is lost and the Pure will need to establish which GPS receiver it is using.