Some of the time confusion arises because GPS units can report a variety of "GPS Time", "UTC" and semi-corrected GPS Time. I discovered this when building a precision timer for an industrial corrosion monitoring device.
On startup the GPS would report UTC plus one second. Within 12.5 minutes it would report exactly UTC, i.e. after reception of the GPS/UTC correction factor. I could only assume that the GPS developers had pre-programmed in the UTC/GPS clock offset that was current when the device was manufactured. Since then a UTC leap second had been added. Importantly, there is no way to tell which of those times the GPS is reporting. No doubt the precise behavior varies from chipset to chipset. For my project I was using a SiRF III receiver and could switch on the raw 50bps data steam and watch for the GPS/UTC correction to be sure when I had UTC time. AFAIK, there is no way of doing that on Android, so for truly accurate times your best bet is to leave the GPS on for 12.5 minutes before reading the time, and hope that it has successfully received the clock correction. -- Andrew -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
