[time-nuts] Trimble Thunderbolt no longer determines thecorrect date

Mark Sims holrum at hotmail.com
Thu Jul 27 22:32:44 EDT 2017

Actually,  Lady Heather's rollover compensation code has no limit on the correction.  It can compensate for any number of rollovers.   In fact you can use it to adjust the receiver time by any number of seconds (including fractional seconds).   

The default behavior is to trigger after 10 seconds of consecutive time messages where the time is before year 2016.  The 10 second filter is to avoid false triggers from corrupted packets.   This means that for the first 10 seconds after starting Heather on a Tbolt,  the date will be wrong.  When rollover compensation is in effect, the date is shown in yellow and a "ro" flag appears next to it.   It would nice if somebody could come up with a patched firmware...  

You can get a false rollover detection if you start monitoring a receiver before it has acquired the almanac since most receivers output time based upon the GPS epoch if they don't have an almanac.   


> The current version of Mark's Lady Heather program has code to detect this and fix it so you're good to go for the next 19.6 years.

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