Le 16 août 2013 à 15:34, David Taylor a écrit : > On 16/08/2013 13:02, John Hasler wrote: >> David Taylor writes: >>> A pity that they haven't been able to find two or three spare bits to >>> reduce the 1024 week ambiguity to nearer a half-century or even 100 >>> years. >> >> From the Wikipedia article: >> >> To determine the current Gregorian date, a GPS receiver must be >> provided with the approximate date (to within 3,584 days) to correctly >> translate the GPS date signal. To address this concern the modernized >> GPS navigation message uses a 13-bit field that only repeats every >> 8,192 weeks (157 years), thus lasting until the year 2137 (157 years >> after GPS week zero). > > Oh, that /is/ good news, John! Many thanks. I couldn't see that from a > quick scan of the referenced documents, so that's most helpful to know. > > I wonder whether there is any way to determine which satellites are sending > this modernised message, perhaps they all do, or whether a particular > receiver is using the full 13-bit field? It's something I've not seen listed > in various specifications I've read, but perhaps it's taken for granted after > a certain date? > --
I read that it was part of the L2 signal stream. So you would need an L2 receiver but that wouldn't guarantee that the firmware is using the full field. > Cheers, > David > Web: http://www.satsignal.eu > > _______________________________________________ > questions mailing list > [email protected] > http://lists.ntp.org/listinfo/questions _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
