No. GPS time is maintained as WEEKS since the GPS epoch and an offset into the week (TOW -- time of week). There is an additional field that is the "offset from UT1" (currently 11 seconds I believe). The receiver uses the information to calculate UT1. There is, I believe, a flag that says that the "offset" is to be incremented at the end of the current day, and that provides all the information necessary to calculate UT1, UTC, and the leap flag.
--- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. >-----Original Message----- >From: sqlite-users [mailto:sqlite-users- >boun...@mailinglists.sqlite.org] On Behalf Of Wout Mertens >Sent: Saturday, 9 June, 2018 06:22 >To: SQLite mailing list >Subject: Re: [sqlite] Selecting multiple similar columnname. > >So the satellites don't get leapsecond updates? I don't understand >why it >can't just be an epoch… > >On Sat, Jun 9, 2018, 8:39 AM Stephan Buchert <stephanb...@gmail.com> >wrote: > >> To take care of the leap seconds every ~1.5 years or so, you need a >day >> segmented time stamp and a three column primary key: >> >> CREATE TABLE satlog ( >> sat INTEGER, >> day2000 INTEGER, -- days since 2000-01-01 >> msec INTEGER, -- milliseconds of day, just in case we ever >have to >> deal with subseconds >> snr REAL, >> elevation REAL, >> abc REAL, >> def REAL, >> PRIMARY KEY(sat, day2000, msec) >> ); >> >> To find satellites and timestamps with SNR>30: >> >> SELECT sat, datetime('2000-01-01', day2000||' days', (msec/1000)||' >> seconds') FROM satlog WHERE snr>30; >> >> I'm using similar as this,with now more than 4 years of 1 s >satellite >> data. Sqlite performs very well with a schema like this. >> >> (Your stream must of course be able to encode the leap seconds, >otherwise >> you cannot do anything on the Sqlite level. The GNSS satellites >will send >> data strictly at every s). >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@mailinglists.sqlite.org >> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite- >users >> >_______________________________________________ >sqlite-users mailing list >sqlite-users@mailinglists.sqlite.org >http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
