4 ms·
Note that GPS week number is now 13 bits long since the introduction of CNAV navigation message format; devices only accepting the original NAV format are now p
by lifthrasiir 4y ago
Note that GPS week number is now 13 bits long since the introduction of CNAV navigation message format; devices only accepting the original NAV format are now pretty rare.
- defrost 4y agoSure, the seconds are still lapsed seconds since (weekly) epoch . . . (Not to mention the post corrections broadcast upwards from the ground to adjust for relativistic time drag between Earth surface nominal 1G and sat orbit height gravity) Point being, many timing applications use lapsed time since X counters and are part of systems designed to handle rollover. The mindset of just adding more bits to a counter or recording more decimal points isn't always appropriate or the 'best' fix.
- dreamcompiler 4y ago> to adjust for relativistic time drag between Earth surface nominal 1G and sat orbit height gravity That's just the General Relativity correction. There's also a Special Relativity correction to account for time dilation caused by the satellite's speed, which works in the opposite direction to the GR correction yet the two don't exactly cancel each other. Plus there are some others (Doppler shift, Sagnac effect, etc.) https://www.aapt.org/doorway/TGRU/articles/Ashbyarticle.pdf https://www.aapt.org/doorway/TGRU/articles/Ashbyarticle.pdf