Reply to post: Re: RTFM

Fun fact: GPS uses 10 bits to store the week. That means it runs out... oh heck – April 6, 2019



Looks like the IS-GPS-200 documents 2 frequencies called L1 and L2. L2 fixes this but is a different frequency : and (for "frequency")

"1575.42 MHz (10.23 MHz × 154) called L1;

and a second at 1227.60 MHz (10.23 MHz × 120), called L2."

CNAV is wrapped up in L2 but L2 is "pre-operational" and not to be used for critical usage.

L1 C/A (under "Legacy Signals" in Wiki has a section about 10 bits and rollover) is affected. L2C CNAV ("pre-operational") is not (blurb in wiki under "CNAV navigation message" explains increase in bits). was also helpful.

Sounds like some newer receivers are on the L2 bandwagon.. but that doesn't mean there isn't a tonne of L1 only devices still around.

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