[RossBencina]

> jitter of about a few hundreds nanoseconds

The 1PPS output may have that much jitter (due to it being clocked synchronously with the module's system clock) but I believe there is usually a way to query the device for the error between the 1PPS signal and the actual idealised pulse time.

Sylvain Munaut made a project using a high resolution TDC/time of flight converter to discipline another clock against the GPS idealised pusle time. I can't find a link right now unfortunately.

[tverbeure]

Yes, this feature exists, but it's usually only present on GPS modules that are sold specifically for time keeping instead of location tracking, such as the uBlox LEA-M8T.

They are much more expensive, think $100 instead of $10.