[time-nuts] ublox NEO-M8T improved by insulated chamber?

Tom Van Baak tvb at LeapSecond.com
Wed Nov 8 12:31:01 EST 2017

> How exactly do you measure offset of your GPS time output to absolute UTC time?

Conceptually it's no different from measuring your favorite resister or thermometer: you compare your DUT against a standard REF and the difference is your error, a process called calibration. So the same is true for SI second (time interval, frequency) and UTC (time epoch). As I mentioned earlier, calibrating your SI second is quite simple. Calibrating your UTC is harder.

Here are couple examples:

(1) Years ago fellow time-nut Doug loaned out his and my antenna/receiver to be calibrated. The report will give you an idea of what's involved:

"Absolute Calibration of a Geodetic Time Transfer System"

(2) Here's classic report from fellow time-nut Rick:


(3) In both cases above there is transport of equipment involved. But the equipment can come to you instead:

see also
and a nice photo of the traveling time van:

(4) NIST also offers time & frequency calibration services:


"A NIST Disciplined Oscillator: Delivering UTC(NIST) to the Calibration Laboratory"

"Remote Time Calibrations via the NIST Time Measurement and Analysis Service"

That's enough reading to keep you busy for a few days.


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