[time-nuts] Compensating phase differnces in dual frequency GPS receviers?
pmonta at gmail.com
Thu Dec 1 22:56:12 EST 2011
> So, that'd mean there would be an automatic calibration system inside
> the device, because i dont have any equipment with which i could
> calibrate delays over a temperature range.
I suppose they could do that---provide a weak broadband source (say a
comb) combined with the antenna signal prior to the channel filters,
and provide a reference channel for this calibration signal to compare
against on-line. Or they could calibrate just once at production
time, which would be less expensive---the system would then compensate
open-loop based on temperature.
> Nice disertation, but i cannot see how you come to the conclusion
> that this temperature coefficient is from the input RF chain.
> The measurement shows only a general time shift of the whole device.
> And the author does not draw any conclusion from it.
Well, it would have to be the front end. DSP doesn't drift with temperature.
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