Re: [time-nuts] Truetime XLi sat signal levels (dBW to dBc/SNR conversion question)

Hi Mark & David, Perhaps this article is useful for the discussion. https://insidegnss.com/measuring-gnss-signal-strength/ /Björn Sent from my iPhone ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to

Re: [time-nuts] Truetime XLi sat signal levels (dBW to dBc/SNR conversion question)

On Sat, Jun 15, 2019 at 05:21:17PM +, Mark Sims wrote: > The 30 dBc refers to the signal level reported by the Ublox. If the > Ublox falls below around 30, the Truetime will be reporting -196 dBW. > That seems to be the cutoff threshold for its idea of a "good" signal... > it does not

Re: [time-nuts] Truetime XLi sat signal levels (dBW to dBc/SNR conversion question)

Mark, When you refer to "30 dBc", what is that? Is it the eb/n0 value? If so, with the XLi's behavior as you report it, your scheme would fail over most of the useful signal range. And, it will probably differ from setup to setup of the HW, depending on all the parameters that have already

[time-nuts] Truetime XLi sat signal levels (dBW to dBc/SNR conversion question)

I have figured out an empirical formula for mapping between the TrueTime dBW values and the more traditionally reported signal level values. I ran a Ublox F9T and the TrueTime in parallel off the same antenna. By comparing the TrueTime and Ublox sig levels a rather trivial mapping function

Re: [time-nuts] Truetime XLi sat signal levels (dBW to dBc/SNR conversion question)

According to this reference the minimum received power on Earth should be -158.50dBW. According to this XLi manual the expected antenna gain should be between 20 to 36dB, so the reported received signal should

Re: [time-nuts] Truetime XLi sat signal levels (dBW to dBc/SNR conversion question)

On Fri, Jun 14, 2019 at 01:05:21AM +, Mark Sims wrote: Since nobody else has stuck their neck out to speculate... I will. I do not pretend to know for sure exactly what TrueTime means. > Pretty much all GPS receivers report sig levels in dBc or SNR type > values in the

[time-nuts] Truetime XLi sat signal levels (dBW to dBc/SNR conversion question)

I am adding Truetime XL and XLi support to Lady Heather. Pretty much all GPS receivers report sig levels in dBc or SNR type values in the range of around 20 .. 50. The Truetime XLi reports them in dBW with a range of around -196 to -145 dBW). Does anybody know how to convert the dBW