Hi I can’t think of many antennas (multi band or single band) that claim to know their delay to < 5 ns. Simply having a *differential* delay spec of < 5 ns is quite good. Same thing with delay ripple, you see specs out to around 15 ns on a lot of antennas. None of this is getting you to the actual total delay of the antenna. It’s a pretty good bet that number is a bit larger than either of these.
Some of the ripple probably comes out in the standard modeling. I’m not sure that the differential delay is taken out that way. Total delay, not taken out in any obvious fashion ( at least that I can see). If the F9 has a built in antenna database, that’s not mentioned in the doc’s. Any benefit from the corrections would have to be part of post processing. No, that’s not the same as talking about the F9 it’s self doing X ns, but it would be part of any practical system trying to get close to 5 ns absolute accuracy. 5 ns *relative* accuracy between two F9’s? I probably could buy that if the appropriate one sigma / on a clear day / with the wind in the right direction sort of qualifiers are attached. Bob > On Feb 26, 2021, at 4:27 PM, John Ackermann N8UR <[email protected]> wrote: > > It's interesting that they talk about the F9 receivers offering 5 ns absolute > time accuracy. Does anyone know of tests confirming that, and what sort of > care was required in the setup to get there? > > John > ---- > > On 2/26/21 9:34 AM, Robert LaJeunesse wrote: >> FWIW. No detailed content, and a rather quick read. "Five key trends in GPS". >> https://www.u-blox.com/en/blogs/insights/five-key-trends-gps >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
