In message <[EMAIL PROTECTED]>, Hal Murr ay writes: > >> Position hold mode allows them to solve N(sat) equations with one >> unknown instead of N(sat) equations with four unknowns. > >That assumes you have good data for your location. > >How good is the find-my-location code?
It averages 10000 position samples and that is appearantly good enough. I played with plotting the per satelite residuals as a function of a deliberately distorted set of coords for position hold and it is quite insentitive. The main effect of a slightly off position seems to be a diurnal component to the estimated uncertainty more than an actual component to the PPS output. If you record the per sat residuals along with long+lat for the sats and average the residual per az/elev gridpoint for a day or two, you will be able to see a systematic effect but translating this into a tangible delta to the held coordinates has so far escaped me. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
