From: "Poul-Henning Kamp" <[EMAIL PROTECTED]> Subject: Re: [time-nuts] Positional accuracy of the M12+T Date: Wed, 03 Jan 2007 19:26:02 +0000 Message-ID: <[EMAIL PROTECTED]>
> In message <[EMAIL PROTECTED]>, " > Randy Warner" writes: > > >You will see several > >ns of 1PPS offset due to slight changes in the Position Hold Position, > >but this is easily removed using the 1PPS offset commands if you are > >trying to match to another receiver. > > Are you sure these offsets are constant ? My impression is that they > depend on the satellite geometry ? Having looked at the way my position moves around during the day (the surveying mode in the M12M-T windows software plots it live as it goes along) I am fully convinced that it does move around due to geometry. A position error cranks out as a different time error in the pseudorange depending on the bearing. Toss on the multipath (which is my main error - got to move the antenna). You need to look on the quality of the survey to determin if you need a longer survey period. You need to measure for at least a certain period to be able to be sure that the quality you requested it valid (confidence range is narrow enought), but you should really maintain the averaging until you have reached your surveying goal. Cheers, Magnus _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
