Hi Brooke, Thank you for your suggestions, that page is probably ripe for a rewrite, but I may just add a link to your page for now :-)
I would have thought the GPS receiver averages the readings when it locks on multiple satellites. Are you saying it only uses one at a time? If so, what's the point of a self survey? I talk about WWV because most ham operators have a receiver that receives WWV, so it is an inexpensive and convenient way to get an absolute reference, even though it is not as good as GPS. I am sure there is a reason why timing receivers track all the way down, instead of switching to a better bird when one is available, but by setting the mask angle fairly high (appropriate for your location and obstructions), you can take care of this problem. Didier KO4BB > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Brooke Clarke > Sent: Friday, December 14, 2007 2:16 PM > To: time-nuts@febo.com > Subject: [time-nuts] Time Transfer > > Hi Didier: > > Been surfing your Timing web page and came across > http://www.ko4bb.com/Timing/FrequencyReference.html > Got there by working up the URL for the Vig paper. > > An ordered list of Time Transfer methods from carrier phase > GPS to the Astrolabe is at: http://www.prc68.com/I/timefreq.shtml#TT > that ranks HF time stations far below other methods, so > although they can be used there may be better choices that > are affordable. > > Also for GPS timing applications (i.e. the GPS receiver is in > position hold > mode) a single satellite is all that's needed. Adding more > satellites can add a failure alarm function but may not > improve accuracy. In my case multipath is a big problem so a > high elevation mask is needed. > > The problem with a less than 12 channel receiver relates to > how satellites are selected. The Motorola timing receivers > will continue to track a satellite until it sets rather than > switch to a a new one which may be directly overhead. > The "use highest in the sky" applies to how a new satellite > is selected. > Once selected the satellite is tracked until it sets. > > An idea: When averaging GPS 1 PPS signals the receiver > switches satellites as the currently tracked ones set so > there may be a slight change in accuracy because of the > satellites being used. But changing from a satellite that's > about to set i.e. that has a lot of multipath to high in the > sky sat should make for a better 1 PPS. > > -- > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.precisionclock.com > http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.