Wow. Okay. The user manual actual considers this cable delay to be worth mention?
I can see why the trimble thunderbolt is a favorite among time nuts <3 I'm sold. On 8/21/2012 12:48 PM, Chris Albertson wrote: > On Tue, Aug 21, 2012 at 9:35 AM, Sarah White <kuze...@gmail.com> wrote: > >> Thanks Chris. >> >> I always appreciate clear explanations. I'm assuming that the "fixed >> location" requirement is important to note for purposes of compensating >> for any dopler shift, as well as the distance the signal must first >> travel before being decoded. >> >> ... I would presume that the fixed location used for above calculations >> would be relative to the position of the antenna? I read somewhere that >> even compensating for the length of the antenna cabling is important? >> >> Yes, the GPS' site survey measure the antenna location. And it will not > be exactly right unless you measure the cable length. > > Yes. the cable length delay is close to the speed of light or aboutone > nanosecond per foot. Actually there is a correction called "velocity > factor" that a given cable will have. All this is in the Trimble user > manual and I'm sure the UMs for other GPSes. There is delay in the serial > cable and in any "glue" logic chps and in the PPS distibution amp. To > push the state of the art you have to carefully model all of this. For > normal use you may not have to except if you have really long cables. > > > > Chris Albertson > Redondo Beach, California > _______________________________________________ > 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.