[time-nuts] nuts about position

Mark Spencer mark at alignedsolutions.com
Wed Apr 25 16:30:49 UTC 2018


This link seems to provide an overview of Differential GPS and some related techniques.  

https://www.e-education.psu.edu/geog862/node/1834

Building a system along these lines from "auction site purchases" and home brewed computer code might be a fun project but one would presumably need an accurately surveyed starting point.


Mark Spencer

mark at alignedsolutions.com
604 762 4099

> On Apr 25, 2018, at 8:06 AM, George Watson <watson at sierracmp.com> wrote:
> 
> Create your own DGPS?
> 
> Trimble is good at this.
> 
> George K. Watson
> K0IW
> 
>> On Apr 25, 2018, at 10:56 AM, Tom Van Baak <tvb at LeapSecond.com> wrote:
>> 
>> List -- I had a recent query by a researcher who would like to pinpoint the location of his telescope(s) within 0.3 meters. Also (he must be a true scientist) he wants to do this on-the-cheap. He may have timing requirements as well, but that's another posting.
>> 
>> So I toss the GPS question to the group. Surely some of you have crossed the line from precise time to precise location?
>> 
>> How easy, how cheap, how possible is it to obtain 0.3 m accuracy in 3D position?
>> 
>> When we run our GPSDO in survey mode how accurate a position do we get after an hour, or even 24 or 48 hours? And here I mean accurate, not stable. Have any of you compared that self-reported, self-survey result against an independently measured professional result or known benchmark?
>> 
>> Do you know if cheap ublox 5/6/7/8 series receivers are capable of 1 foot accuracy given enough time?
>> 
>> If not, what improvement would -T models and RINEX-based web-service post-processing provide?
>> 
>> It that's still not close enough to 0.3 m, is one then forced to use more expensive multi-frequency (L1/L2) or multi-band (GPS, GLONASS, Galileo) to achieve this level of precision? If so, how cheaply can one do this? Or is the learning curve more expensive than just hiring an survey specialist to make a one-time cm-level measurement for you?
>> 
>> Something tells me 1 foot accuracy in position is possible and actually easier than 1 ns accuracy in time. I'm hoping some of you can help recommend solution(s) to the researcher's question or shed light on this interesting challenge.
>> 
>> Thanks,
>> /tvb
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at 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 at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 



More information about the Time-nuts_lists.febo.com mailing list