Re: [time-nuts] GPS position averaging

olep...@gmail.com said: > My question is twofold; 1) is this for some reason a bad idea? And 2) How do > I average the numbers? I can not put my finger on it but it "feels wrong" to > average lat, long and height independently. It seems like an interesting idea to me. It would be interesting to

Re: [time-nuts] GPS position averaging

I am new to this list and to this topic, but it seems to me that if one wants to come up with an average of a set of spatial measurements, one would use distance as the parameter to be averaged. The distance would presumably be that from a fixed spatial reference point (0,0,0). One would then t

Re: [time-nuts] GPS position averaging

I would recommend determining your terrain's elevation using a topo map and estimating or measuring antennas height above ground. And then excluding survey results with wacko altitudes before averaging. While we often set the elevation angle mask high for timing purposes, for survey purposes espec

Re: [time-nuts] GPS position averaging

The Ublox M8N can send out raw measurements with messages TRK-MEAS and TRK-SFRBX for observation and navigation data: you can postprocess them to improve the accuracy. On Mon, Dec 15, 2014 at 12:43 PM, Tim Shoppa wrote: > I would recommend determining yo

Re: [time-nuts] GPS position averaging

On Mon, Dec 15, 2014 at 10:52 AM, Azelio Boriani wrote: > The Ublox M8N can send out raw measurements with messages TRK-MEAS and > TRK-SFRBX for observation and navigation data: you can postprocess > them to improve the accuracy. > And searching the archives for rtklib should find some relevant

Re: [time-nuts] GPS position averaging

Hi Simple answer - there is no simple answer. You will get significantly better results by intelligently processing the data than by a giant “average everything in sight” approach. Also consider that various GPS modules seem to have offsets in their nav solution. The NIST papers on various GP

Re: [time-nuts] GPS position averaging

On Mon, 15 Dec 2014 17:55:20 -0500, you wrote: >Hi > >Simple answer - there is no simple answer. > >You will get significantly better results by intelligently processing the data >than by a giant “average everything in sight” approach. > >Also consider that various GPS modules seem to have offse

Re: [time-nuts] GPS position averaging

Hi > On Dec 15, 2014, at 6:39 PM, Angus wrote: > > On Mon, 15 Dec 2014 17:55:20 -0500, you wrote: > >> Hi >> >> Simple answer - there is no simple answer. >> >> You will get significantly better results by intelligently processing the >> data than by a giant “average everything in sight” app

Re: [time-nuts] GPS position averaging

This may be one of those cases where the human brain's ability to see patterns would help to see the distribution and eliminate outliers. Plot a manageable set of X and Y points, and another set of X and Z points. To make the three dimensions plot as one in a statistical distribution (bell) curve

Re: [time-nuts] GPS position averaging

Hi > On Dec 15, 2014, at 7:19 PM, Bill Hawkins wrote: > > This may be one of those cases where the human brain's ability to see > patterns would help to see the distribution and eliminate outliers. Plot > a manageable set of X and Y points, and another set of X and Z points. yup > > To make

Re: [time-nuts] GPS position averaging

Hi Actually there may be a Time Nuts relevant reason for wanting to know the true / correct / survey location. If your desire is to know UTC to ns or something like that, an indicated position error *probably* relates directly to a time error. Being able to correct the position error may allo

Re: [time-nuts] GPS position averaging

kb...@n1k.org said: > The problem shows up when the GPS constellation is in a configuration that > accentuates the error. That’s often a 12 / 24 / 48 hour sort of thing. It would be interesting to compare the results from daytime vs nighttime, or today vs yesterday. -- These are my opinions

Re: [time-nuts] GPS position averaging

Hi > On Dec 15, 2014, at 8:07 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> The problem shows up when the GPS constellation is in a configuration that >> accentuates the error. That’s often a 12 / 24 / 48 hour sort of thing. > > It would be interesting to compare the results from daytime

Re: [time-nuts] GPS position averaging

On Mon, Dec 15, 2014 at 6:39 PM, Angus wrote: > But is it the closest to the 'true' position that you really want, or > the best estimate of where the particular GPS you are testing thinks > it is? > I don't understand what you're saying here. Can you phrase it differently?

Re: [time-nuts] GPS position averaging

Hi > On Dec 15, 2014, at 8:29 PM, Paul wrote: > > On Mon, Dec 15, 2014 at 6:39 PM, Angus wrote: > >> But is it the closest to the 'true' position that you really want, or >> the best estimate of where the particular GPS you are testing thinks >> it is? >> > > I don't understand what you're s

Re: [time-nuts] GPS position averaging

On 12/15/14, 5:35 PM, Bob Camp wrote: Hi On Dec 15, 2014, at 8:29 PM, Paul wrote: On Mon, Dec 15, 2014 at 6:39 PM, Angus wrote: But is it the closest to the 'true' position that you really want, or the best estimate of where the particular GPS you are testing thinks it is? I don't under

Re: [time-nuts] GPS position averaging

On Mon, Dec 15, 2014 at 8:35 PM, Bob Camp wrote: > So the question - If they are not going to be equal, which one do you pick? The better one. If the math is sound the presumably the better position results in better time. If there are correlated defects then I suppose the GPS provided solutio

Re: [time-nuts] GPS position averaging

On Mon, Dec 15, 2014 at 9:01 PM, Jim Lux wrote: > if you've got observables and they're in RINEX format, you can do offline > processing through JPL's GIPSY thing.. According to the upload form APPS still requires dual frequency. The underlying Gipsy system may not have that constraint but I o

Re: [time-nuts] GPS position averaging

On 12/15/14, 6:46 PM, Paul wrote: On Mon, Dec 15, 2014 at 9:01 PM, Jim Lux wrote: if you've got observables and they're in RINEX format, you can do offline processing through JPL's GIPSY thing.. According to the upload form APPS still requires dual frequency. The underlying Gipsy system ma

Re: [time-nuts] GPS position averaging

I compared results from many different timing receiver surveys (VP, UT+,Resolution-T,SMT, Jupiter , that of LH for my T-Bolt, Ublox-6T) with the Google Earth position and with the exception of the Ublox receiver they are all within the bounds of the GE uncertainty which is around 2m from the re

Re: [time-nuts] GPS position averaging

Hi > On Dec 15, 2014, at 9:39 PM, Paul wrote: > > On Mon, Dec 15, 2014 at 8:35 PM, Bob Camp wrote: > >> So the question - If they are not going to be equal, which one do you pick? > > > The better one. If the math is sound the presumably the better position > results in better time. > If th

Re: [time-nuts] GPS position averaging software?

John, I use WinOncore12, it's written by motorola, but no longer supported by them. You can get the install file from here http://www.jackson-labs.com/support.html On 2011-04-13 11:44, John Ackermann N8UR wrote: Just got a pair of GPS antennas on the roof and I'm interested in both getting a

Re: [time-nuts] GPS position averaging software?

John, Visual GPS (http://visualgps.net/) will do this for you. RTKLIB may also be of interest (http://gpspp.sakura.ne.jp/rtklib/). -Kevin - Original Message - From: "John Ackermann N8UR" To: "Discussion of precise time and frequency measurement" Sent: Tuesday, April 12, 2011 6:44

Re: [time-nuts] GPS position averaging software?

John, try out the u-Blox Control Center at www.ublox.com. Primarily writte for their suite of GPS units, but works just fine with any NMEA enabled receiver. 73s Achim, DH2VA ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to http

Re: [time-nuts] GPS position averaging software?

John, Visual GPS (http://visualgps.net/) will do this for you. [] -Kevin Seconded. It works with Garmin GPS 12 XL and GPS 60 CSx, and likely many others. Very nice position performance plot with both mean and least squares averages. I've just tried the u-Blox Control Center which Achim

Re: [time-nuts] GPS position averaging software?

I did this with our newly installed Thunderbolt. When I plugged the coordinates into Google Earth, the center of the image was dead on with the skylight where the antenna is. Not just pointing at the skylight, but the correct part of the skylight. Could be coincidence, but I'd say the error

Re: [time-nuts] GPS position averaging software?

) and linger on scene to do averaging. It is the USGS NAIS database IIRC. --Original Message-- From: David VanHorn Sender: time-nuts-boun...@febo.com To: Discussion of precise time and frequency measurement ReplyTo: Discussion of precise time and frequency measurement Subject: Re:

Re: [time-nuts] GPS position averaging software?

True, but my setup isn't very portable. I'm happy, I'm getting my 10.00 MHz output and it's WAY more accurate than I need. The rest is delicious bacon gravy! ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.c

Re: [time-nuts] GPS position averaging software?

The Motorola software ("Winoncore", Google will find it at www.synergy-gps.com) has a feature that plots position average, actually two "averages" it give s a running "mean" and a running "least squares" and plots both on Lat Long. My Oncore GPS is connected to a LInux based server but I run the

Re: [time-nuts] GPS position averaging software?

Thanks, all, for the suggestions. I'm playing with WinOncore12 at the moment -- for some reason I'm not able to get the M12+ receiver into NMEA mode so VisualGPS isn't usable. I'll fuss more with NMEA mode this weekend, but is there any magic for the ioformat switch? I've used the command fr

Re: [time-nuts] GPS position averaging software?

Hello John, If your M12+ is a Timing model, then there is no NMEA mode... HTH, Regards, Jean-Louis - Original Message - From: "John Ackermann N8UR" To: "Discussion of precise time and frequency measurement" Sent: Thursday, April 14, 2011 3:35 PM Subject: Re: [tim

Re: [time-nuts] GPS position averaging software?

is no NMEA mode... HTH, Regards, Jean-Louis - Original Message - From: "John Ackermann N8UR" To: "Discussion of precise time and frequency measurement" Sent: Thursday, April 14, 2011 3:35 PM Subject: Re: [time-nuts] GPS position averaging software? Thanks, all, for