<div dir="ltr">which messages from the base raw binary data are redundant & not needed by rover strictly & hence need not be sent,<div>in other words which messages are necessarily required from the base raw binary data for quality RTK fix when the internet</div><div>speed is slow for transferring data through NTRIP ? How to do it in SNIP while sending serial stream in raw binary data form from base ?</div><div><br></div><div>Regards,</div><div>Dhirendra singh,</div><div>INDIA</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Aug 24, 2017 at 12:30 AM, <span dir="ltr"><<a href="mailto:foss-gps-request@lists.osgeo.org" target="_blank">foss-gps-request@lists.osgeo.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Send FOSS-GPS mailing list submissions to<br>
<a href="mailto:foss-gps@lists.osgeo.org">foss-gps@lists.osgeo.org</a><br>
<br>
To subscribe or unsubscribe via the World Wide Web, visit<br>
<a href="https://lists.osgeo.org/mailman/listinfo/foss-gps" rel="noreferrer" target="_blank">https://lists.osgeo.org/<wbr>mailman/listinfo/foss-gps</a><br>
or, via email, send a message with subject or body 'help' to<br>
<a href="mailto:foss-gps-request@lists.osgeo.org">foss-gps-request@lists.osgeo.<wbr>org</a><br>
<br>
You can reach the person managing the list at<br>
<a href="mailto:foss-gps-owner@lists.osgeo.org">foss-gps-owner@lists.osgeo.org</a><br>
<br>
When replying, please edit your Subject line so it is more specific<br>
than "Re: Contents of FOSS-GPS digest..."<br>
<br>
<br>
Today's Topics:<br>
<br>
1. Re: Post Processing with RTKLIB (DavidKelley@ITSware.net)<br>
2. Re: Post Processing with RTKLIB (RTKPostProcess)<br>
3. Re: Post Processing with RTKLIB (DavidKelley@ITSware.net)<br>
<br>
<br>
------------------------------<wbr>------------------------------<wbr>----------<br>
<br>
Message: 1<br>
Date: Tue, 22 Aug 2017 13:35:42 -0700 (MST)<br>
From: "DavidKelley@ITSware.net" <DavidKelley@ITSware.net><br>
To: <a href="mailto:foss-gps@lists.osgeo.org">foss-gps@lists.osgeo.org</a><br>
Subject: Re: [FOSS-GPS] Post Processing with RTKLIB<br>
Message-ID: <<a href="mailto:1503434142706-7573585.post@n2.nabble.com">1503434142706-7573585.post@<wbr>n2.nabble.com</a>><br>
Content-Type: text/plain; charset=us-ascii<br>
<br>
Post processing raw observation data gathered in the field has been very<br>
common decades and you should have no problems using RTKLIB (the RTKPOST<br>
tool) for that. Many "old timers" still do it that way for various reasons<br>
and when we are in the filed we are checking as we go but we old "trust" the<br>
post processed results. And post processioning means you can also use final<br>
orbits and other data products that are readily available to get better<br>
results. All of this is moot if your field data is itself corrupted. And<br>
you can easily turn RTCM3.x into RINEX files with other RTKLIB tools and<br>
find 3rd party processing services to solve it for you.<br>
<br>
Time synchronization will not in fact be an issue. RTCM 3.x provides the<br>
precise time over the current GPS week, so you have to tell the tool (RTKLIB<br>
or any other such tool) what week a file came from but the file name<br>
conventions used often help with that. There are a few other messages and<br>
tricks, but this solves 99% of your issues. The navigation filter will then<br>
determine the precise time.<br>
<br>
The data from the "nearest RTK" station of course depends on where you are.<br>
Many tools (RTKLIB, SNIP, and often the NTRIP Caster device itself) will<br>
provide a means to capture the raw RTCM data for your post processing needs.<br>
NGS CORS even runs a long term FTP site with such data, but the data is<br>
decimated. Depending on your application that may not be an issue.<br>
<br>
*So yes this is quite possible and routinely done*. But you have not told<br>
the group anything more about the devices in the field (the rovers) and what<br>
span of location and how often the positional estimates are wanted, what<br>
precision is required, etc. Many of the practical details and useful advice<br>
you might get will turn on that. Regards, DCK<br>
<br>
<br>
<br>
--<br>
View this message in context: <a href="http://open-source-gps-related-discussion-and-support.1099874.n2.nabble.com/Post-Processing-with-RTKLIB-tp7573584p7573585.html" rel="noreferrer" target="_blank">http://open-source-gps-<wbr>related-discussion-and-<wbr>support.1099874.n2.nabble.com/<wbr>Post-Processing-with-RTKLIB-<wbr>tp7573584p7573585.html</a><br>
Sent from the Open Source GPS-related discussion and support mailing list archive at Nabble.com.<br>
<br>
<br>
------------------------------<br>
<br>
Message: 2<br>
Date: Tue, 22 Aug 2017 23:42:35 -0700 (MST)<br>
From: RTKPostProcess <<a href="mailto:g.bado@ro-sys.hu">g.bado@ro-sys.hu</a>><br>
To: <a href="mailto:foss-gps@lists.osgeo.org">foss-gps@lists.osgeo.org</a><br>
Subject: Re: [FOSS-GPS] Post Processing with RTKLIB<br>
Message-ID: <<a href="mailto:1503470555485-7573586.post@n2.nabble.com">1503470555485-7573586.post@<wbr>n2.nabble.com</a>><br>
Content-Type: text/plain; charset=us-ascii<br>
<br>
Thank you for your answer,<br>
The device contains an NV08C-CSM GNSS module, with 2JM013-010/113-UFL<br>
antenna. The desired precision is 2cm, and we need them as often as<br>
possible, we want a really precise route from the FIX data.<br>
My problem with the synchronization is that we can capture both the rover<br>
and the base station data, but because we capture it in two different place,<br>
it maybe cause some problem when we want to process it. For example because<br>
of the slow internet connection or anything else the .tag file we create for<br>
this probably will have a few second delay.<br>
<br>
Best regards,<br>
Greg<br>
<br>
<br>
<br>
--<br>
View this message in context: <a href="http://open-source-gps-related-discussion-and-support.1099874.n2.nabble.com/Post-Processing-with-RTKLIB-tp7573584p7573586.html" rel="noreferrer" target="_blank">http://open-source-gps-<wbr>related-discussion-and-<wbr>support.1099874.n2.nabble.com/<wbr>Post-Processing-with-RTKLIB-<wbr>tp7573584p7573586.html</a><br>
Sent from the Open Source GPS-related discussion and support mailing list archive at Nabble.com.<br>
<br>
<br>
------------------------------<br>
<br>
Message: 3<br>
Date: Wed, 23 Aug 2017 03:19:02 -0700 (MST)<br>
From: "DavidKelley@ITSware.net" <DavidKelley@ITSware.net><br>
To: <a href="mailto:foss-gps@lists.osgeo.org">foss-gps@lists.osgeo.org</a><br>
Subject: Re: [FOSS-GPS] Post Processing with RTKLIB<br>
Message-ID: <<a href="mailto:1503483542797-7573587.post@n2.nabble.com">1503483542797-7573587.post@<wbr>n2.nabble.com</a>><br>
Content-Type: text/plain; charset=us-ascii<br>
<br>
In this case you are planning to use low lost L1 only device with a ten<br>
dollar patch antenna. Search for Michele Bavaro to find practical use tips<br>
on that chip and RTKLIB. By now you probably know L1/L2 is to be preferred,<br>
and that you need to be <15km (better yet <10km) from your base stations to<br>
get fixes with this setup. We have done RTK mobile <2cm work on vehicles<br>
with the NV08 and RTKLIB, but we tend to use better antenna (see<br>
<a href="https://www.use-snip.com/kb/knowledge-base/question-what-antenna-should-i-use/" rel="noreferrer" target="_blank">https://www.use-snip.com/kb/<wbr>knowledge-base/question-what-<wbr>antenna-should-i-use/</a>).<br>
You do not state your data rates, only "as often as possible" - to some<br>
people that means 1Hz, to others much more (that chip does 20hz with the<br>
normal increase in measurement noise floor). One presumes you have a<br>
generally clear sky? No forest cover? Is this a drone, a ground vehicle or a<br>
manpack or other? This directly effects the expectations of signal loss you<br>
will have. You will end up with lots of data, in the NV08 propriety format,<br>
that you will then translate to RTCM3 or to RINEX for use in post. And<br>
RTKLIB does all that just fine.<br>
<br>
If you are processing "at the end of the day" then the slow internet should<br>
not matter here (see prior reply about time tags, I do not think you will<br>
need to use the tag option), but perhaps I do not understand your config. It<br>
is likely you will want to record the RTCM streams from all the base<br>
stations your device may be near and select which is best in post. You have<br>
not mentioned what the span of rover operation would be. BTW, a point I<br>
failed to note in my first post of that you need not send a precise / good<br>
position to the NTRIP Caster and you only need to send it once. For most<br>
needs, a 1km will suit, so in fact the unaided fix from this device in<br>
NMEA-183 format will be fine (or you can add it by hand). The Caster will<br>
then pick the best station to send to you (and you will get the exact<br>
location for that data).<br>
<br>
<br>
<br>
--<br>
View this message in context: <a href="http://open-source-gps-related-discussion-and-support.1099874.n2.nabble.com/Post-Processing-with-RTKLIB-tp7573584p7573587.html" rel="noreferrer" target="_blank">http://open-source-gps-<wbr>related-discussion-and-<wbr>support.1099874.n2.nabble.com/<wbr>Post-Processing-with-RTKLIB-<wbr>tp7573584p7573587.html</a><br>
Sent from the Open Source GPS-related discussion and support mailing list archive at Nabble.com.<br>
<br>
<br>
------------------------------<br>
<br>
Subject: Digest Footer<br>
<br>
______________________________<wbr>_________________<br>
FOSS-GPS mailing list<br>
<a href="mailto:FOSS-GPS@lists.osgeo.org">FOSS-GPS@lists.osgeo.org</a><br>
<a href="https://lists.osgeo.org/mailman/listinfo/foss-gps" rel="noreferrer" target="_blank">https://lists.osgeo.org/<wbr>mailman/listinfo/foss-gps</a><br>
<br>
------------------------------<br>
<br>
End of FOSS-GPS Digest, Vol 102, Issue 2<br>
******************************<wbr>**********<br>
</blockquote></div><br></div>