Static report vs emlid caster

Emlid NTRIP Caster Getting started
1

Good day,
I created a Ground control point, did a static report for it and also I connected to caster.emlid.com and used a mount point there but my results differ in approximately 7 decimeter. how is that?

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Emlid Caster is not like CORS, where there are bases spread over a certain region.

In Emlid Caster you need to have your own base and rover setup, where your base messages are sent via the NTRIP protocol and your rovers can receive corrections. If you didn’t use your own base, you might have connected to someone else’s base.

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Hi Linus,

Your rover seems not to receive corrections. That’s why it can’t calculate the coordinates with high accuracy.

Pedro is right. Emlid Caster can pass corrections between your receivers only. You can check this short video on our YouTube channel about the Emlid Caster.

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Good day Pedro,

I USED MY TWO DEVICES, ONE AS A BASE AND THE OTHER AS A ROVER, THEN I CREATED A POINT. USING THAT SAME POINT I DID PPP USING NRCAN BUT MY RESULTS AND NOT THE SAME STILL.

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How did you set your base up? On a known point? If so, what is the datum for the known point coordinates? How long did you observe for PPP? How good was the solution from the PPP report? What datum did you use for PPP output, ITRF or NAD83? The difference could come from the mismatch between datums from PPP and your benchamark source.

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I created a new point and observed it for 4.5 hours in WGS 84.
I selected ITRF and my results was to 14mm semi major, from that report

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Where does the 70cm difference come from? What is the reference you are comparing to?

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Good day,
I created a Ground control point, did a static report for it and also I connected to caster.emlid.com , my comparison is between a static report and that from the emlid caster.

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Or should i used the coordinates obtained from the static report and input it manually.

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Just making sure that everything is correctly understood:

  • Emlid caster is just a relay between your base and your rover (like LoRa)
  • You can connect your rover to a random mount point, but then you should see a very large baseline value - the correction will be worthless if the baseline is too long
  • To use Emlid caster properly, you need to set your base on a precisely known location, like a permanent marker from a geodetic network, connect it to the caster, and use its mount point in your rover

That’s why I am asking about your reference. If you are using two receivers and you are using your rover over the point that you processed through PPP, where is your base? How did you get the position it is sitting on?

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My precise known point is from a static report, i did two one for my base one for my rover.

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Could you look in the CSV export for the point from your caster RTK survey and get the base position and baseline length?

I’m curious to see if it’s what you expect.

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yes i get the base position and the base lenght

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Then I don’t know what is going on. As long as you entered manually the results you got from PPP into your base and your rover is properly connected to it through the caster, 70cm is a lot larger than I’d expect.

There has to be another issue.

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thanks Gabriel

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How to proceed:

BASE RECEIVER:

  • Go to Base mode, select Configure, Manual option and enter the LATLON coordinates in decimal degrees and the ellipsoidal altitude. Set the height of your receiver correctly.

  • Go back to the settings screen, select the Corrections Output option. Choose NTRIP and set the base Emlid Caster settings.

  • Base configuration completed. If you need raw data, go to Logging and start the Raw data option.

ROVER RECEIVER:

  • Go to Input corrections option.

  • Choose NTRIP and input information to Emlid caster’s rover.

If everything works out, your rover will be FLOAT or FIX and using the adjusted base coordinates.

Within Emlid Caster, NEVER choose a base other than your own. You don’t know how it was set up and what precision criteria were used for its placement.

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Hi Linus,

How did you set up the base when you connected to the Emlid Caster? Did you place the base on a known point and enter the coordinates manually, or did you get the base coordinates in Average single?

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