Emlid Ntrip horizontal 32-35 cm difference according to Turkey's goventment Ntrip Service

Hi I have 2 rs2 and ı setup 1 base 1 rover on emlid caster. İn base station setup I configure the base mode 1006 arp 0.1 hz, 1074 gps 1hz, 1084 glonass 1hz, 1094 galileo hz, 1124 beidou 1hz , 1230 glonass code- phase biases 2 hz and gnss update rate 5hz, my rover update rate is 10 hz I have fix solution in emlid caster but when I control my countries ntrip caster 20-35 cm diffference
in 1 km baseline emlid caster- my countires Ntrip caster(TUSAGA) have you an any opinion what is this reason?

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There are my training survey to day.

I collect these (up and down in photos) points my countries Ntrip service( TUSAGA) and ı stake out the points Emlid caster.

To day İn base station setup I configure the bases rtcm messages 1006 arp 0.1 hz, 1004 gps 1hz, 1012 glonass 1hz, 1094 galileo hz, 1124 beidou 1hz and gnss update rate 1hz and broadcast my coordinates to emlid caster. I start survey with my Rover. İn 5 km baseline my horizontal and vertical difference according to the government ntrip broadcast in my country 3 cm but after 10 km horizontal accuracy is rised to 32-35 cm. How must ı configer the base and Rover rtcm messages and their rates to eleminate this fault ? Someone help me please.

Couple things i see that may not solve your problem, but may help otherwise.

Use default settings:
Elevation Mask 15
SNR Mask 35
Update Rate 5Hz

Can you try another CORS station / countries NTRIP Caster nearby to compare in case issues with particular station?

Thank you for your reply Tim. I tryed a couple of variaties combination of mask Angeles rates hz but I can’t find anybstable combination of them.In the beginning, it was around 5 cm up to 900 metres. After 900 meters the difference increased to 30-35 cm. By trying, I was able to reduce it to 3 cm in 5km, but I still don’t trust its stability, I constantly check it. I’m hoping I can find a combination that works for me.

There have been discussions over the years. You can try searching also if nobody jumps in right away. The issue usually stems from the ntrip cors station, not the Emlid receivers.

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Hopefully you are in contact with your NTRIP provider for help also as they may have an answer. Your settings may be fine as getting a FIX.

The only ntrip broadcaster in my country is the government’s TUSAGA system. Currently, I can receive stable solutions from the TUSAGA system. I also utilize this system when determining the coordinates of the base station. I don’t understand why a system that can travel 60 km on paper is causing such errors at such short distances. I must have missed something.

Hi Mehmet,

Welcome to the community!

To help us investigate, could you provide the following information:

  • How is the base position set? Are you using a permanent survey marker, averaging, or PPP?

  • Is the NTRIP service and base positioning set to the same datum?

Could you also send the CSV files of the measurements, both from the base and the TUSAGA NTRIP? Additionally, have you tested it with a benchmark?


Thank you Merryna. I am very happy to join the community. I have set my base station at an average fixed solution with TUSAGA broadcasting. The datum used in my region is turef tm33. However, coordinates cannot be entered from this datum in the fixed setup. Coordinates in the WGS84 datum are automatically entered by the software. I have been collecting points with TUSAGA for 2 weeks and making the stake out with emlid broadcast. I still have not achieved a stable result.Since I haven’t collected points from both broadcasts, I am unable to send the CSV file at the moment, but I will collect points both broadcasting and get back to you tomorrow during my first available free time.

As far as I have researched, TUSAGA-Active system Network-RTK Correction Data is broadcasting in the GRS80 ellipsoid ITRF96 datum 2005.00 reference epoch. Could there be a deviation between Wgs84-itrf96 because I took its fixed position from the average fix?

Maybe I should determine the coordinates of the base station by static measurement.

Today, I opened a job in Emlid Flow and defined the coordinate system of my region as Turef TM33. Since the ntrip broadcast in my region also broadcasts at this datum, I was able to plot my control points with an accuracy of 2-3 cm. As far as I understand, since the corrections I sent to the emlid caster publication are in the WGS84 coordinate system and my project is derivative tm33, I get these differences (according to the 32-35 cm to tusaga publication). Isn’t there a way to determine my base station in my own coordinate system, that is, to broadcast from emlid caster to in turef tm33 coordinate system ?

Hi Mehmet,

When you determine your base position, it won’t automatically be set to WGS84. For instance, if you average fix your base using TUSAGA NTRIP, your base position will be in the datum of that NTRIP correction. Similarly, if you determine your base using a permanent survey mark (PSM), your base position will be in the datum of that PSM.

If I understand correctly now, you already have 2-3 cm accuracy using NTRIP correction in Turef TM33. Do you want to set up the base with this datum? You can averaging fix with that NTRIP correction and set the project on the same datum and projection.

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Yes, you understood correctly. With Turef tm33 correction (tusaga active Ntrip broadcasting) I can determine its position with an accuracy of 2-3 cm because broadcasting and mynproject coodinates are same. However, even if I select the setup the coordinates from the project to the wgs84 system, as seen in the photo, it is automatically converted. What I want to know is the solution I published via Emlid Caster in the wgs84 system. If this is the case, Ntrip broadcast and the project are not in the same system, as seen as a warning in emlid flow. In other words, the corrections I published via emlid caster are in the wgs84 system and the coordinate system I use in my region is Turef TM33.

Uploading: 20240601_122838.jpg…

ev sabit deneme.zip (1.8 KB)
There is the csv file.

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[quote]mehmetaliyuceltr, post:6, topic:38561, full:true
bases rtcm messages 1006 arp 0.1 hz,…
…configer the base and Rover rtcm messages and their rates[/quote]

Use Ntrip Checker, and see what messages they are sending

NtripChecker - Apps on Google Play
Ntrip checker on the App Store

If behind a router, the Port number used may have to be opened. In US, using Verizon via 7730L MiFi, I had to allow the port number to pass thru.

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