Accuracy issues

Hi, I have a reach rx (rover) taking correction from a rs2+ (base) bia LTE, set on a known precise point. The issue I’m having is that sometimes when I go to stake out a control point nearby or any point, it will be off about 2 inches horizontally. sometimes it will be on point and sometimes it will be off. how can I correct this?


Hi @ajexgood,

RX provides cm-level accuracy. It can be higher or lower depending on various factors such as conditions and baseline. Please make sure that there are no obstructions near your survey site and that your baseline is within 60km.

If you get different coordinates when staking out in the same setup and location, please send us the known coordinates and a file with 2 collected positions from Flow so that we can investigate the difference. You can send this to

Were the base coordinates the same in different tests? The accuracy of the rover depends on the accuracy of the base position.

Please check if you’re using the latest version of the Emlid Flow and the latest Reach firmware.

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Hi, what type of file do you need from Flow? Is a project file all right?

Yes, you can export your project with mismatching coordinates in CSV format and send it to

I have the same problem, but using the RX autonomously. How can I trust this equipment with 50cm differences in a FIX solution? Is the poor precision and accuracy only in the RX or also in the RS2+ and RS3?

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Hi Sara,

There are several factors that can affect the accuracy of the solution, and we’d like to look at and investigate such cases individually. Since I know you’re in contact with us via email regarding this issue, I suggest we continue there to avoid any confusion.

If anyone has similar issues, please reach out to us at, and we will take a look.

Using the receiver “autonomously” (without corrections) you will only obtain meter accuracy at best.

Using a correction source, i.e. Lora (radio) from a base station on a known or unknown point or by ntrip broadcasts you will obtain centimeter accuracy.