M2 measurement point

Hi all,

We plan to purchase an M2 for UAV positioning via PPK.

Can someone please enlighten me: will the calculated position correspond to M2’s position, or to the antenna centre’s position?

Background / further questions: This is a lack of understanding on my side with GNSS in general. For RS+ and RS2 that we use regularly, it is easy, because the receiver and the antenna are one. For M2 they are separate. How do I deal with lever arms between the receiver and the antenna? Assuming the antenna is fixed in space and the receiver is moving around a lot, will the position be fixed or not? What is the roles were swapped?

Many thanks in advance,

If there’s an antenna it’s always the antenna. (Not a LoRa radio antenna) I don’t know exactly where the phase center is for the helical antenna Emlid sells but the majority of them I have seen have been about 2/3rds the way up the antenna. There is usually a 2-3mm difference between the L1 and L2 bands with the L2 normally being higher. A similar antenna I have for the Yuneec H520E RTK says 29 and 32mm from the base of the antenna respectively so we use 30.5mm.


Reach M2 GNSS antenna phase centers’ offsets for L1 and L2 are 0.035 m and 0.037 m respectively.

1 Like

0.035m is 35mm or 0.184 bananas. Just for the non-metrics.

Sorry, been on too much Reddit lately. :slight_smile:


Hi Marcel,

Welcome back to the forum!

I have nothing to add to the posts here :wink: Our users have already explained that the main thing is the antenna’s position. It’s the antenna that actually receives the satellite data. So it’s its position you’re getting.

To tell you the truth, my mind doesn’t wrap around the idea of a fixed antenna and a moving receiver. Still, if that were going to happen, you would get a fixed position as your antenna is not moving.

Our helical antenna’s offsets are indeed 0.035 m and 0.037 m for L1 and L2 respectively. They are mentioned in our docs.

1 Like

Michael, I guess there’s no such thing as too much Reddit :laughing:

1 Like

Are you using Datapilot for the H520E?

Yes. Version 2.0. I don’t recall if the update service is pushing it yet.


This topic was automatically closed 100 days after the last reply. New replies are no longer allowed.