Issue with rs2 offset

[beatrice.pinna95 (Beatrice Pinna)]

Hi,

I’m having an issue with my Emlid RS2 when collecting manual points with Reach View 3.

In particular, when I set the ‘pole height’ on the app, the ‘antenna offset’ is automatically added in order to obtain the correct ‘antenna height’. For example:

Pole = 2 m, Antenna offset for RS2 = 0.134m, Antenna height = 2.134m.

Is this correct?

Similarly, in case of PPK, I set the pole height in Emlid Studio in the Post Processing settings, and the antenna offset is automatically added as a function of the Antenna model used (RS2).

We compared the quota of some points, collected using both methods but we note that they differ exactly 0.134 m. I mean: it seems like we apply twice the 0,134m offset of the antenna on the height values, but we didn’t.

I post two graphs that maybe can help you better understand the problem:

In the first one, you can see the cloud of points collected with PPK, and some points distributed along a diagonal line above the red one are the points collected manually.

Instead, as you can see in the second one, we removed the 0.134 offset from the manual collected points and we obtained a better distribution of the points.

We can’t understand where our mistake is. I hope you can help us handle this.

I’m sorry for the long message

Waiting for a kind reply I thank you all in advance,

Beatrice

[julia.shestakova]

Hi Beatrice,

Nice to see you on the community forum!

We are already in touch with you via email, but I’ll post some updates here to keep everyone in the loop.

@beatrice.pinna95

In particular, when I set the ‘pole height’ on the app, the ‘antenna offset’ is automatically added in order to obtain the correct ‘antenna height’. For example:

Pole = 2 m, Antenna offset for RS2 = 0.134m, Antenna height = 2.134m.

Is this correct?

Yep, antenna height = pole height + antenna offset. Antenna offset is the height from the bottom of the receiver to the antenna phase center. It’s a known value and applied automatically. Here is a small article where you can read more about it.

@beatrice.pinna95

We compared the quota of some points, collected using both methods but we note that they differ exactly 0.134 m. I mean: it seems like we apply twice the 0,134m offset of the antenna on the height values, but we didn’t.

We’ve received the logs from you. Give me some time to check it, and I’ll get back with my thoughts on it.

[julia.shestakova]

Beatrice,

I’ve checked the files from you. For now, we don’t have separate points for comparison, so I can check the LLH log and POS file from PPK only.

As I see, the position log from RTK has just 13.5% of Fix. Mostly it’s in Float, which is sub-meter accurate. It may explain the difference in results.

To understand if there is a mismatch, let’s re-record the logs. But in this case, please also collect several points in RTK just during the logging. It’ll help us process the files in Stop & Go mode in Emlid Studio and compare the results.

Also, do you have the points with known coordinates for comparison? Probably some benchmarks nearby. If yes, please do the new test precisely on them. It’ll give us reference values for analyzing.

[julia.shestakova]

Hi Beatrice,

Curious to know how it’s going! Did you have any chance to do a new test?