Same height measurements with ESRI

Hallo,
ok, understood. Still it makes more questions …
We use EMLID, NTrip (to put data in GPS mock location) and ESRI - apps, on Nokia 4.2 android phone

  1. I added directly in ESRI App (with data from RS2, thru NTRIP, …) point: trees. And these were “planted” on soil level, not 100m above.

  2. I added directly lines: (golf stuff: hazard, bunker,…) also on soil level

  3. I took x/y data to add trees indirectly in ESRI online -> also planted on soil level.

Hmmm, I would expect a difference reading last posts conclusion.
Maybe for your further analysis.
Best Christian

Hi Christian,

can I just double-check I understood correctly, you’ve got the same height for all points regardless of where you took them?

Cheers,

Markus

Hallo Markus,
Yes.
Which should not be, …
(unless ESRI would ignore “height” and put all down to soil level).

:slight_smile: No flying trees, :slight_smile:

Best Chris

Could you export the points via CSV file and check if they are ok at that stage, I mean before they go into ESRI. Reach View 3 would probably be the easiest app to use, just to check the system is getting the correct height before checking details of the apps you’re using.

Hallo,

not not reach view3.
My conifg is:

  1. RS2 with rtk, sapos nrw input
  2. NTRIP from lefebure also with rtk, sapos nrw
  3. into the gps mock locations @ android / nokia 4.2
  4. ESRI collector takes “telephone gps position” which is the rtk corrected
    4.1 lines, points, … in ESRI

I do not take any file in between, no data transfer

clearer?
Best Chris

Hi Chris,

I never worked with ESRI, so I am not sure how to solve this. But if you’re after the correct heights I’ve just posted a workaround here that you can use in the meantime. But you would have to use reach view 3 or any other survey app that can export CSV files to use in Excel.

Cheers,

Markus

Hi Christian,

In which coordinate system does your NTRIP provider send the corrections? I suppose it should be ETRS89 or something like that?

What coordinate system did you set in ESRI Collector?

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Hallo Svetlana,

Georeferenzierung: RTK service SAPOS - NRW - DE (see link here under)

Lage / Lageangabe: Kartesische Koordinaten XYZ im ETRS89/DREF91 in der Realisierung 2016
Höhe / Höhenangabe:
    Ellipsoidische Höhe bezogen auf GRS80
    NHN-Höhe bezogen auf DHHN2016 (Höhenstatus 170) bei Nutzung des GCG16

from : https://www.bezreg-koeln.nrw.de/brk_internet/geobasis/raumbezug/sapos/heps/index.html

ESRI Collector
… hmm ? cant find the refsystem in ESRI collector.

I checked:

  • Reach View; direct: height :123m -> wrong
  • NTRIP lefebure; postprocessing: height 78m -> ok
    (I have screenshots, if you mind)

Thats an answer which helps?

Best Chris
sorry for late answer… business during the week :slight_smile:

Hi Christian,

As far as I can see, your NTRIP caster has two option for heights:

  • Ellipsoidal height based on GRS80

  • Orthometric height based on DHHN2016

What option did you choose?

Reach requires ellipsoidal heights to operate correctly.

Hey Svetlana,
I did not chose anything… :slight_smile:
But it uses the DHHN2016
Best Chris

Hi Christian,

I guess that’s the root of the issue. To work correctly, Reach requires ellipsoidal heights coming from NTRIP. As far as I understand how NTRIP casters work, they should have a mount point, which transmits ellipsoidal heights. I’d suggest contacting your provider to check if they have one.

Hallo


https://gppspro.saposnrw.de/term.php
-> Referenzstationen & VRS, MAC, FKP

in the end they have the latest (see wiki) DHHN2016 in .

Best Chris

Related to your issue:

Source material describing this:

Der amtliche Höhenbezugsrahmen DHHN2016 (Höhenstatus 170) wird im SAPOS® über RTCM 3 als DE_DHHN2016_NH übermitt elt. Die dafür notwendigen Transformationsinformationen („Coordinate Transformation Mess ages“ ) sind in den speziell dafür vorgesehenen Botschaften 1021 und 1023 des RTCM integriert und werden kostenlos abgegeben. Sofern der Rover diese Transformationsbotschaften 1021 und 1023 verarbeiten ka nn, ist eine Auswertung nach Aktivierung im Rover möglich . Die „Coordi nate Transformation Messa ges“ des SAPOS® NRW basieren auf dem bundesweiten AdV-Quasigeoid GCG2016, das für NRW Undulationswerte mit einer durchschnittlichen Genauigke it von 1 cm liefert. Gebrauch shöhen im DHHN2016 im Höhenstatus 170 können mitt els GNSS-HEPS-Mess ungen über SAPOS®mit einer Gesa mtgenauigke it von bestenfalls2 bis 3 cm (SAPOS®-Höhengenauigke it und -Modellgenauigke it) bestimmt werden.

As far as I know, these messages cannot be read by Emlid currently. Vertical heights output by Reach are thus ellipsoidal heights and you need to specify a transformation to orthometric in your target software.

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Hi Chris,

At the moment, to operate correctly, Reach requires ellipsoidal heights and geographic coordinates from the base. On the rover, you can collect points in the local coordinate system.

DHHN2016 vertical datum provides orthometric heights. That’s why you have the wrong coordinates on the rover.

I’d suggest checking with SAPOS if they can provide ellipsoidal heights.

Also, Gabriel shared the info about RTCM3 height transformation messages. For now, we’re investigating how we can support them.

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As said, when it runs, I have no problems using Reach, Lefebure and internal Mock up positions. These are correct also in height (Gütersloh is at 79m …)

Best Chris

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Hi Chris,

Do you mean it works correctly with ESRI Collector now?

Hallo Svetlana,

It always did. My point from the beginning was, that the combination of Reach RS2 with Ntrip and Lefebure gives the right results out of Lefebure (into Android mock positions).

THis is a work around. INteresting for all those that find “data point collection” in Reach view not practically enough. And or need the input in other tools: openstreetmap, … ESRI , … whatsoever…
Best CHris

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Hi Christian,

We’re constantly working on improving ReachView in general and the Survey tool particularly. So, your feedback is a great help for us! If you have a request for some specific features, don’t hesitate to post them.

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