Convert WGS84 height to Ordnance Datum

[JingRan1]

Hello all,

I have a DEM referenced to the WGS84/EGM96 geoid. I want to convert the height value of DEM into the height referenced to Ordnance Datum Malin Head 1965. Is it possible to do it in ArcGIS? Does anyone have idea of how to do it? Thank you very very much.

Best regards,

Jing

[SepheFox]

Melita Kennedy​

[MelitaKennedy]

We aren't doing vertical transformations yet. If the DEM is small enough, you may be able to calculate an overall offset using online geoid model converters. The UK one is OSGM02, online converter is here. If you have elevation heights (not heights above the ellipsoid), you may have to convert them back to ellipsoidal heights using the EGM96 model, then use OSGM02.

Melita

[NeilAyres]

Melita,

this is one question that the surveyors are always beating me on the head about...

Can't do height transformations. Hah!

We have a bunch of vertical datums with-in the system, but then do nothing with them. If you reproject from UTMXX with vertical datum Y to the same UTM with vertical datum Z, nothing happens.

Has been an issue for a while now. Say, many years.

Even going from WGS84 geoidal to ellipsoid is not something that can be easily achieved.

So, in amid all this development of online wizzy stuff, is anyone actually thinking about these mapping basics?

[MelitaKennedy]

Yes.

Oh, you wanted more?  

Actively being worked on for next release in that other teams have either done some work or are discussing what to do. How much functionality will be there? I'm not sure yet, and can't give any details or my managers will be after me.

Melita

[NeilAyres]

Thanks Melita,

just upgrading to 10.3.1 today.

Lets hope I don't have to wait for version 12.5. I am already old.....