Dear Cesium Support Team
Hello.
I would like to know which geoid model is applied for height calculations of “Japan Regional Terrain”.
Thank you.
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Hi @cccCesium
There are a couple ways to answer this question.
If you are interested in how the processed terrain is used, then the answer is all terrain heights in a quantized mesh are relative to the WGS84 ellipsoid.
If you are interested in what geoid model was used to tile the source data, then I would refer you to the source data provider - Japan’s GSI and their FAQ section here. Also the Geoid Survey Website provides additional information.
Please let me know if this helps answer your question
Dave
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Dear Mr. Dave Braig,
Thank you for your response.
I wanted to know which geoid model is being used when tiling elevation data from Geospatial Information Authority of Japan (GSI) as ellipsoidal heights on the Cesium WGS84 ellipsoid.
I thought this might fall under the domain of implementation on Cesium Ion rather than the original elevation data provided by Geospatial Information Authority of Japan.
Specifically, while EGM96 is provided for tools like the Ion Pipeline Tool and various tilers in Cesium Ion, I would like to know whether EGM96 is also used for generating the Japan Regional Terrain, or if “GSIGEO2011” is used instead, or perhaps if the input data originally contained ellipsoidal heights.
Thank you.
The data for the Japan Terrain data was converted from the source using the ellipsoidal height from GSIGEO2011 to match PLATEAU data.
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Dear Mr. Dave Braig,
That’s exactly what I wanted to know.
Thank you.
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