Difference in Terrain Elevation data from Cesium World Terrain and Google terrain

CesiumJS
1

I am trying to plot some 3D models on Cesium Terrain we are receiving altitude with respect to Google terrain altitude due to the difference between both terrain altitudes there is difficulty in plotting the geometries. Is there a way to solve this?

I tried using sampleTerrainMostDetailed but there is a difference in Height

2

I don’t know the Source of Google’s elevation data, but the sources for Cesium World Terrain are described here.

Do you have a particular area of interest and have “better” data? You could upload it to Cesium ion for use in your application. Do you have any examples, that you can share, where you’re seeing differences?

3

It’s third-party software that is using Google terrain, right now I can’t show any values from that.

Also because of this issue, we are trying to convert Cesium terrain into Google terrain and found this but I couldn’t find the URL or code snippet for integration

4

I don’t know why, but I have also noticed a significant difference between the elevation on the Cesium terrain and the elevation of mountains according to conventional maps. Typically the Cesium elevation is less than the actual elevation by 50 to 100m. (Also, don’t assume Google Earth is the benchmark). Can someone tell me why this is perhaps an approximation of the WGS84 ellipsoid?

5

Hi @QuartzReservoir,

This thread might help answer your question! Specifically, this comment. Let me know if that’s not what you’re looking for!

Best,
Matt

6

Thanks, that’s a bit clearer, although in practice we usually are interested in the height according to conventional maps

7

Hi @QuartzReservoir, in which mountain range were you observing this height difference?

I’m interested to know if the difference between Cesium terrain elevation and your expected value is explainable by the geoid vs ellipsoid height difference. If I’m reading this image correctly:
Earth Gravitational Model 1996 - Geoid - Wikipedia
the ellipsoidal height might be 50-100m less than the geoid height in the Rockies and the Himalayas, but not in the Andes.

8

I found the EMG 96 conversion scripts and made some comparisons.

Elevated Lakes are correct.

Some mountains are too low, possibly because of lack of resolution in the terrain sampling?

9

Here is some demo code

Elevation.zip (1.8 MB)