# My Entity height data is sea-level, but Cesium thinks in height above ellipsoid.

**URL:** <https://community.cesium.com/t/my-entity-height-data-is-sea-level-but-cesium-thinks-in-height-above-ellipsoid/2233>\
**Category:** CesiumJS\
**Created:** [March 24, 2015, 2:48pm UTC](https://community.cesium.com/t/my-entity-height-data-is-sea-level-but-cesium-thinks-in-height-above-ellipsoid/2233 "2015-03-24T14:48:45Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![thomlep](https://avatars.discourse-cdn.com/v4/letter/t/43a26b/32.png) [@thomlep](https://community.cesium.com/u/thomlep)\
**Post date:** [March 24, 2015, 2:48pm UTC](https://community.cesium.com/t/my-entity-height-data-is-sea-level-but-cesium-thinks-in-height-above-ellipsoid/2233/1 "2015-03-24T14:48:45Z")

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Hello,

I've noticed a disagreement between my height data in my CZML (sea level values) and the calculated (interpolated) height reported at runtime ( I see the runtime values by attaching a listener and watching the Entity position change as the Entity travels).

So, we know that height is taken as height above ellipsoid ( see [http://cesiumjs.org/Cesium/Build/Documentation/Cartographic.html](http://cesiumjs.org/Cesium/Build/Documentation/Cartographic.html) ), and that the ellipoid does not necessarily follow sea level.

Question: Do I need to attach a terrain provider to correct this problem?

Thanks !

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**Author:** ![Aaron\_Bird](https://avatars.discourse-cdn.com/v4/letter/a/cab0a1/32.png) [@Aaron\_Bird](https://community.cesium.com/u/Aaron_Bird)\
**Post date:** [March 24, 2015, 8:53pm UTC](https://community.cesium.com/t/my-entity-height-data-is-sea-level-but-cesium-thinks-in-height-above-ellipsoid/2233/2 "2015-03-24T20:53:20Z")

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I posted a similar question a while back. This may help

[http://cesiumjs.org/forum.html?place=topic%2Fcesium-dev%2FXz6\_FnCuGNA%2Fdiscussion](http://cesiumjs.org/forum.html?place=topic%2Fcesium-dev%2FXz6_FnCuGNA%2Fdiscussion)

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**Author:** ![thomlep](https://avatars.discourse-cdn.com/v4/letter/t/43a26b/32.png) [@thomlep](https://community.cesium.com/u/thomlep)\
**Post date:** [March 24, 2015, 9:22pm UTC](https://community.cesium.com/t/my-entity-height-data-is-sea-level-but-cesium-thinks-in-height-above-ellipsoid/2233/3 "2015-03-24T21:22:13Z")

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I found that discussion, which is very good. Thanks. The title is "CesiumTerrainProvider V VRTheWorldTerrainProvider Heights"

Thanks Aaron!

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**Author:** ![Hyper\_Sonic](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/hyper_sonic/32/2255_2.png) [@Hyper\_Sonic](https://community.cesium.com/u/Hyper_Sonic)\
**Post date:** [March 24, 2015, 9:54pm UTC](https://community.cesium.com/t/my-entity-height-data-is-sea-level-but-cesium-thinks-in-height-above-ellipsoid/2233/4 "2015-03-24T21:54:58Z")

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Links to posts don’t work if you use the [cesiumjs.org](http://cesiumjs.org) domain, though I see that tho managed to find it anyways. That’s why instead of going to [http://cesiumjs.org/forum.html](http://cesiumjs.org/forum.html) I goto [https://groups.google.com/forum/#!forum/cesium-dev](https://groups.google.com/forum/#!forum/cesium-dev) instead as making links from there actually work.

This just leads to main forum page

[http://cesiumjs.org/forum.html?place=topic%2Fcesium-dev%2FXz6\_FnCuGNA%2Fdiscussion](http://cesiumjs.org/forum.html?place=topic%2Fcesium-dev%2FXz6_FnCuGNA%2Fdiscussion)

This is what google groups gives as a link

[https://groups.google.com/d/msg/cesium-dev/Xz6\_FnCuGNA/g](https://groups.google.com/d/msg/cesium-dev/Xz6_FnCuGNA/g)

Then it changes to this form once entered

[https://groups.google.com/forum/#!msg/cesium-dev/Xz6\_FnCuGNA/g](https://groups.google.com/forum/#!msg/cesium-dev/Xz6_FnCuGNA/g)

I tried removing the last character on the link but it wouldn’t work anymore.

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<div class="post-metadata">

**Author:** ![Hyper\_Sonic](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/hyper_sonic/32/2255_2.png) [@Hyper\_Sonic](https://community.cesium.com/u/Hyper_Sonic)\
**Post date:** [March 24, 2015, 10:01pm UTC](https://community.cesium.com/t/my-entity-height-data-is-sea-level-but-cesium-thinks-in-height-above-ellipsoid/2233/5 "2015-03-24T22:01:06Z")

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I tried changing all the %2F to forward slashes  
[http://cesiumjs.org/forum.html?place=topic/cesium-dev/Xz6\_FnCuGNA/discussion](http://cesiumjs.org/forum.html?place=topic/cesium-dev/Xz6_FnCuGNA/discussion)

But it still didn’t work.