[Newbie alert: both to Cesium and to satellite terminology and various time/space reference frames. Feel free to point me at other resources if this query is to rudimentary for the group.]
I don’t know how to transform the ECI TEME coordinates into Cesium.Cartesian3 coordinates. It looks like Cesium.Transforms.computeTemeToPseudoFixedMatrix() would help but I’m out of my league here and I haven’t found anything in the docs that are high-level enough for me, vs. API reference pages. I’m able to tweak the Sandbox example to render billboards mapping Cesium.Cartographic.fromDegrees() and billboard.add(), but don’t know how to get ECI TEME into the right reference frame. I’m clueless about Cartographic vs. Cartesian references, all new to me, sorry.