Digital Twin 3D Geospatial Coordinate & ECEF Guide

3D Geospatial Coordinate Concepts

• ECEF (Earth-Centered Earth-Fixed): 3D Cartesian system (X, Y, Z in meters) with origin at Earth's center of mass. Standard for 3D Tiles & WebGL engines.
• Ellipsoidal vs Orthometric Height: WGS84 GPS receivers measure height above the mathematical ellipsoid, whereas topographic maps use Geoid height (Mean Sea Level).