Ecef

ECEF

ECEF(Earth-Centered, Earth-Fixed), also known as ECR (Earth Centered Rotational) is a Cartesian coordinate system, and is sometimes known as a "conventional terrestrial" system. It represents positions as an X, Y, and Z coordinate. The point (0,0,0) is defined as the center of mass of the Earth, hence the name Earth-Centered. Its axes are aligned with the International Reference Pole (IRP) and International Reference Meridian (IRM) that are fixed with respect to the surface of the Earth, hence the name Earth-Fixed. This term can cause confusion since the Earth does rotate with the axis as opposed to an inertial system such as ECI, and is therefore alternatively called ECR.