Axes of the coordinate frame E (Earth-Centred, Earth-Fixed, ECEF) when the
x-axis points to the North Pole.
The x-axis points to the North Pole, y-axis points towards longitude +90deg
(east) and latitude = 0. This choice of axis directions ensures that at zero
latitude and longitude, N (North-East-Down) has the same orientation as E. If
roll/pitch/yaw are zero, also B (Body, forward, starboard, down) has this
orientation. In this manner, the axes of E is chosen to correspond with the
axes of N and B.
Axes of the coordinate frame E (Earth-Centred, Earth-Fixed, ECEF) when the x-axis points to the North Pole.
The x-axis points to the North Pole, y-axis points towards longitude +90deg (east) and latitude = 0. This choice of axis directions ensures that at zero latitude and longitude, N (North-East-Down) has the same orientation as E. If roll/pitch/yaw are zero, also B (Body, forward, starboard, down) has this orientation. In this manner, the axes of E is chosen to correspond with the axes of N and B.