3DM-CX5-GNSS/INS
User Manual
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4.3.2
North East Down (NED) Frame
The North-East-Down (NED) frame is a local coordinate frame, which is formed by a tangent plane
located at a particular point (current coordinates) on the WGS84 reference ellipse. The NED frame
is constructed with the (true) North vector along the line of longitude, the East vector along the line
of latitude, and the Down vector normal to and towards the tangent plane (
). The assumption when using the NED frame is that the local surface can be
reasonably approximated by a flat plane. For most applications, this assumption is valid and
provides a more intuitive reference frame for expressing velocity and attitude information than a
global frame.
The 3DM-CX5-GNSS/INS reports velocity in this frame and attitude with respect to this frame.
Figure 18. North East Down Frame
