Function navtk::navutils::ecef_to_local_level

Function Documentation

Vector3 navtk::navutils::ecef_to_local_level(const Vector3 &P0e, const Vector3 &Pe)

Convert ECEF location to fixed local-level NED frame location.

In general, an NED frame is defined as a local-level frame at a specified location. In this function, the location of the origin of the NED frame is expressed in ECEF coordinates as \(\textbf{p}_0^{\text{ECEF}}\). Specifying \(\textbf{p}_0^{\text{ECEF}}\) creates a local-level NED frame at that location, which we will call the \(\text{NED}_{\textbf{p}_0}\) frame.

This function converts the ECEF position of an arbitrary point \(\textbf{p}^{\text{ECEF}}\) to a representation of that same point coordinatized in the \(\text{NED}_{\textbf{p}_0}\) frame. Note that this more than just a rotation from ECEF to NED. There is also a translation to accommodate the different origins of the two coordinate frames ( \(\text{ECEF}\) and \(\text{NED}_{\textbf{p}_0}\)).

See also

Coordinate Frames for definitions of ECEF and NED frames.

See also

local_level_to_ecef() for the companion function that converts in the opposite direction.

Parameters

  • P0e – \(\text{NED}_{\textbf{p}_0}\) frame origin expressed in ECEF coordinates (meters) = \(\textbf{p}_0^{\text{ECEF}}\)

  • Pe – Location of point in ECEF frame (meters) = \(\textbf{p}^{\text{ECEF}}\)

Returns

Location of Pe expressed in the fixed local-level \(\text{NED}_{\textbf{p}_0}\) frame (meters).