Function navtk::navutils::meridian_radius

Defined in File navigation.hpp

Function Documentation

double navtk::navutils::meridian_radius(double latitude)

Calculate the meridian radius of curvature (termed \(R_N\) in Titterton and Weston, sometimes called \(R_M\), where “M” stands for meridian).

This is the radius of curvature in the north-south direction (i.e., along a meridian), which varies according to latitude. The radius of curvature can be used to relate change in latitude ( \(d\phi\)) to change in the north direction in a local-level frame expressed in meters ( \(d\text{North}\)):

\( d\text{North} = R_N d\phi \)

References:

Strapdown Inertial Navigation Technology 2nd ed, Titterton and Weston, eq. 3.83

WGS-84 Reference System (NIMA report TR 8350.2), page 7-5.