Documentation

dcmecef2ned

Convert geodetic latitude and longitude to direction cosine matrix

Syntax

n = dcmecef2ned(lat, lon)

Description

n = dcmecef2ned(lat, lon) calculates the direction cosine matrix, n, for a given set of geodetic latitude and longitude, lat, lon. lat is an m array of geodetic latitudes. lon is an m array of longitudes. Latitude and longitude values can be any value. However, latitude values of +90 and -90 may return unexpected values because of singularity at the poles. n returns a 3-by-3-by-m matrix containing m direction cosine matrices. n performs the coordinate transformation of a vector in Earth-centered Earth-fixed (ECEF) axes into a vector in north-east-down (NED) axes. Geodetic latitudes and longitudes are input in degrees.

Examples

Determine the direction cosine matrix from geodetic latitude and longitude:

lat = 45;
lon = -122;
dcm = dcmecef2ned(lat, lon)

dcm =

0.3747    0.5997    0.7071
0.8480   -0.5299         0
0.3747    0.5997   -0.7071

Determine the direction cosine matrix from multiple geodetic latitudes and longitudes:

lat = [45 37.5];
lon = [-122 -85];
dcm = dcmecef2ned(lat, lon)

dcm(:,:,1) =

0.3747    0.5997    0.7071
0.8480   -0.5299         0
0.3747    0.5997   -0.7071

dcm(:,:,2) =

-0.0531    0.6064    0.7934
0.9962    0.0872         0
-0.0691    0.7903   -0.6088 