Spatially thin out trajectory of 3D points

Hello everyone,

I have a trajectory of 3D positions on the earth (geodetic coordinates latitude, longitude and ellipsoidal height).

It consists of standstill, low-dynamic and high-dynamic parts.

For plotting, memory and performance reasons I would like to spatially thin out my list of points in the trajectory (like for example keeping only points that are >0.5 m apart).

So I would like to ask if there is already a built-in function for this in MATLAB (or maybe the Mapping Toolbox) that I missed, or if I will have to write my own function?

Greetings

Answer 1

[Rob Comer]

You'll have to write your own function, but the ecefOffset function in Mapping Toolbox can help. Try something like this (assuming h is ellipsoidal height in meters):

[deltaX,deltaY,deltaZ] = ecefOffset(wgs84Ellipsoid,...
    lat(1:end-1),lon(1:end-1),h(1:end-1),lat(2:end),lon(2:end),h(2:end));
delta = hypot(hypot(deltaX,deltaY),deltaZ);

Then look for elements of delta that are less than 0.5.