MATLAB: In “lla2ecef” function, is altitude with respect to sea level or ellipsoid model

Aerospace Toolbox

I am using "lla2ecef" function and I want to know if altitude parameter that it accepts, is with respect to sea level or ellipsoid model. In other words, is it height above sea level or something else?

Best Answer

The altitude parameter, in "lla2ecef" function, is with respect to planetary ellipsoid. With that said, few points for you to consider:
MSL (mean sea level) is a close approximation to the geoid. There is a 'geoidheight' function in the Aerospace Toolbox that can be useful for computing with respect to sea level. The output of this function is the difference between the ellipsoid and the geoid at a particular lat/lon location. Here is some information about the difference between these datums: https://earth-info.nga.mil/GandG/publications/vertdatum.html
Documentation for 'geoidheight' function : https://www.mathworks.com/help/releases/R2020b/aerotbx/ug/geoidheight.html
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