I am given an ellipse represented by a quadruple (major, minor, center, azimuth) where major,minor are the ellips's axis length in meters, the center is the WGS84 coordinates of the ellipse's center given in a (lat, lon) form. The azimuth is the angle of the ellipse relative to the north axis.
I want to transform this representation to one which uses degrees only. My attempt was to consider the earth a perfect sphere, and associate the major axis to the latitude distance and the minor axis to the longitude distance. Additionally, I take into account the latitude when computing the longitude distance (standard distance between two points on a sphere when one advances along the azimuthal axis). Unfortunately, when I draw the resulting ellipse's WKT, it does not match the original ellipse WKT.
I don't think that this difference is caused by the spherical assumption, but by a more serious flaw. One thought I had is that the major/minor are movements in meters along the ellipse's axes, which are not aligned with the polar/azimuthal axes (which are determined by the azimuth of the ellipse), in which case I have no idea how to proceed.
This seems like a rather trivial case, but unfortunately I wasn't able to find any references.