This problem is now closed. Keep an eye out for the Sept Issue Problem
A Problem of Global Proportions
What geodetic latitude represents 75% of the GRS 80 ellipsoid’s volume from South to North? Determine to nearest second.
||Norm Hanson||18 Jun||Slightly off because Norm used an incorrect semi-minor axis value and computed the geocentric latitude.|
|2||8||5||15||Larry Schmit||02 Jul||Larry admitted his “son Tim did most of the work.” They attempted a triple integral but their solution was a little short on details. Their latitude (also geocentric), was off by quite a bit.|
What’s the difference between geodetic and geocentric latitude? Nothing, if you’re on a sphere. On an ellipsoid, the geocentric latitude, Ψ, is the angle from the semi-major axis to a line connecting the surface point and semi-major and -minor axes intersection. The geodetic latitude, Φ, is the angle from the semi-major axis to the normal through the surface point (a normal is perpendicular to the ellipsoid).
They are related through the equation:
At 0° and 90° N and S, geodetic and geocentric latitude are equal.
updated 20 Aug '18