| pe_q |
Calculates the meridional arc distance from the equator
double pe_q (double a, double e2, double phi);
| a, e2 | Semimajor axis and eccentricity squared of the spheroid |
| phi | Geographic latitude (measured in radians) of the point |
Meridional arc distance to the point is the distance measured from the equator along the meridional ellipse to the point.

where
![]()
Meridional arc distance to the point