Reckon position along meridian
phi2 = meridianfwd(phi1,s,ellipsoid)
phi2 = meridianfwd(phi1,s,ellipsoid) determines the geodetic latitude phi2 reached by starting at geodetic latitude phi1 and traveling distance s north (positive s) or south (negative s) along a meridian on the specified ellipsoid. ellipsoid is a referenceSphere, referenceEllipsoid, or oblateSpheroid object, or a vector of the form [semimajor_axis eccentricity]. Latitudes phi1 and phi2 are in radians, and s has the same units as the semimajor axis of the ellipsoid.