Approximations, Errors, and Misconceptions in the Use of Map Projections

Table 5

Meridian converge angle for the Universal Transverse Mercator projection, Zone 30 N (central meridian −3°), for different location (coordinates and ) of base points.

Description of point location
Middle latitudes, near the central meridian	40	−2.5	0.3
Middle latitudes, far from the central meridian	40	−0.5	1.6
Low latitudes, near the central meridian	7	−2.5	0.06
Low latitudes, far from the central meridian	7	−0.5	0.3
High latitudes, near the central meridian	80	−2.5	0.5
High latitudes, far from the central meridian	80	−0.5	2.5

Note that unlike arc-to-chord values in Table 4, of the order of arc-seconds, meridian convergence values may be of the order of degrees.