The Equivalency of the Tangent and Secant Lambert Conformal Map Projections

Abstract

There is a popular misconception that the secant form of the Lambert conformal map projection is ?better? than the tangent form. It is shown here that the two forms are equivalent; they are different only in the sense that the scale of the map quoted is usually true at the two secant latitudes for the secant projections and at the single tangent latitude for the tangent projection.