The Cartographic Projections of R.V. Putninš

Abstract

This article is a re-examination of the 12 pseudocylindrical world map projections developed by R.V. Putninš. Projection properties, graticule shapes, and formulae are introduced. The principal aims of this article are the derivation of distortion formulae and appreciation of each projection's quality. Projections are assessed on the basis of global distortion characterization, labelled Q: Q is the ratio of the part of globe represented on the map with permissible distortion to the area, expressed as a percentage of the whole globe. Different combinations of permissible limits of angular and areal distortion are analysed. Maximum angular distortion of 40° and a 1.5 multiple of the smallest areal distortion are taken to be representative distortion limits. The final winner in the sequence of Putninš projections is the Putninš PI'. It is comparable to the best widely used world map projections.