Map Projections

About the Author: Frederick Pearson has extensive experience in teaching map projection at the Air Force Cartography School and Virginia Polytechnic Institute. He developed star charts, satellite trajectory programs, and a celestial navigation device for the Aeronautical Chart and Information Center. He is an expert in orbital analysis of satellites, and control and guidance systems. At McDonnell-Douglas, he worked on the guidance system for the space shuttle. This text develops the plotting equations for the major map projections. The emphasis is on obtaining usable algorithms for computed aided plotting and CRT display. The problem of map projection is stated, and the basic terminology is introduced. The required fundamental mathematics is reviewed, and transformation theory is developed. Theories from differential geometry are particularized for the transformation from a sphere or spheroid as the model of the earth onto a selected plotting surface. The most current parameters to describe the figure of the earth are given. Formulas are included to calculate meridian length, parallel length, geodetic and geocentric latitude, azimuth, and distances on the sphere or spheroid. Equal area, conformal, and conventional projection transformations are derived. All result in direct transformation from geographic to cartesian coordinates. For selected projections, inverse transformations from cartesian to geographic coordinates are given. Since the avoidance of distortion is important, the theory of distortion is explored. Formulas are developed to give a quantitative estimate of linear, area, and angular distortions. Extended examples are given for several mapping problems of interest. Computer applications, and efficient algorithms are presented. This book is an appropriate text for a course in the mathematical aspects of mapping and cartography. Map projections are of interest to workers in many fields. Some of these are mathematicians, engineers, surveyors, geodicests, geographers, astronomers, and military intelligence analysts and strategists.

Cartographers have long grappled with the impossibility of portraying the earth in two dimensions. To solve this problem, mapmakers have created map projections. This work discusses and illustrates the known map projections from before 500BC to the present, with facts on their origins and use.

In the context of Geographical Information Systems (GIS) the book offers a timely review of Map Projections. The first chapters are of foundational type. We introduce the mapping from a left Riemann manifold to a right one specified as conformal, equiaerial and equidistant, perspective and geodetic. In particular, the mapping from a Riemann manifold to a Euclidean manifold ("plane") and the design of various coordinate systems are reviewed . A speciality is the treatment of surfaces of Gaussian curvature zero. The largest part is devoted to the mapping the sphere and the ellipsoid-of-revolution to tangential plane, cylinder and cone (pseudo-cone) using the polar aspect, transverse as well as oblique aspect. Various Geodetic Mappings as well as the Datum Problem are reviewed. In the first extension we introduce optimal map projections by variational calculus for the sphere, respectively the ellipsoid generating harmonic maps. The second extension reviews alternative maps for structures , namely torus (pneu), hyperboloid (cooling tower), paraboloid (parabolic mirror), onion shape (church tower) as well as clothoid (Hight Speed Railways) used in Project Surveying. Third, we present the Datum Transformation described by the Conformal Group C10 (3) in a threedimensional Euclidean space , a ten parameter conformal transformation. It leaves infinitesimal angles and distance ratios equivariant. Numerical examples from classical and new map projections as well as twelve appendices document the Wonderful World of Map Projections.

A map projection fundamentally impacts the mapmaking process. Working with Map Projections: A Guide to Their Selection explains why, for any given map, there isn’t a single "best" map projection. Selecting a projection is a matter of understanding the compromises and consequences of showing a 3-D space in two dimensions. The book presents a clear understanding of the processes necessary to make logical decisions on selecting an appropriate map projection for a given data set. The authors discuss the logic needed in the selection process, describe why certain decisions should be made, and explain the consequences of any inappropriate decision made during the selection process. This book also explains how the map projection will impact the map’s ability to fulfill its purpose, uses real-world data sets as the basis for the selection of an appropriate map projection, and provides illustrations of an appropriately and inappropriately selected map projection for a given data set. The authors take a novel approach to discussing map projections by avoiding an extensive inventory of mathematical formulae and using only the mathematics of map projections that matter for many mapping tasks. They also present information that is directly applicable to the process of selecting map projections and not tied to a specific software package. Written by two leading experts, this book is an invaluable resource for anyone studying or working with geospatial data, from students to experienced professionals, and will help readers successfully weigh the pros and cons of choosing one projection over another to suit a map’s intended purpose.

A revised and expanded new edition of the definitive English work on map projections. The revisions take into account the huge advances in geometrical geodesy which have occurred since the early years of satellite geodesy. The detailed configuration of the geoid resulting from the GEOS and SEASAT altimetry measurements are now taken into consideration. Additionally, the chapter on computation of map projections is updated bearing in mind the availability of pocket calculators and microcomputers. Analytical derivation of some map projections including examples of pseudocylindrical and polyconic projections is also covered. Work undertaken in the USA and USSR on the creation of suitable map projections obtained through numerical analysis has been included. The book concludes with a chapter on the abuse and misrepresentation of map projections. An invaluable reference source for professional cartographers and all those interested in the fundamental problems of mapping the Earth.

Geographic books routinely introduce map projections without providing mathematical explanations of projections and few delve into complex mathematical development or cover the breadth of projections. From basic projecting to advanced transformations, Cartographic Science: A Compendium of Map Projections, with Derivations is a comprehensive reference that offers an explanation of the science of cartography. The book is a compilation of more than a hundred map projections, from classic conics to contemporary transformations using complex variables. Starting from widely described geometric projecting onto flat paper, cylinder, and cone and then progressing through several layers of mathematics to reach modern projections, the author maximizes the application of one layer of complex mathematics before continuing on to the next. He also supplies numerous one-page tutorials that review terms and methodologies, helping minimize the challenges of unfamiliar mathematical territory. Divided into four parts, the first section examines the shape and size of the Earth, then proceeds to investigate the means for relating the curved surface to a flat surface, and addresses scaling. It goes on to cover pertinent principles of projection including literal projecting, true but synthetic projections, secantal projections, pseudocylindrical projections, and pseudoconical projections, as well as the other variants of more serious projections. The book concludes by looking at factors influencing Mean Sea Level and notes the cartographic aspects of current developments. Cartographic Science: A Compendium of Map Projections, with Derivations explains the mathematical development for a large range of projections within a framework of the different cartographic methodologies. This carefully paced book covers more projections, with gentle and progressive immersion in the mathematics involved, than any other book of its kind.

This book offers a much-needed critical approach to the intelligent use of the wide variety of map projections that are rapidly and inexpensively available today. It also discusses the distortions that are immanent in any map projection. A well-chosen map projection is one in which extreme distortions are smaller than those in any other projection used to map the same area and in which the map properties match its purpose. Written by leading experts in the field, including W. Tobler, F.C. Kessler, S.E. Battersby, M.P. Finn, K.C. Clarke, V.S. Tikunov, H. Hargitai, B. Jenny and N. Frančula. This book is designed for use by laymen. The book editors are M. Lapaine and E.L. Usery, Chair and Vice-Chair, respectively, of the ICA Commission on Map Projections for the period 2011-2015.