ABSTRACT
This chapter focuses on selecting projections for phenomena that are considered continuous and smooth. It utilizes two different datasets to demonstrate how projection choice can influence the creation, appearance, and interpretation of isarithmic maps based on true point locations. The first dataset is a collection of 13,241 oil wells drilled in the North Sea. The second dataset is global sea surface temperature, which use to illustrate the impact of projection on the visual tasks associated with reading isarithmic maps. The chapter discusses the impact of projection distortion on calculation of the interpolated data values represented in isarithmic maps. It describes the results of distance calculations using a reference ellipsoid, grid system, two equidistant projections - azimuthal equidistant planar and plate carree cylindrical projection, and one near-conformal projection. The chapter examines how projection impacts design choices so that the final map aligns with the visual analysis tasks that map readers typically perform.
