One of the facets of our work that makes it different from other software development is the need to deal with geographic projections and coordinate systems. Projection systems are the mechanisms by which we spread a semi-spherical Earth onto a flat surface. Google, Microsoft, Yahoo and ESRI use global coordinate system called Web Mercator for their online systems. Here in Philadelphia, the local municipalities use the NAD 1983, State Plane, South Pennsylvania coordinate system with a Lambert Conformal Conic projection. While satellites and improved measurements have changed and improved our coordinate systems as well as given us a few new ones, we have not actually seen that many new projections in recent years.
But now there’s not just a new projection but a whole family of new ones based on an alogorithmic approach developed by Jack van Wijk, a Netherlands computer scientist at the Eindhoven University of Technology. This news is actually almost two years ago, but Dr. Wijk was recently awarded the Henry Johns award by the British Cartographic Society, so it was back in the news.
Projections are always about trying to square a circle but failing – none of them can get it right, and they all distort, only varying in terms of the type and degree of distortion. The Mercator projection, for example, preserves shape but sacrifices an accurate size of those shapes, while the Peters projection preserves size while sacrificing shape.
Dr. van Wijk’s new projections are called Myriahedral, representing projections that cut the globe into a polyhedron composed of large numbers of facets. The development is significant because it manages to reduce the angular demormation (shape) by preserving area as well, essentially squaring the circle. It represents a whole new class of projections because, depending on the parameters, the result will change with many maps being possible. By allocating the most weight to land masses, a map is generated that lines up the continents. By shifting the weight to the oceans, the algorithm produces a single giant sea surrounded by land.
Read the original article: The Cartographic Journal, DOI: 10.1179/000870408×276594
