Guides
Plain-language explainers on the technology behind digital maps: how location services work, the math of distance and direction, why navigation is harder than it looks, and how location data is organized.
A Guide to Mapping and Location APIs
The jobs a mapping API can do, from base maps and place search to routing and geocoding, and the well-known providers for each.
Distance, Bearing, and Position on a Sphere
The standard formulas for distance and direction between two points on Earth, how they compare, and a calculator to try them.
Why "What's Ahead?" Is a Hard Question
Finding what is near you on a map is easy. Finding what is ahead of you on the road is not. A look at why, and at the broad ways navigation software approaches it.
Grids, Tiles, and Organizing Location Data
How software finds nearby places quickly among millions: coordinate grids, geohash, map tiles, S2, H3 and tree indexes compared.