Jan 30, 2023 · Fundamentals

Understanding Map Projections: From Geographic to Web Mercator and Tile Services

This article explains the fundamentals of geographic and projected coordinate systems, details the Mercator and Web Mercator projections, introduces EPSG standards, discusses China's GCJ02 and BD09 offsets, and describes common GIS data services and tile‑based rendering techniques.

GISOGCTile Services

0 likes · 19 min read

Understanding Map Projections: From Geographic to Web Mercator and Tile Services

Zhengtong Technical Team

Mar 18, 2022 · Fundamentals

Spatial Coordinate Reference Systems and Transformations for 3D GIS Applications

This article explains the fundamentals of geodetic and Earth‑centered coordinate systems, their mathematical relationships, and how to convert between geodetic latitude/longitude/height, ECEF, ENU, and Web Mercator coordinates, providing detailed derivations, diagrams, and a C++ implementation example.

3D mappingCoordinate TransformationECEF

0 likes · 15 min read

Spatial Coordinate Reference Systems and Transformations for 3D GIS Applications