Featured Story
Why Elevation Follows Gravity: The Geoid Beneath Every Height
GNSS measures height above a mathematical ellipsoid, but practical elevation depends on gravity, the geoid, and a physical definition of level.
Read ArticleStories by Subject
Mountains & Geodesy
Triangulation, elevations, gravity, geodesy, and the measurement of high terrain.
5 articles
Recent Articles
Surveying Beneath Ice: Mapping Continents Hidden From View
Airborne radar, satellite altimetry, GNSS, gravity, and decades of field surveys reveal the mountains, canyons, lakes, and basins concealed beneath continental ice.
Surveying the Highest Peak, Part 3: GPS, Geoids, Snow, and the Modern Height of Everest
Why modern Everest measurements depend on GNSS, gravity, snow depth, reference frames, and a clear definition of height.
Surveying the Highest Peak, Part 2: How Peak XV Became Mount Everest
The distant observations, calculations, corrections, and people behind the first accepted height of the world’s highest mountain.
Surveying the Highest Peak, Part 1: Building the Great Trigonometrical Survey
How baselines, giant theodolites, triangulation, and an immense field organization carried a geodetic network across India.