Geodesic and Great Elliptic Arc Deviations on Triaxial and WGS84 Ellipsoids

Over 600,000 records analyzing geodesic uniqueness and lateral deviation comparisons on triaxial and WGS84 ellipsoids. Developed by Ziqiang Li and updated in 2026, it supports research into approximating geodesic polygons via great elliptic arcs using data derived from Karney's test sets and uniform sampling.

Use Cases

• Benchmarking lateral deviation errors using the 'Theoretical lateral deviation' and 'Actual lateral deviation' columns
• Classifying geodesic path anomalies using the 'Reason for non-uniqueness' labels in non_unique.log
• Modeling maritime boundaries using the vertex data from the U.S. Caribbean Sea Emission Control Area

Strengths

• Contains 500,000 geodesic records derived from Karney's established triaxial ellipsoid test set
• Includes 100,000 uniformly sampled arcs on the WGS84 ellipsoid for statistical significance
• Provides specific geometric classifications for non-uniqueness such as 'antipodal-umbilical'

Limitations

• Triaxial ellipsoid analysis is restricted to a single set of axes (a=sqrt(2), b=1, c=1/sqrt(2))
• Geographic scope for real-world application is limited to the 54-vertex U.S. Caribbean Sea Emission Control Area

Provenance

Source

Harvard Dataverse / Ziqiang Li

Collection Method

Derived from Karney's 'Test set of geodesics on a triaxial ellipsoid' and uniform random sampling

Freshness

Last updated March 2026.

Geography

Global (WGS84) and U.S. Caribbean Sea