Module geodesy.projection.transverse_mercator
Bounded generic Transverse Mercator with EPSG 9807 parameter semantics.
TransverseMercator is a prepared projection object for repeated forward, reverse, and conformal-factor evaluation. It deliberately separates generic Transverse Mercator mathematics from UTM zoning policy and precomputes ellipsoid/series/origin state instead of rebuilding it for each point.
Standards
Public operation parameters and semantics follow EPSG method 9807 -- Transverse Mercator.
Domain
The public forward contract is bounded to non-polar points within 60 degrees of the central meridian, with documented representation-aware reverse and boundary semantics. Supported ellipsoids satisfy the operation-specific flattening domain.
Units
False easting, false northing, projected coordinates, and ellipsoid axes use the same caller-selected linear unit. Scale is dimensionless.
Numerics
Uses a Krueger/Karney series formulation with precomputed coefficients, stable transcendental forms, Clenshaw evaluation, and safeguarded reverse iteration. Public float uses double working precision and order 6; double/real use the documented order-8 policy.
Performance
Projection coefficients and origin-dependent terms are prepared once. Repeated checked forward/reverse/factor operations are allocation-free. Controlled release-mode benchmarks are retained in the repository.
Validation
Qualified over the bounded domain with exact/reference corpora, GeographicLib exact/reference implementations, PROJ differential tests, boundary/property tests, scalar-specific tests, and compiler/platform matrices.
See Also
UtmProjection, ConformalProjectionFactors,
GeographicCoordinate, ProjectedCoordinate
Date
September 26, 2026
Structs
| Name | Description |
|---|---|
TransverseMercator
|
Prepared bounded Transverse Mercator projection. |