Global vertical datum transformations, simplified.
Transformez is a standalone Python engine for converting geospatial data between vertical datums (e.g., MLLW ↔ NAVD88 ↔ Ellipsoid).
Transformez is part of the Continuous DEMs Project, an ecosystem of tools for modern, continuous digital elevation model generation. Originally incubated within CUDEM, the engine has evolved into a standalone datum transformation suite.
Install Transformez Install the transformez python package:
pip install transformezInstall HTDP The NGS Horizontal Time-Dependent Positioning (HTDP) software is required to perform highly accurate plate tectonic and frame transformations, you can install it with transformez!:
transformez htdp installGenerate a vertical shift grid for anywhere on Earth.
# Transform MLLW to WGS84 Ellipsoid in Norton Sound, AK
transformez grid -R -166/-164/63/64 -E 1s -I mllw -O 4979Transform a raster directly. Transformez reads the bounds/resolution from the file.
transformez raster my_dem.tif -I mllw -O 5703Integrate directly into your fetchez pipeline.
# Generate vertical datum shift grids on-demand.
fetchez transformez --src_datum mllw --dst_datum 4979 --increment 1sWould you like to know more? Check out our Official Documentation to learn about:
- The Python API: Build custom, memory-safe transformations directly into your applications.
- Offline Field Ops: Pre-fetch global FES models, VDatum grids, and NASA coastlines for offline execution (
transformez prefetch). - Live CO-OPS Data: Dynamically interpolate geodetic surfaces using live tide station offsets (
--use-stations). - Data Provenance: Learn how Transformez embeds automated metadata tags into output GeoTIFFs for strict scientific traceability.
This project is licensed under the MIT License - see the LICENSE file for details.
Copyright (c) 2010-2026 Regents of the University of Colorado