Transformez

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.

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📦 Installation

Install Transformez Install the transformez python package:

pip install transformez

Install 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 install

🐄 Quickstart

Generate 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 4979

Transform a raster directly. Transformez reads the bounds/resolution from the file.

transformez raster my_dem.tif -I mllw -O 5703

Integrate directly into your fetchez pipeline.

# Download GEBCO and shift EGM96 to WGS84 on the fly
fetchez gebco ... --hook transformez:datum_in=5773,datum_out=4979

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📚 Documentation

Would you like to know more? Check out our Official Documentation to learn about:

• The Python API: Build custom transformation into your apps.

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⚖ License

This project is licensed under the MIT License - see the LICENSE file for details.

Copyright (c) 2010-2026 Regents of the University of Colorado