documentation for dhdt, a photohypsometric Python library

dhdt is a modular geodetic imaging framework written in Python. It uses data from imaging satellites to extract (above) surface kinematics and elevation (change). This is done via image matching techniques and geometric principles.

This library is generic, but has a preference towards open satellite data, as in recent years many space agencies have adopted an open data policy. Consequently, functions for the Sentinel-2 satellites of the Copernicus system are closest to completion.


This library has two aspects

  • photohypsometry : extracting elevation change from changing shadow cast

  • photogrammetry : extracting displacement or disparity through changes in observation time and of angle

Indices and tables