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.

Methodology

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

Application domains

This library can be used for a multitude of purposes, though the main focused lies towards the following products:

• glacier elevation change

• glacier velocity

• ocean circulation

• natural mass movements

• earthquake displacements

Guide

Getting started

• getting started
  • about
  • prerequisites
• tutorials
  • Search for Sentinel-2 data from the Copernicus Open Access Hub
  • Shadow detection in muli-spectral imagery
  • Enhance the shadow of a grayscale image
  • Find the shadow edge in an image
  • Create elevation model on the same grid as satellite tile

Library

• modules
  • generic
    • input-output of mapdata
    • handle Sentinel-2 imagery
    • handle Landsat imagery
    • handle RapidEye imagery
  • input
    • read Sentinel-2 (meta)data
    • read Landsat (meta)data
    • read Terra ASTER data
    • read RapidEye data
    • read PlanetScope data
    • read VENµS data
  • preprocessing
    • image transforms
    • color transforms
    • acquisition geometry
    • aquatic transforms
    • snow transforms
    • shadow transforms
    • shadow filters
    • composition and geometry of the atmosphere
  • processing
    • organization
    • frequency filters
    • frequency correlators
    • spatial correlators
    • phase angle estimators
    • subpixel localization
    • frequency metrics
    • correlation metrics
  • postprocessing
    • displacement filters
    • solar tools
    • terrain tools
  • auxilary
    • handle CopernicusDEM
    • handle Randolph glacier inventory
    • handle ERA5
    • handle land and sea regions

Background

• theory

Indices and tables

• Index

• Module Index

• Search Page