dhdt: a Python library to transform shifting shadows to glacier elevation change

The free and open data policy of the Landsat legacy and the Sentinel-2 satellite constellation have enhanced our knowledge considerably. This enrichment is due to an increase in spatial spread; from glacier change at targeted glaciers, to a coverage at regional or global scale. Procedures for snow cover mapping and glacier outline product generation from such multi-spectral data are well matured. Though more potential is present for glacier specific information in such data sources.

Recently several studies presented the capabilities of elevation change extraction via shadow cast detection. Though these are at the proof of concept stage, as many steps are based on heuristics and manual adjustments/measurements.

Here we present a fully automatic pipeline which is based on an open source library, which we developed. The emphasis of this code base, which we named dhdt, is focused on large scale processing. Hence, all steps are fully automatic and structured so distributed processing is possible. It generates spatial temporal elevation changes, over small mountain glaciers. We hope, this will advance the glaciological community forward, giving a new instrument in its toolbox.