Automatic interpolation of phenological phases in Germany

Abstract

The German joint project DeCover 2 is developing a methodological framework to cope with the increasing demand for up-to-date land cover information using remote sensing techniques. New satellite systems like RapidEye provide both data of high geometric resolution and high repetition rates. Because of the Germany-wide diversity of natural conditions, same acquisition dates don't correspond to same phenological phases. Thus, a phenological structuring of the available imagery over the year is needed for the assessment of Rapid-Eye imagery regarding their suitability for the classification and distinction of vegetation classes. On the example of the phenological phase ‘Yellow Ripeness’ of Winter Wheat in 2010, the presented algorithm demonstrates for the total area of Germany how daily phenological phases can be automatically interpolated on demand, in real-time and considering interpolation accuracies. As input, daily provided point data on temperature and phenological phases from the extensive network of the German Weather Service as well as a SRTM digital elevation model are used. The modeling results enable the identification of temporal phenological windows for specific test sites.