Gebesee Database for the enhancement of crop monitoring applications: evolution of plant physiology, soil moisture, surface reflectance and atmospheric conditions on the agricultural Gebesee test site (central Germany) in 2016

Ground reference data are essential for the calibration, update and validation of empirically and physically based models as well as hybrid methods that facilitate crop monitoring with the help of Earth Observation data. This database contains in situ measured values from 2016 for various parameters characterizing vegetation, soil and atmosphere conditions all of which are required to test and validate the Earth Observation Land Data Assimilation System (EO-LDAS). This new database is complementary to another database for the growing seasons in 2013 and 2014 that was previously published by Truckenbrodt & Baade (2017; doi:10.1594/PANGAEA.874251) and has been described in detail by Truckenbrodt & Schmullius (2018). In 2016, ground reference data were collected for five crop types (i.e., winter barley, winter wheat, spring wheat, potato and sugar beet) grown on the agricultural Gebesee test site (central Germany). Between May and October, hyperspectral surface reflectance, information on the evolution of biophysical and biochemical plant parameters (like leaf area index, biomass and leaf chlorophyll content), phenology, leaf structure, soil moisture, atmospheric states and illumination conditions were recorded. The field working days were preferentially scheduled for days with expectedly low cloud coverage and close to overflights of Sentinel-2, Landsat 7 and 8. Each crop type was investigated on average every 16 days on at least one elementary sampling unit (ESU). The data collection for potato and winter wheat was complemented with up to two additional ESUs on single field working day. All ESUs are designed as a square with a diagonal length of 24 m. On the diagonal from the most southwestern to the most northeastern corner of the ESU five secondary sampling points (SSPs) are distributed: at 0 m (SSP00), 8 m (SSP08), 12 m (SSP12), 16 m (SSP16), and 24 m (SSP24). The corner coordinates were determined with a differential Global Navigation Satellite System (dGNSS). A set of dGNSS recorded ground control points (GCPs) and check points (CPs) has been provided by Truckenbrodt & Baade (2017; doi:10.1594/PANGAEA.874247) and allows for a solid geo-referencing of satellite images depicting the agricultural Gebesee test site.