For the calculation of the data "AIS Vessel Density", the data of the Universal Shipborne Automatic Identification System (AIS) were evaluated with regard to various parameters and ship types under stochastic aspects. The data are requested once a year for the past year from the European Maritime Safety Agency (EMSA). Among others, the information is collected and stored for the purpose of securing maritime traffic and is used for the manufacture of products produced for navigation by the Federal Maritime and Hydrographic Agency (BSH). The data "AIS Vessel Density" represent the mean spatial density distribution of the ships. The mean spatial ship density is the current number of ships that could be expected in a defined area (grid cell) at any time during a reference period under consideration. The counting distinguishes between five types of vessels: fishing vessels, cargo vessels, tankers, passenger vessels and all vessels. For more information, please visit: https://gdi.bsh.de/en/data/Vessel-Density-Annual-Values-timeslider_Dokumentation_Schiffsdichte_DE.pdf

This collection contains tropospheric NO2 columns for Germany and surrounding areas derived from Sentinel-5P/TROPOMI Level-1B data. The Sentinel-5P tropospheric NO2 data is generated by DLR and provided in the framework of the mFUND-Project "S-VELD". The tropospheric NO2 data are vertical column densities with the unit "µmol/m2". Sentinel-5P observes Germany once per day at ~12:00 UTC. These daily observations are gridded onto a regular UTM grid. The day and measurement time are included in the netCDF data file. Only tropospheric NO2 data for cloud-free Sentinel-5P measurements are provided (cloud fraction < ~0.2). Sentinel-5P cloud fraction data is included in this collection as well.