1. German Aerospace Center (DLR), Remote Sensing Technology Institute Rutherfordstraße 2 12489 Berlin Germany
2. Foundation for Research and Technology—Hellas (FORTH) Institute of Applied and Computational Mathematics N. Plastira 100, Vassilika Vouton 70013 Heraklion Greece
3. Here+There Mapping Solutions Richard‐Sorge str 65 Berlin Germany