Earth Observing Systems

Typical for remote sensing is the investigation of the Earth’s surface and subsurface layers without direct physical contact to the medium. Most common are analyses of electromagnetic radiation reflected, scattered or emitted from the Earth’s surface to the measurement device. The radiation is commonly measured in the visible, infrared, thermal and microwave range. Cameras, lasers, scanners, radiometers and radar instruments installed on satellites, aircrafts and helicopters are the most popular remote sensing sensors.

The basic question is which properties of the Earth’s surface can be retrieved from the measured radiation? To answer this question for different surface and subsurface types, considering varying environmental conditions, we use the results of ground-based measurements that are compared with the remote sensing data, considering the technical properties of the respective sensors.

We apply theoretical models of the interaction between electromagnetic radiation and the ground to understand the characteristics of the signals that are received by the sensors. We deal with the processing and visualization of remote sensing data and use our results for comparisons with results of computer simulations that model geophysical phenomena in the Polar Regions.

In our group we focus on the ice sheets of Antarctica and Greenland, on sea ice, and on permafrost regions. Typical questions are: Which sea ice types can be separated in radar images? How do polynyas in sea ice evolve in response to meteorological and oceanic conditions? Which methods are optimal to determine sea ice and glacier movement and deformation? Which sensor combinations are optimal for classification of land cover units in permafrost regions? How can we retrieve snow accumulation rates from satellite data? The results of our analyses are incorporated in the work of other research groups.