Section 1.2: Global Geomonitoring and Gravity Field

Head of Section: Prof. Dr. F. Flechtner

Our prime research field is the precise survey of the shape of the Earth, its static and time-variable gravitational field and its orientation in space. For this we develop, operate and analyze modern gravity satellite missions (CHAMP, GRACE, GOCE, GRACE-FO) and make use of terrestrial and airborne gravimetry for regional analysis or high resolution gravity field modeling in combination with satellite data. We use the signals of high-altitude global navigation satellite systems (GNSS) for precise orbit determination of various Low Earth Orbiting (LEO) satellites and make use of the LAGEOS satellites for long-wavelength gravity field modeling or global ground station coordinate determination.

In order to track the LEO orbits we maintain a Satellite Laser Ranging (SLR) ground station which performs highly precise, absolute distance measurements to a variety of satellites in low, mean and high Earth orbits. The SLR station Potsdam is part of the world-wide community of laser stations organized within the International Laser Ranging Service (ILRS). Additionally, we operate a Satellite Receiving Station (SRS) in NyAlesund (Spitzbergen) for near-real-time data reception and monitoring of both the health of the satellites and of the scientific payload from various Earth observing satellites on polar or near-polar orbits (e.g. GRACE, TerraSAR-X or TanDEM-X).

Further on, we evaluate historic and modern altimetry satellite missions in order to investigate sea level trends. For this, we operate and analyze a network of tide gauges on coasts as well as GPS-buoys on the high seas. These permit us to calibrate the altimetry satellite measurements and consequently to record long term changes in sea level.

We design, implement and operate early warning systems, e.g. in Indonesia or Oman, and contribute to global and local hazard monitoring. For this we contribute with GPS-equipped offshore buoys with extended technology and GPS-controlled tide gauges, developed a NRT displacement detection system which captures and measures earthquake-related ground movements using GPS data from various locations over wide areas, and developed small and lightweight river buoys for flood monitoring (e.g. in the Mekong river basin).

Finally, we contribute to the establishment and operation of a hydrometeorological network in Central Asia and to GFZ’s Global Change Observatory at Glaciers in Central Asia by design, implementation and operation of a hydrological monitoring system in this region.

The various projects in our section are divided into four major topics:  

1. Development, operation and analysis of gravity field satellite missions
2. Terrestrial and Airborne Gravimetry
3. Earth System Parameters
4. Geodetic Hazard Monitoring

Details and dedicated projects can be found in the corresponding topic pages.