New radio telescopes for the Geodetic Observatory Wettzell:
Pinpointing Earth's place in space
More precision, higher stability and better data yield - these were the goals that an international group of geodesists set eight years ago for the development of a new radio astronomical measurement method. The group included scientists from the Geodetic Observatory in Wettzell. After five years of construction a key instrument has opened today at Wettzell in the Bavarian Forest: the TWIN radio telescopes.
Each of TWIN telescopes has a diameter of 13.2 meters. They offer several technological advantages:
- As the telescopes can swivel very quickly, the researchers can collect data from significantly more different radio sources.
- A new receiver technology allows recording of data over a broader frequency range. Thus disturbances, e.g., from mobil phones, can be avoided.
- Thanks to the extremely high-precision surface of the mirror the telescopes work very efficiently.
In combination with the observatory's 20-meter radio telescope, the TWIN telescopes will enable the researchers to make observations that were previously not possible. They also work together with other observatories around the world. More TWIN telescopes are planned, for example in Spain, Norway, and Sweden.
The main objective of the measurements is to determine the Earth's rotation and the position of the Earth in space. This is crucial for various applications:
- Without the knowledge of the Earth's position, satellites could not be positioned exactly.
- From their measurements the scientists can create a global coordinate system, which enables observation of changes such as a rise in sea level.
- A precise reference system is also required for GPS navigation and geographic information systems.
40 years Geodetic Observatory Wettzell
The Geodetic Observatory Wettzell is one of the most important institutions of its kind, distinguished especially by the variety of measuring instruments. As a so-called fundamental station it has the task of measuring the position of a reference point in space with high precision over long periods. Worldwide, there are only six other similar observatories.
The Geodetic Observatory traces back to a DFG Collaborative Research Center, on whose initiative the 20-meter radio telescope was built. The collaboration later merged into the permanent Research Group Satellite Geodesy (FSG). It joins activities of the Federal Agency for Cartography and Geodesy (BKG), the German Geodetic Research Institute (DGFI), the Institute for Geodesy and Geo-Information (IGG) of the University of Bonn and two TUM-facilities: the Institute for Astronomical and Physical Geodesy (IAPG) and the Research Facility Satellite Geodesy (FESG).