For almost exactly 20 years now, the GFZ has been operating a satellite receiving station in Ny-Ålesund on Spitsbergen (78° 55' North, 11° 56' East) to receive data from research satellites in polar orbits. The station is located about one kilometer outside the town of Ny-Ålesund and is only about 1,200 km away from North Pole. It is the northernmost location that can still be reached by researchers using regularly scheduled ships or aircraft.

The first reception of the CHAMP satellite began in Ny-Ålesund 20 years ago via an antenna that was specially converted for this purpose in Germany and then permanently installed on site under a radar dome (radome). It was the starting point for a development that has led to the GFZ today having a powerful receiving station (Fig. 1), which can be used to support satellite missions and projects and services based on them very efficiently. To date, the two antennas have had a total of about 300,000 contacts with satellites carrying scientific instruments. The most important task of the station is currently the reception of the two GRACE follow-on satellites, whose global gravity field measurements are needed for ice mass balances. It acts as the primary receiving station, for which it has qualified both technically and through the many years of reliable operation. With the reception, GFZ furthermore fulfills its obligation towards the project partner NASA/JPL to receive the data of these satellites with main responsibility.

Why a station so far north?

Data from the CHAMP satellite had already been received by a ground station of the German Aerospace Center DLR in Germany since the beginning of the satellite mission in 2000. However, only about four contacts per day were possible because the satellite - due to its low, polar orbit and the rotation of the Earth - could hardly be seen more often in Germany. Thus, the data received in Germany were on average about six hours old. This was sufficient for processing most satellite data.

However, it was not fast enough for data of the so-called GPS radio occultation measurements, from which globally distributed vertical profiles of atmospheric parameters can be derived. These include parameters such as the angle of refraction, temperature or water vapor content of the atmosphere. The radio occultation measurements required for such parameters must be available in near real time so that the GFZ can provide them for weather forecasts, e.g. to the German Weather Service and the English MetOffice. For such services, the data had to be already fully processed and delivered with a maximum delay of three hours after the measurement.

With 15 satellite overflights per day, the data reception in Ny-Ålesund was the most favorable way to make all data usable for weather forecasts in a sufficiently timely manner. Today, the station receives data from the following five satellites: TerraSAR-X (since 2010), Tandem-X (since 2014) and both GRACE Follow-On satellites (since 2018). In addition, there is the reception of the Flying Laptop satellite built by students at the University of Stuttgart (since 2018). Furthermore, the reception of the SAC-C satellites, an Argentine Earth observation mission, from 2010 to 2011 as well as the reception of the predecessor mission GRACE from 2006 to 2017 were important periods in the station's history.

Milestones since 2001

The station's first antenna was installed in 2001 based on collaborations with the Kingsbay Company and the Alfred Wegener Institute, both of which continue to support the station's operations today, and DLR. In addition to CHAMP, the BIRD satellite, which primarily detected fires worldwide through their radiation in the infrared spectrum, was also received for DLR from time to time (2002-2006). The GFZ planned all satellite contacts and modernized the station with new reception technology starting in 2004. In 2005, the GFZ expanded the reception hut, installed a second antenna (Figure 3) and now managed both antennas and all other components of the station with its own know-how. Until 2015, the scientists had to rely on ISDN and a radio link system for data transmission. In the meantime Ny-Ålesund was connected to the European mainland via a fiber optic cable, which also benefited the receiving station through higher data transmission bandwidths and fail-safety.

Current tasks at the station in Ny-Ålesund

The largely automated GFZ receiving station is operated unmanned all year round and is supervised in section 1.2 Global Geomonitoring and Gravity Field. The GFZ colleagues at the Oberpfaffenhofen branch plan all satellite contacts with the station, while the colleagues in Potsdam are mainly involved in technical and administrative tasks as well as remote monitoring and data preprocessing. The software for planning the satellite contacts, the operation of the antennas and receivers and the data processing was developed at GFZ, as well as many solutions for hardware-technical problems. Once a year, the station is serviced on site by the GFZ and gradually modernized. Among other things, work is currently being done to be able to receive higher data rates in additional frequency ranges, in preparation for what will certainly be many new tasks in the future.


Scientific contact:
Dr.-Ing. Carsten Falck
Scientist
Global Geomonitoring and Gravity Field
Telegrafenberg
14473 Potsdam
Phone: +49 331 288-1736
E-Mail: carsten.falck@gfz-potsdam.de

Media contact:
Dr. Uta Deffke
Public and Media Relations
Helmholtz Centre Potsdam
GFZ German Research Centre for Geosciences
Telegrafenberg
14473 Potsdam
Phone: +49 331 288-1049
Email: uta.deffke@gfz-potsdam.de