Airbus Defence and Space

TanDEM-X – observing the Earth in 3D

  • German radar satellite ready for lift-off on 21 June:

  • Final preparations in Baikonur - Airbus Defence and Space satellite "married" with launch vehicle


Baikonur/Berlin, 8 June 2010 – The project to “map the Earth in 3D" is now entering its final preparation stage as the German Earth observation satellite TanDEM-X is readied for launch at the Baikonur Cosmodrome in Kazakhstan. On 21 June, at approximately 04:14:02 CEST, the satellite is due to be launched in to orbit at an altitude of 514 kilometres using a Dnepr launch vehicle. Having moved into the combined operations phase, the launch service provider Kosmotras has assumed responsibility for the satellite hardware from Europe's leading space company Airbus Defence and Space. TanDEM-X is now being integrated into the space head module.


Surveying the Earth in formation flight

The TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) mission demonstrates once again the world-beating German expertise in satellite-based radar technology: the primary mission objective is to record all the Earth's landmasses in 3D, or to be more precise, create a global digital elevation model with unprecedented accuracy. The latest-generation Earth observation satellite will considerably extend scientific and commercial applications in this field. Located just a few hundred metres apart, the two German satellites TanDEM-X and the virtually identical TerraSAR-X, which was launched in 2007, will form the first SAR interferometer in space. TanDEM-X is designed for a service life of at least five years and has a planned, overlapping deployment time with TerraSAR-X of at least three years.


Over this period, the satellite duo will survey the Earth's entire land surface – 150 million square kilometres – in formation flight. Elevation information with an absolute precision of better than two metres is achieved for a 12 metre grid. The specific advantage of satellite-based remote sensing over an aircraft-based solution is that it provides a global, homogeneous terrain model without any discontinuities at country borders or inconsistencies that might arise from different measurement techniques. The use of radar plays a decisive role in this respect since it can be operated independently of weather and lighting conditions.


A wide range of applications

Digital elevation models are fundamental for a wide range of applications: geoscientific disciplines such as hydrology, geology and oceanography call for precise up-to-date information about the properties of the Earth's surface. Applications range from more efficient mining of the Earth's natural resources to optimised crisis deployment planning in disaster areas and for security missions. Digital maps are also a prerequisite for reliable navigation: their accuracy needs to keep pace with the increasing demands placed on global positioning.


The digital terrain model of the Earth will provide Germany with a unique data product in the near future, which can be used in initiatives and programmes such as ZKI (Centre for Satellite Based Crisis Information of the German Aerospace Centre (DLR)), GMES (Global Monitoring for Environment and Security) and GEOSS (Global Earth Observation System of Systems), as well as in security-related co-operation agreements.


Last but not least, commercial customers around the globe are already impatiently awaiting the TanDEM-X elevation model. As soon as the global TanDEM-X elevation model is available in 2013, remote sensing and geoinformation experts from the private sector, government agencies and defence/security establishments will be able to benefit from it in their day-to-day work.



Data processing at DLR in Oberpfaffenhofen – enrichment by Infoterra

A network of three TanDEM-X ground stations (Kiruna/Sweden, Inuvik/Canada and O’Higgins/Antarctica) is required to handle the immense quantities of raw data being transferred. The data pass through three main processing stages. First the data segments transmitted by TanDEM-X to the receiver stations are checked, then the results are evaluated in the processing centre of the German Remote Sensing Data Centre (DFD) run by DLR in Oberpfaffenhofen, and the image data are processed into raw elevation models. In a final step, the Mosaicing and Calibration Processor (MCP) generates the global digital elevation model from the raw elevation models. The related absolute orientation is corrected continent by continent by comparing blocks. The global elevation model dataset will run to 15 terabytes and be available some four years after the launch.


Infoterra GmbH will be solely responsible for customising the elevation model to the needs of commercial users as well as the related global marketing. As part of the data enrichment, Infoterra will process the raw data supplied by the satellite system in accordance with particular customer requirements. This normally involves removing any remaining spikes (peaks or outliers caused by noise) and offsets (can occur due to radar shadow particularly in mountainous terrain) in the data, and editing the representation of expanses of water (ensuring a uniform water level and the right gradient of river courses).



About TanDEM-X 

TanDEM-X is being implemented in a Public-Private Partnership (PPP) between the German Aerospace Centre (DLR) and Airbus Defence and Space GmbH with funds from the German Ministry of Industry and Technology (Bundesministerium für Wirtschaft und Technologie).


The primary goal of the TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) mission is to generate a global digital elevation model. To achieve this, two satellites – TanDEM-X and TerraSAR-X, a satellite of identical construction which has been in orbit since 15 June 2007 – will form the first configurable SAR (Synthetic Aperture Radar) interferometer in space with a separation of only a few hundred metres. A powerful ground segment which is closely interfaced with that of TerraSAR-X completes the TanDEM-X mission. The satellites will fly in formation and operate in parallel for three years to cover the entire surface of the Earth.

DLR is responsible for the scientific exploitation of the TanDEM-X data as well as for planning and implementing the mission, controlling the two satellites and generating the digital elevation model.  Airbus Defence and Space built the satellite and shares in the cost of its development and exploitation. As with TerraSAR-X, the responsibility for marketing the TanDEM-X data commercially lies in the hands of Infoterra GmbH, a subsidiary of Airbus Defence and Space.


About Airbus Defence and Space  

Airbus Defence and Space, a wholly owned subsidiary of AIRBUS Group, is dedicated to providing civil and defence space systems and services. In 2009, Airbus Defence and Space had a turnover of €4.8 billion and more than 15,000 employees in France, Germany, the United Kingdom, Spain and the Netherlands. Its three main areas of activity are Airbus Defence and Space for launchers and orbital infrastructure, Airbus Defence and Space for spacecraft and ground segment and Airbus Defence and Space for the development and provision of secure and commercial satcoms and networks, high security satellite communications equipment, geo-information products and services, and navigation services.


AIRBUS Group is a global leader in aerospace, defence and related services. In 2009, AIRBUS Group generated revenues of €42.8 billion and employed a workforce of more than 119, 000.



About Spot Infoterra products and services

The Spot Infoterra range of products and services is being developed and marketed by the Geo-information division of Airbus Defence and Space. Taking full advantage of the resources and skills offered by its Spot Image and Infoterra subsidiaries, it has become a recognised world leader in the geo-information market.
Spot Infoterra has exclusive access to Spot and TerraSAR-X satellite data, while also calling on a full gamut of space data sources and airborne acquisition capabilities enabling it to offer an unrivalled combination of Earth observation products and services. Its portfolio spans the entire geo-information value chain, offering decision-makers sustainable solutions to increase security, protect the environment and better manage natural resources.


About DLR

DLR is Germany's national research centre for aeronautics and space. Its extensive research and development work in aeronautics, space, transportation and energy is integrated into national and international cooperative ventures. As Germany's Space Agency, the German federal government has given DLR responsibility for the forward planning and implementation of the German space programme as well as international representation of Germany's interests. DLR functions as an umbrella organisation for Germany's largest project sponsor.

Approximately 6,500 people are employed at 13 locations: Cologne (headquarters), Berlin, Bonn, Braunschweig, Bremen, Göttingen, Hamburg, Lampoldshausen, Neustrelitz, Oberpfaffenhofen, Stuttgart, Trauen and Weilheim. DLR also operates offices in Brussels, Paris and Washington, D.C.



Presse contacts:

Daniel Mosely (Airbus Defence and Space GB)                                          Tel. : +44 (0) 1438 778180

Ralph Heinrich (Airbus Defence and Space ALL)                                        Tel. : +49 (0) 89 607 33971

Matthieu Duvelleroy (Airbus Defence and Space FR)                                   Tel. : +33 (0) 1 77 75 80 32

Mathias Pikelj, Airbus Defence and Space (Airbus Defence and Space ALL)                            Tel.: +49 (0) 75 45 8 9123

Francisco Lechón (Airbus Defence and Space ESP)                                   Tel. : +34 91 586 37 41


Mareike Döpke (Infoterra)                                              Tel.: +49 (0)75 45 8 3924

Andreas Schütz (DLR)                                                  Tel.: +49 (0)2203 201 2474




TanDEM-X: Technical data

  • Orbit
  • Type: sun-synchronous
  • Altitude: 514 kilometres
  • Inclination: 97.4 degrees
  • Local time of ascending node: 18:00 hours
  • Repeat cycle: 11 days


  • Satellite
  • Dimensions: 5.0 metres (height) x 2.4 metres (diameter)
  • Launch mass: 1,350 kilograms
  • Power consumption: 730 W (mean figure)
  • Battery capacity: 108 A
  • Service life: 5.5 years (6.5 years for fuels/supplies)


  • Radar
  • Centre frequency: 9.65 GHz
  • Polarisation: Horizontal/horizontal, horizontal/vertical, vertical/horizontal, vertical/vertical
  • Radar incident angle range: 20-55 degrees (15-60 degrees for data recording)
  • Spatial resolution: 1.0 metre (spotlight mode)
  • Sensitivity (noise equivalent sigma nought): -19 dB


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