December 21, 2023

Christmas markets as seen by TerraSAR-X and TanDEM-X

  • Images acquired by the German radar satellites TerraSAR-X and TanDEM-X show Christmas markets around the world.
  • For this purpose, two or more images were taken from the same angle using Synthetic Aperture Radar (SAR) technology.
  • The changes in land use outside the Christmas market season are clearly recognisable.
  • TerraSAR-X and TanDEM-X have been providing high-resolution 2D and 3D images since 2007 and 2010 respectively, regardless of weather conditions and daylight.
  • Focus: Space, Earth observation

To mark the end of the year, the TerraSAR-X and TanDEM-X satellites operated by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) embarked on a search for Christmas markets around the world. The result – fascinating radar images that take the viewer into winding alleyways or bring the special atmosphere of Christmas markets by the sea a little closer.

In Nuremberg, for example, the Christkind opens the 'little town of wood and cloth' on the Friday before the first Advent each year from the balcony of the Frauenkirche. Unfortunately, neither cloth nor wood are materials that can be observed particularly well with radar satellites. For this reason – and due to the small size of the market stands – they are not clearly visible in the pictures. What you can recognise very well, however, are changes. These result partly from the crowds of people present during the opening hours of the Christmas market, but also from the comparison of images taken before the market was set up with images taken during the running of the market.

The radar satellites TerraSAR-X and TanDEM-X have each produced two or more SAR images from the same angle.The difference between the images reveals changes, which are shown in orange. Areas such as parks, trees or lawns that have only changed slightly between the images are shown in green. Fixed structures such as buildings or streets are shown in blue.

We hope you enjoy the virtual tour and wish you a wonderful holiday season!

About the mission

The TerraSAR-X and TanDEM-X missions were implemented on behalf of the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR), with funding from the Federal Ministry for Economic Affairs and Climate Action (Bundesministerium für Wirtschaft und Klimaschutz; BMWK). They are the first German satellites to have been created as part of a Public-Private Partnership (PPP) between DLR and Airbus Defence and Space GmbH. 

DLR is responsible for the construction and operation of the ground segment as well as for the scientific use of the data and its distribution to external researchers worldwide. Airbus Defence and Space GmbH contributed to the costs of the development, construction and launching of the satellites. The Geo-Intelligence programme line at Airbus Defence and Space is responsible for the commercial marketing of the data. Since 2016, the project has continued under a follow-on agreement with Airbus.

TerraSAR-X and TanDEM-X are particularly suitable for observing changes on the Earth's surface. They are capable of capturing 2D and 3D images with high resolution and independent of weather conditions and daylight. Both satellites provide high-quality radar images for a wide range of applications in the scientific, commercial and security sectors.


Markus Bachmann

Ger­man Aerospace Cen­ter (DLR)
Mi­crowaves and Radar In­sti­tute
Münchener Straße 20, 82234 Weßling

Michael Müller

German Aerospace Center (DLR)
Corporate Communications
Linder Höhe, 51147 Cologne
Tel: +49 2203 601-3717