About the author

Ralph Kahle

After obtaining an aerospace engineering degree from the Technical University of Dresden, Ralph Kahle conducted research as a doctoral student at the DLR Institute of Planetary Research in Berlin on the areas of exposure to near-Earth asteroids and comets, as well as the avoidance of collisions.

Since 2004, he has been a researcher at the German Space Operations Center (GSOC) at DLR Oberpfaffenhofen. He works on flight dynamics systems for satellite missions for communications and Earth observation as well as robotic missions such as the on-orbit servicing mission DEOS.

Ralph Kahle is the flight dynamics engineer for the TerraSAR-X / TanDEM-X Mission. His responsibilities include precise orbit and attitude determination for the satellites, measuring their position relative to one another with millimetric accuracy, the generation of auxiliary products for radar processing, and control of the satellite formation.

Posts from Ralph Kahle

TanDEM-X Blog | 30. July 2013

Formation swapping - Comic about the TanDEM-X mission

An exciting manoeuvre awaits us. In early August (6–8 August 2013), the two TanDEM-X mission satellites will be reversing their formation. Until now, the TanDEM-X satellite has been circling around its twin, TerraSAR-X, in an anti-clockwise direction; after the reversal, it will circle clockwise. This complicated change to the formation in which they have been flying for almost three years is necessary to observe regions that are difficult to image, such as mountain ranges, from the opposite viewing angle. This blog entry takes an unconventional look at the planned change in formation ... read more

TanDEM-X Blog | 15. October 2010 | 4 Comments

The satellites have 'eye contact'

This is the moment we have been anticipating for a long time; TerraSAR-X and TanDEM-X finally have 'eye contact'. The final manoeuvre to adjust the close formation was performed on 13 October. Now, the two satellites are orbiting at a distance of less than 400 metres from one another. read more

TanDEM-X Blog | 20. July 2010

Die 20-Kilometer-Formation ist eingestellt

Mit dem heute nacht durchgeführten Bahnmanöver hat TanDEM-X die noch vom DNEPR-Einschuss kommende Abweichung in der Bahnneigung (Inklination) vollständig korrigiert und seinen Platz in der Formation mit seinem "Zwilling" TerraSAR-X eingenommen. read more

TanDEM-X Blog | 12. July 2010 | 5 Comments

Art in space – or, how to set up a formation

On its launch date, 21 June 2010, roughly 16,000 kilometres separated TanDEM-X from its twin satellite, TerraSAR-X. Now, that distance has shrunk to just 2000 kilometres. The time has come for the relative movement between the two satellites to be slowed down, and for them to be set up for formation flying. To accomplish this, the Flight Dynamics Group at the German Space Operations Center (GSOC) will carry out a total of 10 orbital manoeuvres over the next eight days. read more