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Backnang, Germany

Motzigemba M.,TESAT Spacecom
Proceedings of the International Astronautical Congress, IAC | Year: 2013

The trend of a constantly growing demand for high data transfer caused by high performance sensors on Spacecrafts for Earth Observation Missions and the need of fast information update are looking for new solutions. Critical missions will not wait for the next download of LEO data-to-ground stations after next orbit. The combination of Laser Communication between Satellites for high data transmission and the use of a GEO data relay system for reducing the latency time of data refresh, are real game changers. Optical inter-satellite communication has been verified in orbit. Optical links between two LEO satellites achieved bit error rates better than 10"" at a data rate of 5.625 Gbps. Based on that success, DLR and ESA are fostering the realization of a GEO relay service with the PPP Program EDRS, the European data relay system. EDRS will offer by optical communication a data rate of 1.8 Gbps between LEO and GEO Relay. First customer on the LEO part is the GMES Global Monitoring Environmental System with the Sentinel Spacecrafts. The permanent GEO-to-ground link is based on radio frequency communication (Ka-Band @ 26 GHz) for a reliable, commercial service performance through the atmosphere. The improvement of using such a hybrid (Laser communication and RF) system is not only a high data rate service-Fiber in Space - it is offering an extreme reduction of latency time for the information availability with at the same time commercial service conditions. ©2013 by the International Astronautical Federation. All rights reserved. Source


Schaefer S.,University of Kiel | Gregory M.,TESAT Spacecom | Rosenkranz W.,University of Kiel
European Conference on Optical Communication, ECOC | Year: 2015

We present an alternative approach for current homodyne detection systems in optical intersatellite links. Our approach is based on digital frequency offset compensation instead of optical phase-locked loop techniques, in order to achieve a more flexible coherent detection scheme. © 2015 Viajes el Corte Ingles, VECISA. Source


Schaefer S.,University of Kiel | Rosenkranz W.,University of Kiel | Gregory M.,TESAT Spacecom
2015 IEEE International Conference on Space Optical Systems and Applications, ICSOS 2015 | Year: 2015

In order to increase the data rate and lower the power consumption in satellite communication systems, optical laser terminals are an attractive alternative to the conventional RF systems. By using optical coherent detection, high receiver sensitivity as well as full signal recovery is achieved. However, the local oscillator at the receiver requires a carrier recovery system. In order to achieve homodyne detection, an optical phase-locked loop can be used. Each optical PLL structure is fixed to a specific modulation format and its complexity increases with modulation order. Therefore, applying an intradyne detection scheme, where the local laser runs un-synchronized and frequency offset and phase noise compensation is done by digital signal processing after the optical front end, seems to be a possible alternative. We present numerical results for both coherent detection schemes and compare them in terms of receiver sensitivity. © 2015 IEEE. Source


Jaumann G.,TESAT Spacecom
Proceedings of 2015 IEEE International Vacuum Electronics Conference, IVEC 2015 | Year: 2015

TESAT presents an update of the achieved reliability of its TWTAs and MPMs in orbit with data up to the end of the year 2014. Various breakdowns such as SINGLE vs. DUAL units or TWTAs vs. MPMs are presented and discussed. A comparison with the standard reliability analysis based on parts count/stress indicates significantly better reliability in orbit. © 2015 IEEE. Source


Jimenez E.G.,TESAT Spacecom | Jaumann G.,TESAT Spacecom
14th IEEE International Vacuum Electronics Conference, IVEC 2013 - Proceedings | Year: 2013

TESAT presents the achieved reliability of its TWTAs and MPMs in orbit. Various breakdowns such as SINGLE vs. DUAL units or TWTAs vs. MPMs are presented and discussed. A comparison with the standard reliability analysis based on parts count/stress indicates significantly better reliability in orbit. © 2013 IEEE. Source

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