ADVANCED COMMUNICATIONS SOLUTIONS FOR THE NEXT GENERATION OF EARTH OBSERVATION SATELLITES

Advanced Communications Solutions for the Next Generation of Earth Observation Satellites

O.Koudelka, F.Teschl, W.Gappmair
Graz University of Technology, Austria
koudelka@tugraz.at, franz.teschl@tugraz.at, gappmair@tugraz.at
M.Kerr, S.Tonetti, S.Cornara
DEIMOS Space, Spain
murray.kerr@deimos-space.com, stefania.tonetti@deimos-space.com,
stefania.cornara@deimos-space.com

Abstract

EO- ALERT is a European Commission H2020 project coordinated by Deimos Space. Partners are DEIMOS Imaging, OHB Italia, DLR, Politecnico di Torino and TU Graz. The goals of the project are the definition and development of the next-generation Earth Observation (EO) data processing chain. In contrast to conventional EO satellites, key elements of EO data processing is taking place on board using advanced avionics with the aim of delivering the EO product to the End Users with very low latency. Applications considered in the project are ship detection and severe weather monitoring and nowcasting. An important element is the communications subsystem which has to deliver bulk data and alerts generated on board with high data rates and minimum latency. The latency requirements for global data delivery are quite stringent: 30 minutes for bulk data and max. 5 minutes for alerts. Since the raw synthetic aperture radar (SAR) and optical images are large (466 and 200 MB each) high-speed links are necessary. The alerts are small in comparison (10 kB), but during an orbit up to 900 alerts can be generated resulting in a data volume of 9 MB.
In the framework of EO-ALERT TU Graz is investigating a variety of efficient solutions for data delivery on a global scale meeting the latency and throughput requirements. Ka-band direct-to-ground links with data rates up to 1.8 Gbit/s are the baseline for bulk data delivery. Alternatively, new developments in the area of optical terminals both for direct-to-ground communications using optical ground stations as well as optical data relay links to the European Data Relay Satellite (EDRS) system have been investigated.