International Ground Segment Department
The escalating number of Earth observation satellites and the breadth and variety of data they deliver pose a technological and operational challenge for the Payload Data Ground Segment. The International Ground Segment department addresses these challenges by focusing on international station locations for satellite data reception and developing engineering EO data processing chains. By sharing infrastructure and responsibilities with the National Ground Segment department, our worldwide stations provide independent and global access to critical national and European primary mission data.
The National Ground Segment primarily manages a multi-antenna site for various missions in Neustrelitz, while the International Ground Segment oversees a variety of station locations, including remote polar antenna sites in O’Higgins, Antarctica, and Inuvik in the Arctic. The department is tasked with designing, establishing, maintaining, and operating large antenna systems in extremely harsh polar environments to receive satellite data for a multitude of Earth observation missions. To ensure reliable and fully automated station operations at unmanned locations worldwide, we have developed our own satellite ground station control and monitoring system.
Additionally, we develop and operate mission-specific processing systems where the received payload data is transferred to various processing systems and converted into products of varying content depth (levels). With different focal points, these developments and comprehensive engineering tasks are also shared with the National Ground Segment department. This combination of infrastructure and knowledge results in our strong and internationally recognized competence in effective and reliable data access and data processing in the context of a PDGS or for geoscientific research.
Satellite EO data processing currently faces the challenge of managing very high data volumes along with a significant increase in processing complexity. Examples of this include the TanDEM-X bi-static processing and the interdependent product variety of Sentinel-5P data, both of which we developed and operate under the PDGS umbrella. To address these demands, we developed a cloud-computing-compatible workflow and resource management system for EO data processing, named prosEO, as an open-source project. We further expanded the DFD in-house GeoFarm private cloud facility into a highly available and scalable data processing infrastructure for multi-mission operations.
In the PDGS, we have undertaken tangible activities for major national and ESA/EU Copernicus missions in recent years. Noteworthy is our participation in Tandem-L and HRWS mission studies, which accelerated our developments in the area of very high data rate downlink and the conceptual design of a mission exploitation platform. This is a prime example of major IT trends influencing our new PDGS developments, such as hardware virtualization and service-oriented architecture. Previously, IT hardware properties were included and set up in dedicated mission-specific engineering processes. Now, hardware virtualization to a certain degree makes applications independent of the actual hardware used. This approach, already common for virtual machines in computing centers, is increasingly being applied to ground station hardware. We have developed concepts and software to apply this approach for nearly all hardware resources in PDGS – for ground stations as well as computing platforms.
Service-oriented architecture does for software what virtualization does for hardware. Software functions provided as services can be reused in different contexts by different applications, making users independent of the actual software implementation. The use of virtualized hardware via a specific service may also cross organizational boundaries. In this context, we are significantly contributing to the development of the terrabyte project, our future EO science big data computing platform, in cooperation with the Leibniz Supercomputing Centre (LRZ) in Garching. The department's cross-cutting activities are highly interconnected and follow the data chain from satellite to ground, via processing of the data and product delivery to users. Combined with the fact that the systems developed and integrated in the department are also operated in the department, the team structure is organized according to this systematics.