eROSITA ground operations

eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the primary instrument on-board the Russian/German "Spectrum-Roentgen-Gamma" (SRG) mission. It will perform the first all-sky imaging X-ray survey in the medium X-ray energy band. eROSITA is currently awaiting its launch from Baikonur in early 2019 into an L2 halo orbit. Preparations for eROSITA ground operations have been under way in parallel with the hardware development of the eROSITA telescope, comprising the areas mission planning, telescope operation and data reception, the operation of a data processing pipeline, and the creation of tools for data access and interactive data analysis. eROSITA mission: After a brief calibration and performance verification phase eROSITA will perform a four-year all-sky survey fully covering the sky eight times, which will be followed by several years of dedicated observations of interesting objects. Two ground antennas in Russia (near Moscow and in Siberia) will be available to provide several hours of daily ground contact for commanding and for data reception. eROSITA data rights will be equally divided between the Russian and German partners. Operation and data centers will exist at Max-Planck-Institut für extraterrestrische Physics (MPE) in Garching, Germany and at the Russian Space Research Institute (IKI) in Moscow. Interfaces and procedures for mission planning, telescope operation and data exchange are closely coordinated between both sites. Mission planning and operation: Based on orbit simulations provided by the Russian side, a software environment for optimizing the desired sky coverage and observing efficiency while fulfilling visibility and solar constraints was set up. Agreed upon observing timelines will be converted to eROSITA and SRG command sequences fed to the Russian ground station for up-linking. MPE personnel will be on site either in Moscow or at MPE in Garching during each ground contact to conduct ondemand commanding and to assess instrument health and data quality. Data analysis pipeline and interactive data analysis: The eROSITA data processing pipeline consists of modules for data ingestion, event calibration, exposure calculation, source detection, and the creation of high-level source specific data products. It will be operated at MPE on a daily basis after each ground contact. A subset of the software tasks comprising the data analysis pipeline also functions as interactive data analysis tools. These can be grouped into tasks for X-ray event calibration, selection and binning, exposure, background and sensitivity map creation and for source detection. Data products are provided in a standards compliant FITS format for use with well-known high-level X-ray data analysis tools. A Web based graphical source catalog and data products viewer will allow easy data browsing. Since mid-2014 the interactive eROSITA data analysis package is available to the eROSITA user community, permitting the analysis of simulated eROSITA datasets, created by a sophisticated X-ray modeling and simulation tool.