The CryoSat ground segment is currently organised around a single ESA ground station, located in Kiruna in northern Sweden. This is where contact is established with the satellite, for about 10 minutes 11 times per day, during which commands are sent to the satellite, and data downloaded over an X-band microwave link.
Mission planning, however, is performed in ESA-ESRIN for what concerns the payload part (mainly the instrument activity planning) and in ESA-ESOC for what concerns the platform part (mainly orbit maintenance through manoeuvres). The detail plan is uploaded weekly to the satellite from Kiruna-Salmijarvi.
It is worth noting that the CryoSat instrument activity is mostly repetitive, and is based on ground topology (ice boundaries evolving through the year) with a few specific user demands for Near Real Time applications, therefore it is subject to periodic modifications which follow the seasonal cycle.
CryoSat ground segment
The large amount of data received from the payload, and in particular from the altimeter, is processed at Kiruna-Esrange. Data products at Level-1b (radar echoes geo-located and corrected for instrument features) and Level-2 (ground elevation and ice freeboard, corrected for atmospheric and geo-physical effects) are produced by ESA systematically, based on the repetitive data acquisition planned above. There is no 'on-demand' data processing in the routine data production; however, provision is made for troubleshooting needs.
All external auxiliary data needed for the data processing, and in particular the Precise Orbit data is received from the SSALTO centre operated by CNES in Toulouse, with one exception - dynamic sea-ice concentration which is received from UCL in London.
Data are routinely distributed to users via the internet. Use of high-speed infrastructure and network services are also used to the maximum extent feasible.
Data are also sent to CNES who is acting as the Long Term Archive for all mission data.
An important aspect of the CryoSat ground segment is that it is designed for operations with a low level of manpower. Furthermore, remote operations and troubleshooting can be performed on all systems located in Kiruna.