The Ground Segment (or ground segment) is the set of infrastructures and applications that enable the management and use of the PRISMA mission. Specifically, it allows to control the satellite, program its operations according to user requests and needs of the satellite, transmit commands, monitor its orbit determining the corrections to be made if necessary, download and archive the acquired data, as well as process them by creating products that are then distributed to the users who requested them.
This complex set of elements, harmonized, allow the satellite's life, and are distributed in two main centers:
• The Satellite Control System (SCS) located at the Fucino Space Centre
• The National Center Multimission (CNM) located at the Geodesy Space Center ASI Matera
At SCC of Fucino Space Centre are located:
• The Mission Control Center (MCC), which collects requests for new user acquisitions, develops the mission plan (the Mission Planning System, MPS) which then transfers them to SCC
• The Satellite Control Centre (SCC), which shall transform the mission plans in remote controls to be sent to the satellite by the antenna in the S-band center, antenna used also to collect telemetry data that the satellite sends periodically to the ground
• The Flight Dynamics System (FDS) which processes the satellite flight data received with the telemetry and determins any orbital corrections
At the National Center Multimission (CNM) of Matera is instead located the reception and processing of the Instrument Data System (IHDS), as well as the interface to the user, for both recording and for requests for images and products.
All interface capabilities to users are made via the web.
They include both the registration requests, requests for new images, image search archival catalog, ordering information for PRISMA products and their distribution to applicants.
The IDHS shall receive user requests and process them according to the type of request.
The images acquired by the satellite are then discharged through the X-band antenna appropriately updated CNM to receive the transmission of the PRISMA satellite.
After receiving the data, the IDHS provides to store them and to generate the products requested by users and to distribute them via the FTP channel of the center.
On specific requests for large data sets, you can also get the sending of media data (eg. Hard Disk).
The satellite communicates with two ground stations located in Italy using two different links, one link is a bidirectional link dedicated to the control and monitoring of the satellite, the other is a high-frequency connection used to download the images generated by the payload.
The phases LEOP and commissioning will be supported by an additional ground station, external to the operating system nominally, to have a control and monitoring of the satellite with a higher frequency.
The high-level architecture of PRISMA system is shown in the following figure:
