• APPLICATION OF A STORAGE AREA NETWORK IN A HIGHRATE TELEMETRY GROUND STATION

      Ozkan, Siragan; Zimmerman, Bryan; Williams, Mike; DeShong, Monica; Avtec Systems, Inc.; Honeywell Technology Solutions, Inc. (International Foundation for Telemetering, 2001-10)
      A traditional Front-end Processor (FEP) with local RAID storage can limit the operational throughput of a high-rate telemetry ground station. The Front-end processor must perform pass processing (frame synchronization, decoding, routing, and storage), post-pass processing (level-zero processing), and tape archiving. A typical fifteen minute high-rate satellite pass can produce data files of 10 to 20 GB. The FEP may require up to 2 hours to perform the post-pass processing and tape archiving functions for these size files. During this time, it is not available to support real-time pass operations. Honeywell faced this problem in the design of the data management system for the DataLynx ä* ground stations. Avtec Systems, Inc. and Honeywell worked together to develop a data management system that utilizes a Storage Area Network (SAN) in conjunction with multiple High-speed Front-end Processors (HSFEP) for Pass Processing (PFEP), multiple HSFEPs for Post-pass Processing (PPFEP), and a dedicated Tape Archive server. A SAN consists of a high-capacity, high-bandwidth shared RAID that is connected to multiple nodes using 1 Gbps Fibre Channel interfaces. All of the HSFEPs as well as the Tape Archive server have direct access to the shared RAID via a Fibre Channel network. The SAN supports simultaneous read/write transfers between the nodes at aggregate rates up to 120 Mbytes/sec. With the Storage Area Network approach, the High-Speed Front-end Processors can quickly transfer the data captured during a pass to the shared RAID for post-processing and tape archiving so that they are available to support another satellite pass. This paper will discuss the architecture of the Storage Area Network and how it optimizes ground station data management in a high-rate environment.
    • A SPACE LINK EXTENSION IMPLEMENTATION FOR INTEGRAL

      Nemesure, Gregg; Safigan, Brian; Avtec Systems, Inc. (International Foundation for Telemetering, 2001-10)
      CCSDS recommendations initially addressed the communication link between spacecraft and ground station. Space Link Extension (SLE) is a set of CCSDS recommended standards for extending the link to control centers, allowing distributed access to space link telecommand and telemetry services. The recommendations encompass the specification of both services and access methods. This paper discusses an implementation of SLE that will be used to provide Forward CLTU service to the upcoming INTEGRAL (International Gamma Ray Astrophysics Laboratory) mission.