International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Low Earth Orbit Terminal (LEO-T) developed by AlliedSignal for NASA Wallops is a fully autonomous satellite tracking system which provides a reliable, high quality, satellite data collection and dissemination service. The procurement was initiated by NASA, in an effort to provide more tracking capacity with a decreasing budget. A large mission set of NASA satellites in the next decade will not require the performance of existing large aperture systems. NASA is planning to use the larger aperture antennas to only support those missions needing the higher performance. The remainder of the missions will be supported with the smaller LEO-Ts, which are smaller, significantly less expensive, and fully automated. The procurement is also an attempt at a first step towards fostering commercialization and privatization of small station acquisition and services. The system design features a modular architecture to simplify integration and to support affordable future expansion. This paper begins with a brief summary of the LEO-T program, then provides the design details and capabilities of the LEO-T system.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / 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.