The Space-Based Visible Program: Software System and Automation, Data Reduction, & Health and Status
Software System and Automation
The SBV Processing and Operations Control Center (SPOCC) utilizes an intricate, highly complicated software system for processing sensor data. Figure 19 illustrates the architecture of the system. Since the SPOCC operates seven days a week, eight hours a day, the system must be highly automated to minimize costs and ensure reliable and repeatable performance of the SBV sensor. As a result, from the first steps in mission planning to the final transmission of observations to Space Command, human intervention is rarely required. A substantial number of system performance points are monitored for errors, and a robust paging system has been established to bring serious problems to the attention of operators in a timely manner. The paging system, in addition to a health and status information system monitoring the performance of the SBV sensor, gives operators keen insight into the location of a problem, thus allowing for rapid diagnosis and correction. A complement of visual displays and checkpoints allow efficient access to this information [19].
FIGURE 19. SPOCC software architecture. The end-to-end processing of SBV data begins with the Space Control Center (SCC) tasking requests (far left) and progresses through mission planning, command generation, upload to the MSX satellite, data collection, telemetry download, data reduction, and sensor and network monitoring. The system is highly automated to reduce costs.
Data Reduction
Twice every day, the signal-processed data are downloaded from the MSX spacecraft and delivered to the SPOCC at Lincoln Laboratory. The first step in the processing of the data is referred to as decommutation, in which relevant information from the telemetry data stream is extracted and archived in a database. The data-reduction process is responsible for determining the boresight pointing for the sensor, establishing the streak end point locations of the detected RSOs in terms of absolute angles on the sky (right ascension and declination), and correlating the streaks to the catalog of known objects. This process was discussed in detail earlier in this article. As with the entire SPOCC software system, the data-reduction process is automated and is triggered when the decommutation of the telemetry data is complete.
Health and Status
Telemetry data for monitoring the health and status of the SBV sensor are downloaded ten to fifteen times per day, through both the APL and Space Ground Link System stations. The data are automatically processed, archived, and limit checked. The health and status data from every contact are also automatically displayed with appropriate colors to indicate status of any particular subsystem on the instrument. The operator's display uses a standard green-yellow-red monitoring system; the color gray indicates when redundant components are unpowered. The archived data are later processed with trending software to assess long-term behavior [19].