EUVE Telemetry Processing and Filtering for Autonomous Satellite Instrument Monitoring

Abstract

A strategy for addressing the complexity of problem identification and notification by autonomous telemetry monitoring software is discussed. The Extreme Ultraviolet Explorer (EUVE) satellite's science operations center (ESOC) is completing a transition to autonomous operations. Originally staffed by two people, twenty-four hours every day, the ESOC is nearing the end of a phased transition to unstaffed monitoring of the science payload health. To develop criteria for the implementation of autonomous operations we first identified and analyzed potential risk areas. These risk areas were then considered in light of a fully staffed operations model, and in several reduced staffing models. By understanding the accepted risk in the nominal, fully staffed model, we could define what criteria to use in comparing the effectiveness of reduced staff models. The state of the scientific instrument package for EUVE is evaluated by a rule-based telemetry processing software package. In the fully automated implementation, anomalous states are characterized in three tiers: critical to immediate instrument health and safety, non-critical to immediate instrument health and safety, and affecting science data only. Each state requires specific action on the part of the engineering staff, and the response time is determined by the tier. The strategy for implementing this prioritized, autonomous instrument monitoring and paging system is presented. We have experienced a variety of problems in our implementation of this strategy, many of which we have overcome. Problems addressed include: dealing with data dropouts, determining if instrument knowledge is current, reducing the number of times personnel are paged for a single problem, prohibiting redundant notification of known problems, delaying notification of problems for instrument states that do not jeopardize the immediate health of the instrument, assuring a response to problems in a timely manner by engineering staff, and communicating problems and response status among responsible personnel.