An Interactive Visualization System for Analyzing Spacecraft Telemetry

Traditionally, the diagnosis of spacecraft anomalies during test and flight is slow and not very thorough due to a limited view of telemetry. The process is an off-line, linear analysis of guessing a root cause and then attempting to verify the guess through identifying and plotting telemetry channels over the appropriate time period. The desire of mission operators and testers is to have a capability to analyze all telemetry channels simultaneously and then be able to freely move through time to cover the entire problem space. Current telemetry display systems, however, only allow an operator to examine on the order of 100 telemetry channels simultaneously from a real-time stream, through a rudimentary playback, or step control of a telemetry archive. This limitation increases the risk that anomalies will be missed and increases the time to determine the real root-cause of the problem. This paper discusses the development and implementation of a visualization system that facilitates a thorough review by enabling an operator to analyze all telemetry data by pattern. This system, called the STEREO autonomy visualizer (SAV) also enables the rapid review of data by using a 'real-time random access' method for viewing real-time and archive telemetry streams. By using the system, STEREO testers have identified bugs that other test review techniques have missed, and decreased the time necessary to perform test review by more than a factor of 5. In addition, use of this system has resulted in a greater understanding of the spacecraft through the visualization of inter-relationships between telemetry channels during faults in flight.