Fault detection and fault isolation in the ground station

The satellite ground station environment is one in which the availability of the equipment is normally paramount. Satellite contacts may be scheduled at any time and the data being down-linked may be irreplaceable if the equipment in the ground station is not available to receive it. The satellite may not be able to carry out its mission if necessary data is not up-linked when needed because of equipment outage. Availability is a function of mean time between failures (MTBF) and mean time to restore (MTTR). In many cases, the MTBF is addressed by installing equipment built with highly reliable parts, while MTTR is minimized by the inclusion of redundant equipment in the architecture. If a failure does occur, the redundant equipment can be brought into action only after the failure has been detected, isolated, and reported. In some cases, this is not straight forward. The interaction of multiple pieces of equipment may make a simple diagnosis impossible without further investigation. This paper presents an approach to fault detection and fault isolation (FDFI) which can increase the availability of the equipment by reducing the delay in the discovery and isolation of a fault. The approach can be implemented, in full or in part, based upon a cost benefit trade. If the data is not time critical, or if the procurement budget is constrained, a subset of the techniques and the features discussed may be implemented. Program unique analysis shows the best combination for each application.