Implementing Subsystem-Level Redundancy within the NOAA Jason Ground System

Abstract

The National Oceanic and Atmospheric Administration (NOAA) Jason Ground System (NJGS) is a consolidated next-generation ground system that will support the simultaneous operation of the OSTM/Jason-2 and Jason-3 ocean surface topography missions. The NJGS will consist of several independent subsystems for spacecraft command and control, telemetry processing, and data archiving and distribution. The existing NOAA Jason-2 Ground System (J2GS) was designed around the concept of subsystem "strings", in which two complete sets of subsystems acted in primary and standby roles. For the NJGS, this concept is replaced with subsystem-level redundancy, in which two or more instances of each subsystem independently provide redundant capabilities. This paper discusses the design elements involved in the provision of a ground system architecture providing redundancy at the subsystem level. The paper focuses on the interaction between primary and standby subsystems and the mechanism through which failover capabilities are provided across the ground system.