Integrated Polar Acquisition and Control Subsystem (IPACs)
The Integrated Polar Acquisition and Control Subsystem (IPACS) real-time system installed at SOCC provides the telemetry processing, spacecraft commanding, and ground system configuration and management functions for the DMSP spacecraft. Real-time telemetry and command processing for multiple spacecraft may occur concurrently on a single Telemetry and Command System (TCS). Each TCS supports up to five processing configurations. A processing configuration is defined as a set of software tasks and data areas that work together to process data for a single spacecraft. A new processing configuration is established when a user signs on from an Operator/Engineer workstation to a specific spacecraft and TCS combination not currently defined. The operator then sets up the processing configuration and establishes datapaths to process telemetry and/or commanding.
The pipeline for telemetry processing on IPACS begins with the Dual Decommutator Command Processor (DDCP). The DDCP receives real-time telemetry from a selected System Communications Unit (SCU) via DOMSAT from the telemetry source site. The DDCP performs frame synchronization, decommutation of the telemetry data, and transmits telemetry to the virtual Communications Controller. The Communications Controller then forwards the data to the telemetry ingest process on the TCS, which performs further processing including limit checking and engineering unit conversion, and forwards the processed telemetry data to the Operator/Engineering workstations for real-time display and monitoring by operations personnel. Stored telemetry is saved on the DDCP and must be transferred to the TCS after the pass is complete.
The pipeline for command processing on IPACS is also via the DDCP. Schedules or Command Procedures (CPs) are started at an Operator/Engineer Workstation, and are executed on the commanding TCS. The individual commands are constructed on the TCS, and then forwarded to the Communications Controller which passes the command to the DDCP. The DDCP translates the commands into the proper format before transmission through the SCU, DOMSAT, and the ARTS Site to the spacecraft.