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E-4.3 Attitude Ephemeris and Events Generation

Figure E-4 contains the DFD associated with Generate Attitude Ephemeris and Events. Three ovals represent applications associated with predicting and reconstructing key mission events, which are based on results from Determine Attitude and associated sensor attributes (e.g., field-of-view).

Generate Attitude Ephemeris - This function propagates the attitude ephemeris forward in time and stores a series of attitude states in the Attitude Ephemeris data store.

Generate Sensor Event Predictions - This process uses data regarding a spacecraft's orbit, attitude, and sensors as well as data regarding the Earth and celestial bodies to generate sensor support (i.e., tasking) intervals within a selectable time span. Results are passed to Mission Planning.

Generate Sensor SLP Intrusion Predictions - This function applies data regarding a spacecraft's orbit, attitude, and sensors as well as data regarding the Earth and celestial bodies to predict intervals of sensor intrusion (within a selectable time span) by celestial bodies (e.g., sun or moon).

Generate Transmission Angle and Data Rate Switch Intervals - This process extracts data regarding a spacecraft's orbit, attitude, and antenna pattern as well as data regarding the Earth's position to generate antenna and data rate switch intervals relative to a given ground station. Results are passed to Mission Planning for inclusion in the Contact Support Plan.

Diagnose Attitude Condition - This process uses the Anomaly Resolution knowledge base, the Orbit Ephemeris data store, and the Attitude Ephemeris data store to predict any future attitude anomalies. If needed, an attitude maintenance activity is requested through the Timeline data store.

Figure E-4. Generate Attitude Ephemeris and Events data flow diagram.