CG-1280 Rev. N 09/13 - General Dynamics SATCOM Technologies

Overview2.10 Tracking FunctionsThe 7200 ACU allows a user to configure up to 50 targets for establishment oftarget-specific databases (refer to Section 5.8.2.6). The following tracking modesare available:• Move to longitude (refer to Section 2.9.1)• Move to look angles (refer to Section 2.9.2)• Orbit Prediction Tracking (OPT)• Star tracking (refer to Section 2.9.4)• Intelsat 11-element (IESS-412) (refer to Section 2.9.5)• Orbital Element Track (Optional) (refer to Section 2.9.6)2.10.1 Orbit Prediction TrackingThe OPT system provides exceptional short-term and long-term pointing capabilitiesby combining orbital mechanics with modern modeling and error analysis techniques.Orbital mechanics are used to provide a model of the satellite and earth's surfacemotion. The modeling and error analysis takes pointing data collected in Steptrackoperations and finds the satellite orbital parameters and systematic errors caused bythe mechanical structure which provide the best least squares solution. The orbitalparameters and systematic errors are then fed back through the orbital mechanicsmodels to determine antenna look angles at any future point in time. The modelsaccurately match the "real world" and provide excellent real world results. (Refer toSection 3.1).2-31