Real-Time Attitude Estimation Bias Correction for Scanning Surveillance Sensors

Knowledge of the orientation of a scanning sensor's line-of-sight coordinate system can be enhanced by observing fiducial objects in the scan field of regard. The known locations of these objects can be used to estimate biases in the line-of-sight attitude estimator. However, significant time delays in identifying the fiducial objects and restrictions on the timely application of estimated corrections can cause severe ringing in the observation errors. A time delay mitigation scheme that significantly reduces this ringing and speeds up the convergence of the estimate of the orientation of the line-of-sight coordinate system is discussed.