Patent ID: 7248206

Claim:
A method for real-time target tracking and sensor angular alignment estimation and amelioration for targets having known acceleration, said method comprising the steps of: measuring with at least one sensor at least one of (a) line-of-sight or (b) position of the target, to produce target track state measurement information for each sensor, which target track state information includes unwanted angular bias errors attributable to each sensor; filtering said target track state measurement information with a filter to produce updated target track state information with reduced angular bias errors by correcting the target track state measurements for known alignment bias and for previously determined estimated sensor alignment biases, to thereby produce corrected measurements; at least when corrected measurements are received, producing estimated target state derivative vectors by updating the filter time reference to the measurement time to produce propagated state derivative vectors; determining the Jacobian of the state dynamics equation providing for observability into the sensor alignment bias through at least gravitational and coriolis forces; from said Jacobian of the state dynamics equation, propagating the target state transition matrix and the target error covariance matrix; if a measurement is not available, repeating said steps of producing estimated target state derivative vectors, determining the Jacobean, and propagating the target state transition and target error covariance matrices; if a measurement is available, calculating the Kalman gain matrix using a measurement matrix and the error covariance matrix; updating the state vector to produce an updated state vector and estimated sensor alignment biases; updating said covariance measurement to produce an updated covariance measurement; and transforming said state vector and covariance measurements to an estimated stable space frame to produce said updated target track state information with reduced angular bias errors; and utilizing said updated target track state information as indicative of the target.