Determining inertial errors from navigation-in-place data

To validate the self-calibration performance of a missile system's inertial navigation system (INS), an inertial error estimator (IEE) and a calibration procedure were developed and tested. The IEE was developed using a least squares fit of navigation-in-place data to calculate the accelerometer biases, the gyroscope biases, and the axis misalignments. It was found that the estimation error due to highly correlated regression functions decreases with navigation time. A tradeoff study was performed to select the optimum navigation-in-place time allowed for determining the estimation of the inertial errors. Once the optimum navigation time was determined, an INS calibration procedure incorporating the IEE was developed. The calibration procedure was validated by applying corrections for the inertial errors to the INS, and then navigating in place to show a reduced position error profile. Test results showing the outcome of the INS calibration procedure are included.<>