Extended Kalman filter based Air Data System (ADS) table update for fighter aircraft

An Air Data System (ADS) plays a key role in stabilization, control and improving performance of modern fighter aircraft. Airdata sensors installed on aircraft generally measures pressure and flow angles in the local flow field using vanes & probes. However, aircraft requires the free stream parameters for flying. Therefore, forward lookup tables in Air Data Computer (ADC) are used to transform local parameters to free stream parameters. Accuracy of free stream parameters depends upon the accuracy of forward lookup tables in Air data computer. These tables are already calibrated using Maximum Likelihood based Estima software. It has been found that ADS tables needs to be updated. Hence, an Extended Kalman filtering (EKF) based technique is proposed to update the existing calibrated ADS tables. In this paper, Vane Alpha, static pressure coefficient and total pressure coefficients tables are updated. Results are generated and comparison is made between Estima based calibrated tables and EKF based updated ADS tables.