Abstract: Based on the problem for velocity attenuation of Flush Air-Data Sensing (FADS) system, a compensation algorithm was developed to compensate for the pneumatic distortion. The principle of velocity measurement by Flush Air Data Sensing (FADS) system based on vector sensor was introduced, the attenuation model was reduced to a second order, state variable model, the comparison of frequency response with both model verifying that the reduced model remains the most dynamic characteristics of the original one. Then, based on the state variable model, the algorithm to compensate for distortion was developed by utilizing minimum estimation theory and Kalman filtering algorithm. The algorithm contains post-flight and real-time algorithms. Both algorithms were verified by simulated and wind tunnel experiment.

Key words: flush air-data sensing (FADS) system, velocity distortion, pneumatic tube, compensate algorithm