Research on Accurate Measurement Method of TACAN Azimuth Based on Curve Fitting

Because the method of azimuth measurement by the zero point in TACAN has the problems such as large error and weak noise immunity, an accurate measurement method based on sine wave curve-fitting is discussed according to the character of TACAN signal. Least square algorithm is used to estimate parameters of the curve and the error between the signal and the fitted curve is calculated. The measured signal´s quality factor which can confirm the reliability of the measured value is defined. Simulations were performed under different SNR to compare the performance between traditional method and curvefitting method and analyze the quality factor´s variance when the measured signal has a distortion. The simulation results have proved that curve-fitting method will evidently improve the precision of measurement and the signal´ noise immunity. The quality factor reflects the signal´s distortion well.