The 2nd order approximation of measurement noise in optimum linear filtering with coordinate conversion
CHEN Jian chun,DING Lu fei,XU Shao ying (School of Electronics Engineering, Xidian Univ., Xi′an 710071, China)
The linear approximation problem of nonlinear measurement equations in optimum linear filtering with coordinate conversion is discussed. The equivalent noise properties after the coordinate conversion is analyzed by utilizing the polynomial approximation method. The general formulas for calculating the statistical properties of the measurement noise in lower order cases are derived. For the monostatic radar application, the statistical means and covariance matrices in the 1st and 2nd order approximation of the equivalent measurement noise are also given.