卷积以差分方程表示的系统的频谱函数和稳态输出的计算-convolution to the differential equation, said the frequency functions and the calculation of the output steady

Hi I like to integrate GPS and INS using kalman filter to predict the position of a vehicle. first of all i like to use GPS sensor readings with kalman filter . I have read lot of research papers for that purpose but I donot know how