The invention provides a high-precision trajectory extrapolation method and
system based on an instantaneous
inertial coordinate system, and the method comprises the steps: carrying out the trajectory motion equation modeling based on a geocentric instantaneous
inertial coordinate system according to a
prior information condition obtained through the
passive detection of a
radar, accurately considering the influences of the gravity, the gravity of the J2 item of the earth, the atmospheric damping and the wind; when
radar active detection is carried out, a
radar measurement coordinate
system is converted into a geocentric instantaneous
inertial coordinate system, and
projectile measurement data are obtained; and performing polynomial fitting on the
projectile measurement data and the trajectory motion model, deleting points with large fitting errors in the
projectile measurement data, performing reverse
processing on time and speed, and performing filtering trajectory extrapolation by using the data subjected to the reverse
processing to reduce trajectory extrapolation errors. According to the method, various stresses are accurately modeled, and the influence of Coriolis
inertia force on the motion trail of the projectile is removed by adopting an inertial coordinate
system; abnormal data are deleted through polynomial fitting, the reconnaissance positioning precision is improved by adopting reverse filtering, and the trajectory extrapolation positioning precision is improved.