Method of Range Estimate Based on Relative Position Information of Image Seeker and INS

The computational method of range estimate is presented to deal with the problem that the accuracy of position is too low to satisfy calculating the time-to-go because the pure INS has worked for long time without GPS. The messengers used by method include sight line angle from image seeker, relative position and altitude from INS. Under typical measuring errors, the influence of sampling frequency on estimation accuracy was analyzed. The engineering application scheme and time-to-go calculation strategy were given. The simulation results show that the accuracy of the range estimate is well enough to be used in engineering.