Tracking filter and prediction for non-ballistic target HTV-2 in near space

Recently, different countries have made rapid developments in the field of near space hypersonic vehicles such as the successful hypersonic vehicle flight tests of X-51A and Hypersonic Technology Vehicle-2(HTV-2). HTV-2 often actuates some nonballistic maneuvers while flying for a long time with high speed and large lift-to-drag ratio. Its motion trajectory is sometimes characterized by "hopping", meaning it is quite difficult to estimate and predict its trajectory. This paper gives an overview of existing problems in the tracking and prediction of hypersonic aircrafts firstly. Then a tracking filter for HTV-2 trajectory is presented. It uses Kalman filter algorithm to make an estimation of three-axis target position. Numerical simulation results show that the estimation accuracy of Kalman filtering algorithm is within allowed range. So the filter has certain reference significance in practical applications.