Ballistic Missile Launch Position Estimation Based on The First Point Measurement Data of Space Infrared Sensor

The space infrared sensor detects the infrared radiation of the engine tail flame in the active section of the missile, and uses this to determine the launch and motion state of the missile. Although the active period is very short, the position and speed of the entire active period from the first point of discovery to the shutdown point plays a decisive role in determining the launch position, range and landing position of the missile. In particular, the accuracy of the launch point position estimation has a significant impact on the subsequent ballistic parameter identification and trajectory prediction. Therefore, aiming at the difficulty of missile launch position estimation, this paper proposes a launch position estimation method based on the first point measurement data of space infrared sensor. Assuming that the missile is detected by the infrared sensor when it is launched on the ground, at this time, the missile is located on the ellipsoidal surface of the earth, and the intersection of the line of sight ray and the ellipsoidal surface of the earth is the launch position. The positioning equation is derived through the geometric relationship, and the launch position is solved using an iterative algorithm, and the unscented transformation is used to complete the error propagation analysis from measurement error to launch point positioning error. The simulation results show that the method proposed in this paper can accurately estimate the position of the launch position, and the accuracy of the plane in geodesic coordinates can reach 10−4 orders of magnitude with an error of 10−4 rad in the angle measurement of the infrared sensor. At the same time, it is also proved that the positioning error of the launch position is correlated with the measurement error.