Cylindrical coordinate rocket trajectory profiles and line‐of‐sight projective coordinates for tracking ballistic missiles from satellite infrared sensor line‐of‐sight observations

Abstract

In this paper the authors apply the concept of cylindrical coordinate trajectory profiles to the accurate and efficient estimation of the launch parameter state of an intercontinental ballistic missiles from line-of sight observations that are assembled by a pair of geo-stationary satellite infrared sensors. To estimate the four-parameter launch state (geodetic latitude, longitude, direction, time) they introduce the notion of a two-coordinate projective coordinate representation of line-of-sight from observing sensor to observed target instead of the usual two angular coordinates such as local azimuth and elevation. They also introduce the notion of optimally combining launch parameter states, each state estimated from the observations of one of the pair. Finally, they investigate the performance of a nine-component inertial state (position vector, velocity vector, mass, mass rate, drag coefficient) extended Kalman filter that is primed by the optimal state estimate. The extended Kalman filter processes interleaved line-of-sight projective coordinate observations. A numerical experiment is presented with the simulated fly-out of a notional three stage North Korean intercontinental Ballistic Missile as observed by a dual viewing pair of geo-stationary satellite infrared sensors separated by approximately 90 degrees in longitude.