Simulation of Reentry Detection by Estimated Atmospheric Component

In this paper, the theoretical atmospheric reentry criterion for space objects is verified by simulation. Atmospheric reentry refers to the return of space objects into Earth's atmosphere. These space objects are tracked by radar using LFM waveforms. The re-entry criterion determines the moment of transition to algorithms that track space objects in the atmosphere. The Kalman filters are applied to estimate the motion parameters of space objects moving along different trajectories corresponding to motion in and above the atmosphere. The difference between these trajectories is caused by the different set of forces acting on the space objects, so the different motion models are used in the filtering procedure. The residual of the Kalman filter is used in the simulation to numerically estimate the height of atmospheric reentry. This residual is the difference between the measured range and the predicted range of the above-atmosphere filter, which tracks space objects moving above the atmosphere. The moment when the residual becomes significant is interpreted as atmospheric reentry which leads to a change in the motion model: from the above atmospheric model to the atmospheric model.