Small perturbations on artificial satellites as an inverse problem

The geocentric motion of a satellite is mathematically simulated by a system of second order ordinary differential equations involving two perturbing functions. The first one represents the second term of the gravitational potential of the Earth and the second is due to the atmospheric drag. Assuming that the solutions of the differential equations and their first derivatives are known from measurements, a stepwise computation of the perturbations is made through a deterministic method. Two examples illustrate our method. In a real case our method should help to design an appropriate maneuver to correct the motion of a satellite.