Based on fuzzy logic control adaptive bandwidth PLL design is presented for the problem of tracking poor stability and low accuracy when a certain type of radar tracking dynamic spacecraft. This method is mainly through fuzzy logic controller, adaptive level is determined by control rule of input respectively, and the outputs of rules are weighted combined to control the coefficient of loop filter, thus adjusting automatically the loop bandwidth, and enhancing the tracking stability of radar equipment and improving ranging accuracy. The simulation results show that the fuzzy logic control adaptive bandwidth PLL has higher tracking stability and accuracy.

The variation rules of middle and high level atmosphere affected by sun activity are analyzed, and atmosphere resistance perturbation acceleration models of spacecraft orbit are deduced. Atmosphere resistance perturbation is simulated by STK, and the parameters of spacecraft orbit affected by atmosphere resistance are got at different situation of sun activity. Finally, the life of spacecraft orbit is calculated.