Research on direct position determination method based on interferometer system

The Direct Position Determination (DPD) method can obtain the motion state information of the target directly from the signal received by the base station without measuring the positioning parameters in the first place, so it can provide more accurate positioning estimation. In order to solve the problem that the interferometer system’s positioning error increases or even fails to locate when the signal-to-noise ratio is low, a DPD method based on the interferometer system is proposed. Based on the information of time difference and phase difference, a cost function was constructed based on the principle of maximum likelihood estimation. Simulation analysis shows that the proposed positioning method is also effective under the condition of low signal-to-noise ratio.