Micromotion Detection of Moving and Spinning Object Based on Rotational Doppler Shift

The detection method of the moving and spinning object is proposed based on rotational Doppler shift in this letter. The wave carrying orbital angular momentum (OAM) is transmitted to illuminate a moving and spinning object, and the echo is modulated by both linear and rotational Doppler effect. According to the OAM spectrum of the transmitted signal and the measured frequency spectrum of the received echo, the linear Doppler shift and the rotational Doppler shift are distinguished, and the object can be detected with high precision. Theoretical and experimental results are provided to validate the effectiveness of the proposed method. This letter can provide an efficient and effective way of moving and spinning object detection in remote sensing.