Investigation on the rotating speed estimation of spinning objects based on the rotational Doppler effect

Rotational Doppler effect is an important phenomenon during the detection by vortex electromagnetic wave carrying orbital angular momentum. Compared with traditional plane wave, rotational enables to detect spin motion along rotation axis of targets. However, there still are blind zones when integer momentum beams used specific spinning objects. To expand application scope scheme based on effect, time-frequency analysis, this paper researches estimation method for speed objects under normal incidence and oblique fractional beams. Firstly, ideal scattering point model, echo models derived respectively, as well theoretical curves. Then take 3-D practical object example, its graph achieved short-time Fourier transform. The ridge fluctuation period extracted from graph, so estimate results prove that, can be effectively, whether or incidence. It overcome zone beams, has better applicability in detecting motion.