RCS of human being physiological movements in the 1–10GHz bandwidth: Theory, simulation and measurements

Analysis of radar backscattering of moving objects is usually performed by Fourier spectral analysis, allowing the discrimination of signals located at different Doppler frequencies. This approach applies in the hypotheses that, during the observation time, the targets move with uniform radial velocity and their range changes by several wavelengths. This is not always verified, e.g. for physiological internal movements when observed at low frequencies. This paper presents a theoretical model to represent the radar backscattering of targets having sub-wavelength motion. Alternatives to the Fourier approach are discussed, matching the model with experimental data.