Angle, elevation, PRF, and illumination in radar microDoppler for security applications

We discovered several important characteristics that should be considered in the development of radar systems for the measurement of human micro-Doppler. First, radar which illuminates parts of the human body separately is capable of distinguishing more structure in the micro-Doppler because of the decreased interference from other body parts. Second, a PRF of even as low as 400 Hz is sufficient for measuring micro-Doppler, though higher is recommended. Third, the direction of motion of the target can be critical, but a higher elevation angle can be used to avoid the difficulties experienced when the motion of the targets is perpendicular to the beam of the radar.