Amplitude-Modulated Laser Radar for Range and Speed Measurement in Car Applications

Doppler laser radar can improve the precision of speed measurement by about two orders of magnitude compared with time-of-flight range finders, which obtain target speeds by range differentiation. However, in a car environment, the usage of traditional Doppler laser radar schemes is limited, because they do not satisfy the requirement of simultaneously measuring the target range together with speed with high precision. First, in this paper, we describe a new in-car laser radar system and show a new modulation scheme that enables the in-car laser radar to simultaneously measure the target range and speed with high precision. Then, we perform simulations and experiments to verify the accuracy of the proposed method. In the Appendix, a brief review of current widely used laser radar schemes is given. The limitations of these schemes to their employment in car applications are also discussed.