Modeling and analysis of speckle effects for velocity measurements with Self-Mixing Laser Diode Sensors

This paper deals with the optimization of laser diode self mixing sensors for velocity measurements when self-mixing signals are corrupted by the speckle phenomenon, a process of a random nature due to the surface roughness of the moving target. A new behavioral model is presented and used to design and compare real time and optimal signal processing algorithms for Doppler frequency estimations. Finally, experimental results, obtained in the context of automotive applications, validate the proposed model in measuring car velocities.