Abstract

This paper presents the results of an analysis of the feasibility of measuring vibration signatures with near infrared coherent lidar. Quantitative performance predictions have been obtained through the application of the detailed sensor model and realistic measurement scenarios. Using a rigorous formulation of coherent detection, the output of the photodetector was quantified and shown to have the conventional form of a phase-modulated carrier in the presence of Gaussian additive noise. The phase modulation of the carrier is proportional to the time-dependent vibration signature of the illuminated region of the target surface. The carrier phase was also shown to contain an additive stochastic contribution. This contribution, as well as the carrier amplitude, undergo rapid temporal fluctuations that are due to target surface roughness and the apparent target rotation and tilting motion that result during target illumination from a moving sensor platform.

© 1991 Optical Society of America