The characteristic of reference beam laser Doppler signal of solid state surface

Abstract

In the designed reference beam laser Doppler velocimeter (LDV) for the vehicle self-contained navigation system, the reference object is a kind of solid-state surface. This paper expounded the generation mechanism of reference beam laser Doppler signal of this solid-state surface according to the order of the speckle field intensity variation. The expression of reference beam laser Doppler signal intensity of solid-state surface is derived based on the theory of speckle and stochastic process. Results of theory and experiments show that the essence of reference beam laser Doppler signal of solid-state surface is the coherence stack of two speckles. The signal intensity is directly proportional to the diameter of the photosensitive surface of detector and is inversely proportional to the diameter of laser spot on ground.