ROAD SURFACE STATE DETECTION DEVICE AND ROAD SURFACE STATE DETECTION METHOD

摘要

A radio waves receiving unit 1 receives horizontally polarized waves and vertically polarized waves of radio waves radiated from an object at a radiation angle. An image generation unit 2 generates a horizontally polarized waves image and a vertically polarized waves image based on the horizontally polarized waves and the vertically polarized waves, respectively. A polarization ratio calculation unit 3 calculates, for each radiation angle, a polarization ratio which is a ratio of intensity of the horizontally polarized waves to the vertically polarized waves based on the horizontally polarized waves image and the vertically polarized waves image. A refractive index calculation unit 6 calculates a refractive index of the object based on a change between polarization ratios of two different radiation angles. A road surface condition recognition unit 8 recognizes a condition of a road surface based on the refractive index.