Abstract: The condition of the roadway with respect to dryness, wetness, or icing is determined, contact-free by way of reflection measurements of light in the infrared range. The reflected light is measured selectively and simultaneously by a receiver in at least two wavelength regions with the wavelength ranges to be determined being in spectral dependence from the surface condition. Formation of a quotient of the detected signals makes possible an unequivocal statement regarding the respective condition of the roadway surface.
November 15, 1991
Date of Patent:
June 8, 1993
TZN Forschungz- und Entwicklungszentrum Unterluss GmbH