A system for inspecting a railroad track bed, including the railroad track, to be mounted on a vehicle for movement along the railroad track, wherein the system comprises: at least one light generator positionable adjacent the railroad track for projecting a beam of light across the railroad track bed; at least one optical receiver, wherein the at least one optical receiver comprises a digital camera positionable adjacent the railroad track for receiving at least a portion of the light reflected from the railroad track bed and for generating a plurality of images representative of the profile of at least a portion of the railroad track bed; characterized in that the optical receiver comprises a band pass filter allowing substantially only the wavelength of the beam of light to be captured in the plurality of images; and at least one processor configured to analyze the plurality of images and to determine one or more physical characteristics of the said portion of the railroad track bed, the processor including an algorithm for detecting a misaligned or sunken tie plate of the railroad track bed, the algorithm comprising the steps of: (a) analyzing a frame of the plurality of images, the frame comprising a region of interest; (b) determining whether the region of interest contains a tie plate; (c) if a tie plate is present, determining a crosstie contour and a tie plate contour; (d) comparing an orientation of the crosstie contour and an orientation of the tie plate contour; and (e) determining whether the tie plate is misaligned or sunken based upon the comparison. at least one light generator positionable adjacent the railroad track for projecting a beam of light across the railroad track bed; at least one optical receiver, wherein the at least one optical receiver comprises a digital camera positionable adjacent the railroad track for receiving at least a portion of the light reflected from the railroad track bed and for generating a plurality of images representative of the profile of at least a portion of the railroad track bed; the optical receiver comprises a band pass filter allowing substantially only the wavelength of the beam of light to be captured in the plurality of images; and at least one processor configured to analyze the plurality of images and to determine one or more physical characteristics of the said portion of the railroad track bed, the processor including an algorithm for detecting a misaligned or sunken tie plate of the railroad track bed, the algorithm comprising the steps of: (a) analyzing a frame of the plurality of images, the frame comprising a region of interest; (b) determining whether the region of interest contains a tie plate; (c) if a tie plate is present, determining a crosstie contour and a tie plate contour; (d) comparing an orientation of the crosstie contour and an orientation of the tie plate contour; and (e) determining whether the tie plate is misaligned or sunken based upon the comparison. (a) analyzing a frame of the plurality of images, the frame comprising a region of interest; (b) determining whether the region of interest contains a tie plate; (c) if a tie plate is present, determining a crosstie contour and a tie plate contour; (d) comparing an orientation of the crosstie contour and an orientation of the tie plate contour; and (e) determining whether the tie plate is misaligned or sunken based upon the comparison.