Object Identification Using Bar Codes Based of LADAR Intensity

Tests of a novel concept for tracking construction components were carried out at the National Institute of Standards and Technology. The approach makes use of laser radar and retro-reflective barcodes attached to manufactured building materials. Tests were conducted for various barcode sizes and spacings through a variety of ranges to a maximum of 40 m. At 40 m, it was possible to infer one byte of information content in a 1D barcode measuring 575 mm (22.6 in.) in length with no special optical processing for a LADAR instrument with an aperture beam diameter of 25 mm and a beam divergence of 2.7 mrad. Simple thresholding post-processing techniques were employed to study the resulting intensity data and to deduce minimum detectable bar gap spacing. These analyses have suggested paths to significant resolution enhancements based on image processing and optical physics simulation techniques.