Development of a route segementation procedure using predicted layer thicknesses from radar measurements

Massive quantities of data can be accumulated very quickly with current ground penetrating radar equipment and software (e.g., approximately 1 trace every 2 feet at 35 mph). Depending on the size of a given network, and the frequency of sampling, the processing of radar data can yield a voluminous amount of layer thickness information on the network surveyed. For example, given a sampling rate of 1 trace every 2 feet and a 100-mile network, layer thickness estimates for about 264,000 points along the network can be generated for each lane surveyed. To be useful for pavement management applications, a post-processing stage is important during which time, the given network is subdivided into homogeneous sections or segments based on the radar predictions. A computerized procedure for route segmentation in the post-processing stage is presented in this paper. The program developed uses the cumulative difference approach as the basis for delineation. In the procedure, the cumulative difference method is successively applied until no further delineations are possible based on userspecified criteria for minimum section length and minimum difference between means of adjacent segments. A number of other criteria are also used. The program has been tested and verified using pavement sections with known changes in pavement structure with satisfactory results.