Test courses are monitored at the U. S. Army Aberdeen Test Center (ATC) on a monthly basis and are altered as required to maintain a "constant" roughness. The monitoring process consists of a jury ride and analysis of data acquired using an instrumented, light wheeled vehicle. The surface profiles of test courses at ATC are also measured on a monthly basis using a profilometer. A series of displacement and angular measurements are made. These are used to compute surface roughness as a function of distance traveled over the test course. This article proposes two techniques for determining vehicle sensitivity to changes in test-course roughness (vehicle-dependent ride quality and vehicle-independent fatigue damage spectrum) and, thus, the requirement to maintain the course. Both of these techniques require a data transformation in the spatial domain analogous to the power spectral density function in the temporal domain. An example using data measured before and after grading of an actual test course is presented.
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