Armor Plate Surface Roughness Measurements

摘要

The accuracy and limitations of DoD high frequency radar signature prediction codes depend on the approximations included in the underlying algorithms. At Ka-Band and above, accurate representation of the target surfaces becomes a limiting factor in the electromagnetic simulation, since the resolution requirements are on the same order as fabrication tolerances. Even if accurate representation of test vehicles can be obtained, there may still be discrepancies in the modeled surface condition (i.e., surface texture and coatings) that could become important at high frequency. We measure waviness and roughness of various plates to know the parameter range for smooth aluminum and rolled homogenous armor (RHA). We also modify the plates by grit blasting to determine how parameters might change during surface preparation for painting. Using these roughness parameters and typical electrical characteristics for paint, we can estimate the effect of surface condition on RCS predictions at Ka-Band. For the painting process and surface roughness typical of ground vehicles, theory predicts only a small difference compared to smooth metal targets.