Road surface quality measurement using inexpensive radar

The near surface dielectric characteristics of pavement can indicate the overall health of roadways and bridge decks. By performing simple and fast reflectometry measurements of the near surface, it may be possible to efficiently monitor large amount of critical civil infrastructure, and provide early alerts of the initial stages of damage. We demonstrate the variation with moisture content of surface reflected waves using a commercial-off-the-shelf 24 GHz FMCW radar. Initial experiments show that detectable amounts of water is absorbed in asphalt and concrete. The amount of absorbed water increases with micro- and macro-cracking, and this measurement will correlate with quantifiable changes in the observed return signal.