Nondestructive Testing of Nonmetallic Pipelines Using Microwave Reflectometry on an In-Line Inspection Robot. - Tobias D. Carrigan; Benjamin E. Forrest; Hector N. Andem; Kaiyu Gui; Lewis Johnson; James E. Hibbert; Barry Lennox; Robin Sloan (IEEE Trans. Instrum. Meas., 2019)