Mapping of Agricultural Subsurface Drainage Systems Using a Frequency-Domain Ground Penetrating Radar and Evaluating Its Performance Using a Single-Frequency Multi-Receiver Electromagnetic Induction Instrument. - Triven Koganti; Ellen Van De Vijver; Barry J. Allred; Mogens Humlekrog Greve; Jørgen Ringgaard; Bo V. Iversen (Sensors, 2020)