Freshwater Ground-penetrating Radar

The dielectric permittivity, conductivity and velocity of fresh water causes GPR to work well on and in this media. Various publications, conference abstracts and personal comments quote different antenna frequencies as optimal for freshwater surveying: these are tested with some simple field experiments. Few publications comment on antenna orientation and these too are considered in this presentation. Following this, the effect of water temperature, conductivity, chemistry and suspended solid content is considered, with temperature showing a major imfluence on penetration and resolution. Freshwater GPR is ideal for the surveying of small, shallow (up to 15m depth) water bodies. Siltation, engineering and forensic searches can all benefit from our experiments in optimising the use of GPR on freshwater, which we show with case studies.