Charter Oaks Ltd is an established utility mapping company based in South Yorkshire. We specialise in utility mapping surveys sung a variety of techniques including but not limited to radio frequency and ground penetrating radar. We also GPR to locate other sub-surface anomalies such as voids, cellars and mine shafts. Our survey teams consist of two people, the surveyor and an assistant, both experienced in the use of all of the equipment operated. Y Charter Oaks. The senior surveyor will have a minimum of 5 years experience in the field.