A two-year development and testing project is drawing to a close with the imminent delivery of the first MineVue long-range radar system to the Government of India. MineVue is the longest-range shielded radar system commercially available. It is also the first low-frequency Intrinsically Safe (ATEX) radar system in the world, suitable for use in underground coal mines.
Working with an international team of radar electronics specialists, Groundradar has initiated a project to develop the next-generation radar architecture for long-range imaging applications. The project involves the use of novel shielded antenna concepts with a continuous wave (CW) radar to achieve maximum penetration. The targeted applications would be deep mining exploration projects where radar image textural variations are of interest (e.g. BIFs) and seismic static corrections.
With the recent addition of Suriname, Groundradar has now conducted GPR surveys in every South American nation, from Colombia to Chile. Suriname also brings the total countries Groundradar has worked in to over 65.
Groundradar celebrated its busiest year in 2010, with GPR projects completed in 23 countries on all six continents. Environments ranged from the jungles of the Congo to the Outback of Australia, in temperatures ranging from +40 C (Algeria) to -35 C (Far East Russia). As industry acceptance of long-range radar grows, Groundradar’s schedule appears even busier in 2011, with all survey teams already booked through late April.
Groundradar will be exhibiting at the PDAC in Toronto, Canada (March 6-9), the world’s largest annual mining convention Visit booth 702 to learn more about Groundradar’s unique long-range GPR technology for mineral resource evaluations.
Groundradar has recently visited Estonia to take delivery of a custom dielectric permittivity probe, which is also capable of providing electrical conductivity and soil moisture readings. As the potential applications for Groundradar’s proprietary long-range GPR instruments grow, traditional limitations on suitable GPR survey locations are increasingly challenged. Groundradar will use the new probes at a variety of new application sites worldwide to test parameters critical to the prediction of radar performance. Clients may now employ this instrument prior to Groundradar’s mobilisation to provide critical measurements which Groundradar will use to determine the maximum predicted range and resolution of a survey, as well as the most suitable radar system for the task.
Groundradar’s latest custom long-range radar system, MineVue, has been trialled extensively both above and underground at a series of Indian coal mines in Jharkand and West Bengal states. The system was able to detect abandoned coal workings at impressive depths in environments where complete radar shielding was required.
MineVue was also tested in Papua New Guinea and Australia, where the system was used to detect voids in limestone to depths of over 40 m in cluttered surroundings where traditional low-frequency unshielded radar systems would have been unsuitable. Although limestone is generally an excellent radar environment, some limestones, particularly those with a weathered mantle of clays, can prove problematic for traditional radar equipment. MineVue is a hybrid radar system comprising of a real-time sampling impulse radar as well as a pulse-compression radar which is completely shielded, easily portable, deep penetrating, and continuously tracked by DGPS.
A challenging laterite project in Indonesia where unshielded antennas have been unsuccessful was the site of further MineVue surveying. The results of trials were very encouraging, opening new applications for custom GPR instrumentation.
Groundradar’s new MineVue hybrid GPR system was used extensively at a number of coal mines in India to detect abandoned workings at impressive depths from both above and within mine tunnels. MineVue is an ATEX-approved, intrinsically-safe long-range GPR system designed specifically for deep void detection in mines where unshielded antennas are unsuitable. In nearly every open-pit mine where abandoned workings pose a geotechnical and safety issue, unshielded radar antennas are generally unsuitable due to the above-ground reflections from the near-by mine walls. Similarly, unshielded antennas are impossible to use underground due to the reverberations of reflections from the opposing tunnel walls. MineVue addresses these issues by using a highly effective, yet lightweight, shield, along with two advanced long-range radar systems on a single circuit board. Acquisition and data display is handled by a small Windows Mobile device, eliminating the need for bulky laptops.
Groundradar has undertaken an unprecedented volume of long-range GPR projects during the first five months of 2010, in environments ranging from -35 C in the Russian Far East to + 40 C in the Algerian Sahara. Applications have included bauxite and nickel laterite resource delineation to iron ore and limestone exploration projects, as well as further ground-breaking work on seismic static corrections.
Two papers will be presented at the GPR2010 conference in Italy in June. “Applications of GPR to Mineral Resource Evaluations” (Jan Francke) provides an up-to-date overview of ground penetrating radar applications in the surface mining sector, including examples of laterite, bauxite, iron ore, and alluvial exploration using the latest radar technologies. “Constructing Hyrdocarbon Reservoir Analogues With Rapid-Acquisition Long-Rage GPR (Dominic Tatum and Jan Francke) present a case study of the use of UltraGPR to create a full 3D volume of the internal structure of a sand dune in southern Libya. A region of 350 m X 500 m was imaged in full 3D to a depth of 60 m with 1 m spaced lines. Over 160 km of radar profiles were acquired in less than 6 hours, yielding never before seen detail of the complex bedding strata to the base of the dune.