Radar systems for the exploration of earth-masses around bore-holes
The need to have a comprehensive and detailed knowledge of the structure and characteristics of rock masses around boreholes can only be served by radar technologies. Such technologies are also used for the exploration of salt deposits around gas storage caverns. The directional borehole radar is the only technique in this field that is able to provide true 3-dimensional information. Currently the only equipment available worldwide for general applications is a borehole radar system manufactured by Malaa Geoscience (Sweden), one of the partners of the current project. The equipment, due to inherent design limitations, can only operate to a maximum depth of 1500 meters. The software necessary for the interpretation of the radar's data has low speeds of data acquisition and finally the directional interpretation is at times uncertain. Acknowledging the limitations and the high operating costs of the current radar system has, warranted the need for better and improved equipment. The BORATYEC project has designed and developed a completely new radar system. The new system consists of a directional module for deep operation that expands the operating depth from the previous 1500 meters to 2500 meters and will be further expanded in future stages of the project. The module is connected with a standard logging cable. The system has also a module for fast data acquisition, which will be of great assistance with shallow tomographic data. The previous uncertainties in the directional interpretation no longer exist since project partners have solved the theoretical problem of directional antenna orientation. The solid theoretical understanding facilitates better survey planning and interpretation. For deeper boreholes, a special radar system was designed opening up new markets since no system until now could operate at great depths and under such hitherto impossible conditions that exist at those depths. For shallow investigations another system specific to shallow conditions of operation has been developed. Its operating costs are substantially lower while due to software improvements the quality of the result is considerably improved. The industrial objective of the project partners was twofold: first the design of a new instrument and second the expansion of its application range. To achieve this objective the new directional radar system has undergone a comprehensive test measurement programme applied to mining, quarrying, engineering and environmental and hydro- geological problems. The radar system is now available for demonstration and market introduction.
