Novel electrode arrays for field data-acquisition of 2D/3D ERT
Dr. Bing Zhou
There are many traditional electrode arrays available for field data-acquisition for 2D/3D ERT. Each electrode array has its own advantages and disadvantages for field data-acquisition. Most geoengineers often confuse which produces the best image of the subsurface structure. This project employs our computer modelling software and field data-acquisition system to conduct numerical and field experiments to find novel arrays for field data-acquisition of 2D/3D ERT. A new electrode array, called the ‘full-range gradient survey’ will be examined and compared with other traditional and popular electrodes arrays.
Most popular ERT computer software uses the assumption of isotropic rocks, which means that the resistivity values of rocks are only functions of the spatial coordinates and independent on the electrical current directions. Unfortunately, many rocks have cracks, fractures and thin layers or oriented grains, all of which may cause anisotropic properties of the rocks. This project bases on our developed computer modelling software of anisotropic resistivity and investigates 2D/3D electrical anisotropic resistivity tomography, which can image anisotropic resistivity structures of the subsurface.
Multi-parameter geophysical tomographic inversion with structure constraints.
Dr. Bing Zhou
Geophysical inversion is a computerized data process to image the subsurface structure with observed geophysical data, such as seismic data, gravity data, geomagnetic data and electrical resistivity data. However, the inversion problem is often ill-posed (multi-solutions) due to a large number of the unknowns, the spatial limitation of field data-acquisition and error contaminations. To reduce the multi-solutions, some structure constraints should be applied, e.g. zero cross-gradient or experimental relationships between the parameters are incorporated into the multi-parameters tomographic inversion, so that the inverted density, elastic moduli and conductivity or resistivity sensor shows consistent images of the geological structures. This project investigates a new strategy of multi-parameter tomographic inversion with the structure constraints for all types of geophysical data.