2-dimensional Inversion of Resistivity and IP data with Topography

Two-dimensional, smooth-model inversion of resistivity and induced polarization data produces image-like, electrical property sections which improve the data's interpretability. Recent software improvements enable routine smooth-model inversion of resistivity and induced polarization (IP) data. Nearly uniform starting models are generated by running broad moving-average filters over lines of dipole-dipole or pole-dipole data. Model resistivity and IP properties are then adjusted iteratively until calculated data values match observed values as closely as possible, given constraints which keep the model section smooth. Calculated values are generated with a finite element algorithm which can be adapted for accurate two-dimensional modeling of data collected in rough terrain. Smooth-model inversion of sample data show the method's utility as an interpretation aid and the importance of modeling topography in areas with significant relief.