Using the Coherent Noise in Direct Current Resistivity Surveys to Constrain 1D Inversion Models

Inversion of geophysical data is most often the last step in the interpretation of a geophysical model. However, the inverted model has limitations that are important to acknowledge. Due to the nature of geophysical data, the encountered problems are usually the following: hidden or suppressed layers, nonuniqueness, equivalence and lack of resolution in parts of the model. In addition to this, when the resistivity surveys are realized in towns or industrial areas, the acquired data are also affected by the coherent noise; these terms stand for the influence of the infrastructural anthropic settings located in the first 3-5 m depth. Using the resistivity layer equivalence principle, the influence of this superficial layer can be simulated by assuming fictive resistivity layers so that their equivalent geophysical response is similar to the measured data. Thus, the geophysical model is constrained, the flexibility of building different models to fit the measured VES curve being reduced.