A method for electromagnetic exploration includes imparting a first electromagnetic signal into subsurface formations from a first location and imparting a second electromagnetic signal into the formations from a second location substantially contemporaneously with imparting the first electromagnetic signal. The upper surface is imprinted with a repeating paving stone pattern of a square adjacent an octagon. Database types can be chosen either by user directly or by platform automatically or semi-automatically based on data types and data operation characteristics. The corrosion-resistant charge injection accelerating layer has been formed by subjecting a surface layer in the metal layer to plasma treatment using an oxygen atom-containing gas. In some embodiments, the device includes an elongate shaft, a filter coupled to the shaft, and a proximal stop coupled to the shaft.