Patent ID: 7277806

Claim:
A method for removing the air wave effect from frequency domain controlled source electromagnetic survey data collected from a sea-covered region, comprising the steps of: (a) constructing a first model of the region having from top to bottom an air layer, a sea-water layer, and a sea bottom layer, said model reflecting known bathymetry and conductivities; (b) computing the electromagnetic fields due to the source at all source and receiver locations in the survey, assuming the first model; (c) constructing a second model of the region by replacing the air layer in the first model with sea-water, and then computing the electromagnetic fields for the second model at the same source and receiver locations; (d) normalizing receiver and source parameters between the computed fields and the survey data; (e) computing the air wave effect by subtracting the field produced by the second model from the field produced by the first model at each receiver location for each source location; and (f) subtracting the computed air wave effect from the actual survey data at each receiver location for each source location.