Patent ID: 7801681

Claim:
A computer implemented method for estimating error in measured data from a controlled-source electromagnetic survey of a subsurface region, comprising: (a) selecting data from the electric or magnetic field survey data, said selected data corresponding to a plurality of different offsets, wherein the term offset means source-receiver spacing, and to a selected single frequency in the source's signal's frequency spectrum; (b) generating a geo-electric model of the subsurface region, said model including at least resistivity or conductivity as a function of position in the region; (c) using a programmed computer to solve electromagnetic field equations to simulate the survey's electromagnetic responses for said selected frequency and for source and receiver locations corresponding to said selected data, using the geo-electric model of the subsurface region and survey source parameters; (d) selecting a near-zero offset range; and (e) estimating data error at all offsets by comparing measured survey data to simulated data at one or more offsets within said selected range of near-zero offsets, said estimated error providing a means for correcting measured data.