Quantification of the Resolution in the Inversion results from Towed Streamer EM Data

The resolution of resistivity models from 3D inversion of Towed Streamer EM data is analyzed using the resolution matrix. In particular, a new resolution length derived from the resolution matrix is introduced. This measure is obtained by dividing the volume of an inversion cell with the corresponding diagonal element in the resolution matrix. Hence, the measure is independent on the actual cell discretization of the inversion domain. Resolution lengths are calculated both for a hypothetical case with noise free data and for resistivity sections obtained with regularized 3D inversion. The resolution of the ideal case with no noise constitutes the upper limit of the best possible resolving power of the Towed Streamer EM data. This limit is then compared against the results where smoothing regularization has been applied in the 3D inversion. A comparison is illustrated for inversion results of Towed Steamer EM data from a survey line in the Barents Sea.