Improved accuracy of plane-wave electromagnetic modelling by application of the total and scattered field decomposition and perfectly matched layers

Summary In 2D magnetotelluric modelling, the standard application of Dirichlet boundary conditions (BC) may severely diminish solution accuracy, because unknown scattered part electromagnetic field is erroneously reflected at domain boundary. Therefore, we adapt total and decomposition (TSFD) to geophysical enabling fully absorbing methods, here perfectly matched layers (PML) field. Our novel TSFD divides modelling into two regions. total-field region containing area interest, computed for scattered-field boundaries, obtained field, which absorbed by PML boundaries. The plane-wave source excited interface between both Thus, reflections are eradicated leading superior boundaries can be placed closer receivers, shrinking computational problem. Especially challenging models with strong lateral changes, accuracy that approach. Owing linearity Maxwell’s equations, inaccuracy introduced electric magnetic fields using BC expected partly cancel out in transfer functions, e.g. impedance tensor. this work, quantify cancellation effect. less than typical measurement errors vast majority apparent resistivity phase data, even, when primary strongly inaccurate.