1. A method for determining a parameter of interest of a region of interest of the earth, the method comprising: (a) measuring at least one component of potential fields data at a plurality of locations over a region of interest including a subterranean formation of interest, said potential fields data selected from magnetic data and gravity data; (b) determining an initial geophysical model of the region including the subterranean formation of interest; (c) for said model, estimating a value of said at least one component of geophysical tensor data at said plurality of locations using an interior-point method for constrained optimization; (d) determining a difference between said estimated value and said measured value of said measurements at said plurality of locations; (e) updating the geophysical model of the region based on said difference; (f) iteratively repeating steps c-e until said difference is less than a predetermined value; and (g) using said updated model to determine the parameter of interest.