A method for forming a wellbore in an earth formation, comprising: positioning a drill string in a wellbore ; the drill string including a bottom hole assembly (BHA) that includes: a steering unit ; one or more sensors located on the BHA , including at least one formation evaluation sensor, the one or more sensors responsive to one or more formation properties including resistivity; and one or more orientation sensors located on the BHA responsive to the current orientation of the BHA in a wellbore , including at least one of: a BHA azimuth sensor; a BHA inclination sensor; and a BHA coordinate sensor; receiving information from the one or more sensors located on the BHA related to the formation properties and information from the one or more orientation sensors related to a current orientation of the BHA in the wellbore ; processing the information using a computing device to calculate a current position of formation features with respect to current wellbore position in real time; comparing the current position of formation features to a prescribed position of the formation features with respect to the wellbore; and causing the steering unit to change a course of the BHA during a drilling operation based on the comparison, characterized in that : the computing device is a programmable optical computing device that utilizes photons to perform calculations, wherein the programmable optical computing device utilizes a laser to transmit light through a liquid crystal grid, and wherein the programmable optical computing device calculates the current position of the formation features with respect to the current wellbore position in real time by performing at least a two-dimensional inversion. positioning a drill string in a wellbore ; the drill string including a bottom hole assembly (BHA) that includes: a steering unit ; one or more sensors located on the BHA , including at least one formation evaluation sensor, the one or more sensors responsive to one or more formation properties including resistivity; and one or more orientation sensors located on the BHA responsive to the current orientation of the BHA in a wellbore , including at least one of: a BHA azimuth sensor; a BHA inclination sensor; and a BHA coordinate sensor; a steering unit ; one or more sensors located on the BHA , including at least one formation evaluation sensor, the one or more sensors responsive to one or more formation properties including resistivity; and one or more orientation sensors located on the BHA responsive to the current orientation of the BHA in a wellbore , including at least one of: a BHA azimuth sensor; a BHA inclination sensor; and a BHA coordinate sensor; receiving information from the one or more sensors located on the BHA related to the formation properties and information from the one or more orientation sensors related to a current orientation of the BHA in the wellbore ; processing the information using a computing device to calculate a current position of formation features with respect to current wellbore position in real time; comparing the current position of formation features to a prescribed position of the formation features with respect to the wellbore; and causing the steering unit to change a course of the BHA during a drilling operation based on the comparison, <EOS>