A method of obtaining an electromagnetic propagation measurement of a subterranean geologic formation, said geologic formation being intersected by a borehole, the method comprising: - providing a device within the borehole, said device comprising: a transmitter (Tx), located on said device, for transmitting a signal; a first receiver and a second receiver located on said device, for receiving the transmitted signal; and, a processor means for processing the received signals; - generating the signal from the transmitter (Tx); - receiving the transmitted signal at the first and second receiver (Rx1, Rx2); - injecting a calibration signal with a calibration circuit (62, 64) into the first receiver and the second receiver; - processing the receiver signal and the calibration signal within the processor means and wherein the step of processing the receiver signal and the calibration signal includes calculating a phase difference free of data acquiring errors by computing the phase difference as follows: PD = θ M 1 − θ M 2 − θ MC 1 − θ MC 2 - Wherein PD is the phase difference free from acquisition errors; - θ M1 is the measured phase of the uncalibrated receiver signal from the first receiver; - θ M2 is the measured phase of the uncalibrated receiver signal from the second receiver; - θ MC1 is the measured phase of the calibration signal from the first receiver; and, - θ MC2 is the measured phase of the calibration signal from the second receiver; - correcting data acquisition errors related to the first receiver and the second receiver; - determining the electromagnetic propagation measurement, characterized in that the calibration signal is injected into the receiver front ends using a current loop (78, 80), wherein the current loop (78, 80) has a current transformer (82, 84) placed therein and the method further includes sampling the current in the loop (78, 80) with a current sampling resistor (88, 90) on the current transformer (82, 84). - providing a device within the borehole, said device comprising: a transmitter (Tx), located on said device, for transmitting a signal; a first receiver and a second receiver located on said device, for receiving the transmitted signal; and, a processor means for processing the received signals; - generating the signal from the transmitter (Tx); - receiving the transmitted signal at the first and second receiver (Rx1, Rx2); - injecting a calibration signal with a calibration circuit (62, 64) into the first receiver and the second receiver; - processing the receiver signal and the calibration signal within the processor means and wherein the step of processing the receiver signal and the calibration signal includes calculating a phase difference free of data acquiring errors by computing the phase difference as follows: PD = θ M 1 − θ M 2 − θ MC 1 − θ MC 2 - Wherein PD is the phase difference free from acquisition errors; - θ M1 is the measured phase of the uncalibrated receiver signal from the first receiver; - θ M2 is the measured phase of the uncalibrated receiver signal from the second receiver; - θ MC1 is the measured phase of the calibration signal from the first receiver; and, - θ MC2 is the measured phase of the calibration signal from the second receiver; - Wherein PD is the phase difference free from acquisition errors; - θ M1 is the measured phase of the uncalibrated receiver signal from the first receiver; - θ M2 is the measured phase of the uncalibrated receiver signal from the second receiver; - θ MC1 is the measured phase of the calibration signal from the first receiver; and, - θ MC2 is the measured phase of the calibration signal from the second receiver; - correcting data acquisition errors related to the first receiver and the second receiver; - determining the electromagnetic propagation measurement,