Abstract: A novel magnetic crossed loop antenna system is provided for use with radio navigation signals, such as provided by two or more Loran-C transmitters, and in which each loop antenna is rapidly switched between the receiving channel and that of the other loop-antenna to enable the selection of one channel with the strongest signals from both transmitters, and through tuning the antenna to the Loran-C frequency and providing rate compensation and feedback to the antenna, optimum signal-to-noise ratio, sufficiently wide bandwidth to ensure time delay stability and attenuated amplifier noise are achieved, enabling greatly improved location and tracking.

Abstract: This disclosure deals with processing radio-frequency navigation signals, particularly Loran-C signals, from crossed loop antennas (H-field antennas) by shifting the signal phase from two loops to be in quadrature with respect to each other and adding them together to achieve omnidirectivity of the antenna pattern during the acquisition mode; using the stronger signal of the two during the cycle selection mode to determine the polarity of the received signals; and calculating the relative bearing angles on transmitting stations to determine, with measured bearing, the orientation of the loop antenna with respect to these stations.