Technology for measuring orientation is described. Signals can be received from a signal source having a known location via at least two antennas of the interferometer that are separated by a predefined distance. A delay between receiving the signals from the signal source at the at least two antennas of the interferometer can be calculated. A line of bearing (LOB) of the interferometer with respect to the signal source can be determined based on the delay between receiving the signals at the at least two antennas from the signal source. The orientation of the interferometer can be measured in a global coordinate system using the LOB of the interferometer with respect to the signal source.