A radio system for determining the range and bearing of mobile equipment, such as an aircraft, relative to reference equipment such as an aircraft carrier, with low probability of interception (LPI). The aircraft remains equipped with high power range and bearing determination equipment, such as TACAN equipment. Reference equipment transmits a LPI beacon, such as a pseudo noise code spread spectrum signal through a rotating beam antenna to amplitude modulate the beacon as a function of antenna orientation. The PN code is inverted as the antenna passes through a reference bearing. Mobile LPI equipment determines bearing and generates a high power signal, such as an emulated TACAN beacon signal. High power range and bearing equipment extracts bearing information from the emulated signal and display it. Range can be determined in a cooperative mode. Mobile LPI equipment transmits a LPI interrogation signal. Reference LPI equipment returns a LPI reply signal. Mobile LPI equipment determines range from the delay time, and generates a high power reply signal from which the high power range and bearing position determination means can extract and display range information.