ITU-R M.629-1 PDF

This Recommendation, recognizing the importance of shipborne and aeronautical navigational radar and radar beacons (racons) for the safety of marine and air navigation, in the frequency bands 2 900-3 100 MHz, 5 470-5 650 MHz, 9 200-9 300 MHz, 9 300-9 500 MHz and 9 500-9 800 MHz, recommends that the bands of operation be optimized for the detection of racons.

This Recommendation also seeks to ensure equipment compatibility between radars, shipborns and aeronautical racons, and discourages the use of radar transponders that could be confused with racons thereby causing a hazard to navigation. Shipborne radar transponders are restricted to certain bands, and the use of certain bands used by airborne navigational radars should be minimized. Since certain radar transponders are used for search and rescue purposes, their characteristics should be such that they cannot be confused with racons.