GMDSS Radio Survey Blog
Search and rescue radar Transponders (SARTs) are the main means in the GMDSS for locating ships in distress or their survival craft, and their carriage on board ships is mandatory. The SART is a small, battery powered, omni–directional radar receiver and transmitter. They may also be incorporated into a float–free satellite EPIRB. The batteries fitted to a SART allow operation in the standby condition for at least 96 h, plus a further 8 h whilst being interrogated.
A SART operates in the 9 GHz (3 cm or ‘X-band’) radar frequency band and, on receiving a signal from a ship or aircraft radar, transmits a series of response (homing) signals. The SART can be activated manually or automatically (in some cases) so that it will thereafter respond when interrogated. The method of using and activating SARTs varies over the type available, but instructions are marked on the sides of all SARTs.
