General

A Search and Rescue Transponder, or SART, is a battery-powered portable device, which may be used by a
survival craft to indicate its position to searching aircraft and vessels.

The SART operates in the 9.3 to 9.5 GHz band and will respond only to radar equipment operating on those frequencies (X Band, 3 Centimetre radar). The SART will not respond to 3 GHz (S-band, 10 Centimetre) radar. The SART should operate in standby mode for a minimum of 96 hours with a further eight hours of transmission.

Positioning of the SART

Under no circumstances should the SART be placed in the water. The SART should be mounted at least one metre above the water line. When in the survival craft survivors should position the SART as high as possible with the aid of an oar or the lifeboat mast.

Some manufacturers will supply the SART with a short telescopic-type mast of approximately one metre in length.

SART Operation

Once switched on the SART will scan the X Band of radar frequencies. When a searching radar is detected the SART will lock onto that particular radar frequency and commence to transmit on the entire X Band, thus enabling all vessels in the vicinity to receive an indication of the SART transmission.

On detecting signals from distant radar equipment, an activated SART will generate a series of response signals of twelve blips which will be displayed on the receiving radar screen, extending in a line, approx 5 to 8 nautical miles in length, outward from the SART position, along its line of bearing. This unique radar signal is easily recognised and the rescue vessel or aircraft can locate the survivors. (See Fig. 5 & 6)

An interrogated SART will provide proof to survivors of operations by means of an audible and/or visible flashing light.

Location distances

A SART should respond to a ship’s radar with a scanner height of 15 metres at a distance of at least 5 nautical miles. Once locked on to a searching radar there will be a slight delay in the changeover from the SART’s standby or receive mode to transmit mode. This slight delay may cause a small position error up to 150 metres on the radar screen of the blip associated with the position of the SART. Subsequent radar sweeps will confirm the actual location of the SART.