The SART is a search and rescue radar transponder. It is portable and can be operated from the parent vessel or from a survival craft. Once operated the SART is intended to indicate its position to search units of either the surface vessel or aircraft type.
Operation of the SART is on (9 GHz) and can be interrogated by units operating 3 cm radar. Specification of the SART is such that it is identifiable at 5 nm from operation at 1 metre above surface. In comparison an aircraft could detect at about 40 miles because of its increased height.
SARTs are activated by the radar energy of an approaching search unit and starts its own transmission. The radar signature produced is a radial line of 12 dots over an approximate eight mile length on the search vehicles radar, from a position just beyond the position of the distress. As the search unit closes the target to about 1 nm, the dots become small arcs. The signature will change again to concentric circles when the range closes to a few hundred meters.
General features, location and functioning of the SART
SART is made of fiber reinforced plastic which can withstand and bear the prolonged exposure to sunlight and extreme weather conditions
It is capable of floating free of the survival craft
International orange in colour
SART is mounted on a mounting bracket which is fixed to a bulkhead on ship, on the bridge
It operates on the 9GHz frequency band (9.2 to 9.5 GHz) and generates a series of clips on the radar it is interrogated by (3 cm/X Band radar).
They can either be portable or fixed permanently into the survival craft
The SART is activated manually and hence responds only when interrogated
When activated in a distress situation, the SART responds to radar interrogation by transmitting a signal which generates 12 blips on the radar and turns into concentric circles as the range between the two reduces
On the PPI, the distance between the blips will be 0.6 miles
This signal is very easy to spot than a signal echo from say, a radar reflector
The SART also has a audio or visual indication of its correct operation and informs survivors when interrogated by the radar
An audible beep is heard every 12 seconds when there are no radars in sight and every 2 seconds when interrogated by radar
For best results, search Radar Operators should:
(a)Turn off the anti-rain control
(b)Place gain control to maximum
(c)Operate on 6 nm range or less
(d)Reduce clutter by down tuning slightly
(e)Reduce range and gain control when closing target.
NB. SARTs are not designed to operate with 10 cm radar.