Marine Radar and ARPA
Shipborne radar and ARPA: SOLAS V/19 carriage tiers, X-band and S-band, tracking aids and the MSC.192(79) performance standard.
Marine radar is carried under SOLAS regulation V/19 in three steps: a 9 GHz (X-band) radar and an electronic plotting aid from 300 GT and on passenger ships, an automatic tracking aid from 500 GT, and a 3 GHz radar, or a second 9 GHz radar where the Administration considers it appropriate, with a second tracking aid from 3,000 GT. Ships of 10,000 GT and upwards add an automatic radar plotting aid (ARPA) able to plot at least 20 other targets, with trial maneuver.
Radar installed on or after 1 July 2008 meets the IMO performance standard MSC.192(79), adopted 6 December 2004. The full article will cover X-band and S-band trade-offs, target tracking and its use under COLREGs Rules 6, 7 and 19. See SOLAS Chapter V .