I-MAST 400 I-MAST 400, the larger member of the Thales family of Integrated Masts, is an integrated naval sensor & communications suite packed into an advanced mast structure. It combines multiple state-of-the-art sensor and communications subsystems, auxiliaries required for safety, maintenance, navigation, etc. and infrastructure into a single pre-outfitted and pre-tested package that is installed on top of a ship's superstructure at the final stage of the shipbuilding process. I-MAST 400 combines the majority of the sensor and communications functionalities of the ship into one integrated mast structure. This includes a volume search radar, an electro-optical/infrared panoramic surveillance sensor suite, an integrated radio communications suite, a non-rotating identification friend-or-foe (IFF) antenna ring and extensive satellite communications capacity. In addition, I-MAST 400 provides radar ESM. Pre-planned options include a surface search and helicopter guidance radar, Link 16 capability and communications ESM. All I-MAST 400 functions are optimised to provide high performance in challenging littoral environments. The mechanical structure creates a protected and conditioned environment that enables easy access and maintenance. I-MAST 400 is primarily intended for large ocean going patrol ships that are used for extended out-of-area missions in low intensity conflict areas. In general the I-MAST 400 will provide surveillance & communications capabilities and support defence against asymmetric attacks, both in open ocean as in littoral environment. It can be optimised to specific missions by the choice of specific subsystems and by the size of the main radar array.