Astronautics recently completed successful delivery and trials for a Computerized Maritime Navigation system, C-MAN, for two submarines. C-MAN was developed to deliver more accurate platform positioning for combat systems without having to rely on a GPS. The C-MAN system is composed of the inertial navigation system (INS), the main navigation computer (MNC) and the control display unit (CDU). The system allows submarine navigation personnel to acquire, process and distribute the full range of inertial and navigational information. C-MAN is a modular and cost-effective system based on open architecture, ranging from a basic single sensor for small vessels to a high-end fully redundant system.
Underwater navigation, especially for submarine, requires accurate, independent navigation without any assistance from external sources. Astronautics meets this challenge with its new C-MAN system. The featured technology of the C-MAN system is a monolithic ring laser gyro INS sensor – “SEANAV”, with embedded GPS/DGPS receiver. The system is operated and controlled by the Human Machine Interface of the Main Navigation Computer (MNC), using the functions of the computerized control and display unit (CDU), which is integrated with the navigation system and other on-board sensors and sub-systems.
The MNC is the core of the navigation system, collecting data from all navigation sensors and calculating the information utilizing Astronautics’ unique algorithms. The MNC distributes the optimal navigation data to the vessel’s users. It is based on an Open Architecture (OA) concept that enables flexibility and scalability, and specified with modular design based on standards and COTS.
The ring laser gyro (RLG) SEANAV offers superb accuracy together with essential durability. The unique monolithic design of the RLG sensor also results in improved reliability at a reduced life cycle cost compared to conventional gyros. The C-MAN position accuracy is less than 1.0nm TRMS 10 Hrs. Heading accuracy (GPS aided) is less than 1.2 arc min RMS. Roll/pitch accuracy is less than 0.9 arc min RMS, while typical alignment time is 15 minutes.
Nir Itzhaky, Director of Business Development for Astronautics C.A. says, “The C-MAN fulfills the need for high-end navigation system with high accuracy. The C MAN has now proven itself as a compact, lightweight, low-cost integrated system suitable for multiple types of maritime navigation applications. The C-MAN is especially suited for new or retrofitted platforms due to its high accuracy, easy installation and maintenance with modern and state of the art interfaces for a variety of sensors and users.”
Astronautics’ C-MAN has proved its excellent position accuracy while performing the 2 submarines Sea Acceptance Test while using the FREE INERTIAL Mode of operation and without navigation sensor aiding. The FREE INERTIAL mode was conducted by denying all aiding inputs (i.e. GPS, speed log etc.) The 24 hr under-water sails were executed most of the time at high seas (Sea state 3 - 5) with tough maneuvers which included changes of speed, depth and diversion angles, circles in a different diameter and at different speeds. The resulting accuracy has been similar and repeatable, demonstrating performance better than half mile position accuracy after 24 hrs, without the use of any navigation aid.
