The C2SAT antenna is our preferential choice in systems where the operating conditions are very harsh. It is among the best available on the market of stabilised antennas (Seatel, Orbit.) because of the philosophy of its unique construction. Unlike most of its competitors, its stabilisation system is designed to act like a robot. Each movement of the reflector is anticipated by a complex calculation: the reflector is pointed at the satellite according to a calculation repeated every 100 ms, this position is then confirmed by the received signal level and not after a permanent pursuit of the best signal level.
The calculation uses information from :
- A database housed in the radome which contains a list of all the available satellites and their characteristics,
- The modelling of the 3D radiation pattern of the reflector. Thus in two successive measurements of location of the intersection of the axis of the reflector, which is parallel to the direction of the satellite, with the surface of the envelope of the radiation pattern are compared. Using the derivative of the signal level, the system will act to always replace the two axes jointly.
- The system requires servomotors to perform the tracking. Data such as the ship’s heading, GPS data, information from the various acceleration sensors and obstructions (antenna tower, radar, working platforms etc.) are only required for starting the system.
The operation then allows different servomotors to move the reflector smoothly and without sudden movements. The alignment procedure starts with an accelerated motion, and then slows down before arriving at the calculated position. There will be no surges current, low intensity in the slipring etc.
The result is ease of maintenance and a very high MTBF figure because
The system has 4 main axis operated by servo-motors on a single tracking algorithm and thus can use small servo-motors (200g) and low power (100W), therefore strong currents induced in the rotary switches are avoided.
For comparison with antennas such as those manufactured by “Orbit” have servomotors weighing 16 lbs.
The station is compact; the robust radio equipment (SSPA, BUC, LNB) is placed at the centre of the system, no individual mechanical balancing is required.
These characteristics make it an expensive antenna (15 to 20% more expensive than its competitors) where the price must be justified by the necessity for the ships telecom system to remain operational even in very high seas anywhere in the world.