Our preference goes to the LCDC Ku-135 antenna when exploitation conditions are among the harshest. It distinguishes from the best stabilized stations available on the market (Cobham, Intellian…) by its design philosophy. Unlike the majority of its competitors, its stabilisation system is designed like a robot.
Each movement of its reflector is anticipated by a calculation, it is pointed on the satellite following a periodical computation every 100ms. The position is then confirmed by the signal level.
The computing takes its assumptions:
- In a database, hosted in the outdoor part under the radome, which contains the list of all available satellites and their characteristics.
- On a 3D antenna reflector pattern modelling. Thus, with two successive measurements of the intersection of the reflector axis with the surface of the antenna pattern envelop – the axis of which is the line-up to the satellite – the system controls the servo-motors in order to make them match. Data such as the vessel heading, the GPS coordinates, the various acceleration sensors, known obstructions (antenna tower, radars, working platforms, etc.) are used only at system start up.
This design thus allows the various servo-motors to achieve a soft motion of the reflector, without strokes or abrupt movements. A deceleration is integrated so as to reach the computed position at close to zero speed, from which it starts off again with an accelerated motion. The result is thus an eased and optimized maintenance thanks to a high MTBF.
The system is based on four axis operated by servo-motors driven by a unique and patented tracking algorithm allowing the use of light motors (200gr) with low power (100W) thus without induced currents in rotating switches.
The station is compact and robust, radio equipment (SSPA, BUC, LNB) is positioned at the centre of the system, no mechanical balancing needs to be performed.
These specificities make this antenna onerous (15% to 20% more expensive than its competitors) where the price is to be justified by an exploitation is harsh sea states, anywhere on the globe (Zenith paradox arising when sailing close to the equator and depending on the geostationary orbital position) and in specific environments.