HRPT/AHRPT System Marine Antenna
1.5m active-stabilised marine antenna
This antenna is designed to track polar-orbiting satellites on moving vessels using a state-of-the-art active-stabilised X-Y pedestal to compensate for pitch, roll and yaw. It has continuous axis movement to eliminate cable wrap problems without slip-rings or rotary joints. Together with the pedestal’s high speed and accuracy this ensures no “cone of silence” (data loss at high elevations).
The antenna has a 0.35 F/D ratio and 26dBiC gain (S-band 28dBiC) to achieve a system G/T of better than 4.3dBK at 1.7GHz and 6.7dB/K at 2.252GHz, both at 5° elevation, and a bit error rate of better than 1:106 from 2° elevation.
The reflector is a 1.5m diameter prime focus aluminium parabolic dish finished in light grey paint. An integrated feed/downconverter (IFD) is mounted at the focal point in a hermetically sealed unit.
The dish and pedestal assembly is mounted inside a weather-tight glass fibre radome and base with access hatch.
The dish, pedestal assembly and antenna control unit (ACU) are mounted inside a weather-tight composite radome with a hatch in the base or side. The ACU provides fully automatic control of the pedestal with an advanced stabilisation algorithm. Full diagnostics and maintenance facilities are available via the ingest PC.
The equipment rack is located below decks and contains the receiver rack, ingest PC, UPS and network switch.
This antenna is CE certified and has been designed to meet or exceed military standard (MIL-STD) specifications.
Marine antenna specifications
|Stabilisation||Active, with gyro sensors for pitch, roll and yaw rates|
|Azimuth range||No limit (continuous)|
|Elevation range||–10° to 190°|
|Pitch rate||±15° in 8 seconds|
|Roll rate||±30° in 8 seconds|
|Yaw rate||±80° in 50 seconds|
|Total weight||180kg approx|
|Wind speeds||185km/h (100kt) operational
240km/h (130kt) survival
|Temperature||–10°C to +70°C operational
(–40°C with optional heater)
|Voltage||115/230V AC @ 50/60Hz|
|Power consumption||1000VA typical|
Integrated feed/downconverter specifications
|Beamwidth||3dB at 80°
10dB at 150°
|Insertion loss||0.3dB maximum|
|Noise figure||1.2dB typical|
|Converted bandwidth||50MHz typical|