Marine Antenna
Dartcom 1.5m active-stabilised marine antenna installed on the oceanographic research vessel BAP Carrasco
Active-stabilised pedestal
Below-decks equipment rack
1.5m active-stabilised marine antenna
This antenna tracks 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 is CE certified and has been designed to meet or exceed military standard (MIL-STD) specifications.
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).
An F/D ratio of 0.35 and 26dBiC gain (S-band 28dBiC) achieve a system G/T of >4.3dBK at 1.7GHz and >6.7dB/K at 2.252GHz, both at 5° elevation, and a bit error rate of <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, 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 which is housed in a below-decks equipment rack.
This antenna allows future system upgrades to receive X-Band EOS data from Terra, Aqua, Suomi-NPP, JPSS and FY-3 satellites.
Marine antenna specifications
| Pedestal: | |
|---|---|
| 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 |
| Turn rate | 10°/second |
| Total weight | 180kg approx |
| Radome: | |
| Height | 1.98m approx |
| Diameter | 1.96m approx |
| Environment: | |
| Wind speeds | 185km/h (100kt) operational 240km/h (130kt) survival |
| Temperature | –10°C to +70°C operational (–40°C with optional heater) |
| Design specifications: | |
| EMI/RFI | MIL-STD-461 |
| Vibration | MIL-STD-167-1 |
| Shock | MIL-STD-901 |
| Power requirements: | |
| Voltage | 115/230V AC @ 50/60Hz |
| Power consumption | 1000VA typical |
Integrated feed/downconverter specifications
| Feed: | |
|---|---|
| Beamwidth | 3dB at 80° 10dB at 150° |
| Gain | +4.5dBi |
| Polarisation | Right-hand circular |
| Input filter: | |
| Insertion loss | 0.3dB maximum |
| Bandwidth | 120MHz maximum |
| Overall: | |
| Noise figure | 1.2dB typical |
| Gain | 60dB minimum |
| Converted bandwidth | 50MHz typical |
| Input range | 1682–1710MHz |
| IF output | 117–145MHz |