RHOTHETA Elektronik
RT-800
Wide-Band VTS Radio Direction Finder
The RT-800 is a radio direction finder for stationary coast surveillance and identification of ships that are transmitting on the VHF radio band. The bearing information from transmitters can be correlated with the corresponding radar target and AIS-position information at a VTS centre. Two or more RT-800 Systems on different locations can be used to locate a ship’s exact position by triangulation. The RT-800 can easily be integrated in a VTS environment.
| Method of bearing: | Doppler principle |
|---|---|
| Bearing accuracy1 | 2° RMS |
| Internal resolution: | 1° |
| Frequencies range | VHF Air Band 118.000 to 124.000 MHz 118.000 to 136.992 MHz (Option) Marine Band 154.000 to 163.000 MHz 137.000 to 224.995 MHz (Option) UHF Air Band 240.000 to 246.000 MHz 225.000 to 399.975 MHz (Option) COSPAS/SARSAT 400.000 to 406.092 MHz UHF FM-Band 406.100 to 410.000 MHz 406.000 to 470.000 MHz (Option) |
| Frequency stability: | ±2.0 ppm |
| Receiving frequencies tuning steps: | VHF Air Band 8.33 kHz Marine Band 5 kHz UHF Air Band 25 kHz COSPAS/SARSAT 8.33 kHz UHF FM-Band 5 kHz |
| Bearing sensitivity: | VHF Air Band ±5° bearing fluctuation: ≤ 4 μV/m / 2.5 μV/m (typical) Marine Band ±5° bearing fluctuation: ≤ 3 μV/m / 2 μV/m (typical) UHF Air Band ±5° bearing fluctuation: ≤ 6 μV/m / 4 μV/m (typical) COSPAS/SARSAT ±5° bearing fluctuation: ≤ 6 μV/m / 4 μV/m (typical) UHF FM-Band ±5° bearing fluctuation: ≤ 6 μV/m / 4 μV/m (typical) |
| Marine channels: | Channel 0 … 28 / 60 … 88 (ship / coast stations) |
| COSPAS/SARSAT freq.: | 19 Channel A to S (406.022 to 406.076 MHz) |
| COSPAS/SARSAT fast scan | Full automatic detection of any active COSPAS/SARSAT channel A to S within 400 ms |
| COSPAS/SARSAT decoding: | Reception and decoding of COSPAS/SARSAT data signal (112 or 144 bit, 400 baud, biphase L encoded, phase modulation, with Bose-Chaudhuri-Hocquenghem errorcorrecting code, specified according to COSPAS/SARSAT) |
| Monitoring/Scanning modes: | Monitoring: 121.5 MHz and three selectable frequencies are monitored during normal operation. Standby: COSPAS/SARSAT and 121.5 MHz emergency frequencies are monitored. Fast Marine Ship Band Scan: Fast scan (without gap) of all ship channels [01 ... 88] within approx. 3 sec. Fast Channel Scan: Fast scan of up to eight freely selectable frequencies / channels within approx. 2 sec. |
| Signal filtering: | Frequencies can be filtered for distress signal modulation (false alarms disabled) A3E |
| Bearable modulation: | F3E, A3X (Distress signal modulation), F1 D, G2D, COSPAS/SARSAT Bearing largely independent of modulation |
| Polarization: | Vertical |
| Polarization error: | ≤ 5° at 60° field vector rotation |
| Cone of silence: | 30° to the vertical |
| Response time2: | ≤ 50 ms (with sufficient reception field strength) |
| TFT graphic display: | 800 x 480 pixel (max. brightness 950 cd/m², continuously / automatic control) |
| Power supply: | 115 to 230 VAC ± 10 % / 50 to 60 Hz |
| Power consumption: | Nominal 30 W @ 230 VAC |
| Audio out: | Internal speaker 4 W Line out (adjustable from 100 mVPP to 2000 mVPP) |
| Interface: | Ethernet Interface for complete remote control (NMEA Protocol: Input / Output) Ethernet Interface for IP streaming audio out RS232 (NMEA Protocol: Input / Output) PTT input (for ground transmitter suppression) Alarm Relay Output Input for optional external GPS (RS422) |
| Options: | Software “DF Commander” | Lightning Protection Rod | UTC time base |
RT-800
Accessories
Lightning protection rod
The Lightning Protection Rod for precision direction finders is designed to protect RHOTHETA direction finders against the effects of direct lightning strokes into a direction finder system.
Optional Frequency extensions
F1 VHF-Airband: 118,000 – 136,992 MHz; F2 VHF-Marineband: 137,000 – 224,995 MHz; F3 UHF-Airband: 225,000 – 399,975 MHz; F4 UHF-FM Band: 406,100 – 470,000 MHz
The Optional Frequency extensions can be ordered seperatly to extend the frequency range of each system individually.
DF Commander MK2 Software
The DF Commander MK2 software enables remote control and monitoring of radio direction finding systems. Besides displaying the direction finding results on different electronic charts, the software is able to calculate cross bearings on different frequencies. Soundings, cross bearing results and status information of radio direction finding systems are made available via an integrated server. Radio direction finding systems can also be set and controlled via the same server. Thus the software is to be understood as a DF service.
DF-Emmulator Software
The "DF Emulator" is a software that emulates a bearing system on a Windows PC by playing a pre-recorded log file. In the simplest case, the DF emulator uses the serial COM port of the PC to transfer the data via RS232 to another PC or system that displays the bearing data. This software is designed for projects like bearing data integration in radar displays or other map- and control displays and is intended to facilitate the work of integrators.
GPS UTC Timebase
By connecting the RT-800 with a GPS-mouse, it is possible to provide a peak data packet transmitted via LAN with a UTC time stamp. This ensures that it is possible to display the pitch data of different direction finding systems in a synchronized manner and triangulation for position determination on a map software becomes possible.
RT-800
