Radar marker
Radar marker ( Ramark ) is the name of a radar buoy that continuously and without external triggering emits a radar signal in the form of a Morse code .
It is part of the equipment of particularly distinctive sea marks such as B. lighthouses, lightships, large barrels, light barrels or landmarks. It is broadcast in the frequency band from 9.32 GHz to 9.5 GHz. When a ship's rotating radar antenna is aimed at the Ramark beacon, a center-to-edge guideline appears on the radar screen.
Identifier
The identifier of the beacon is displayed as a Morse code consisting of “lines” and “dots”, slightly wedge-shaped, roughly corresponding to the shape of the main radiation beam, in a radial direction. The identifier begins at the leading edge of its initial character after the correct position. It is also possible that only the identification of the beacon carrier is visible on the screen if it is "close" behind the radar chimney.
technology
The beacons are broadband radar wave transmitters in the 3 cm and / or 10 cm wave band ( X band ) with an all-round antenna. They can be activated by radar systems on ships from a distance of 18 km to 28 km. The beacons are equipped with receivers and activate themselves when they receive radar impulses from the on-board radar devices and then each send their identification.
In addition, there are radar (marker) beacons that transmit continuously or at a certain rate. Only these beacons are radar markers in the narrower sense.
Many marker beacons send the identifier "-", which corresponds to the letter "T" in Morse code. On the radar image with a radial extension (line) of about 5 km.
Individual evidence
- ↑ Dieter Lunge: Ship Radar. Basics.