Radar Transponder (RACON)

Racons are receiver/transmitter devices operating in the maritime radar frequency bands (9 and 3 GHz) that enhance the detection and identification of certain radar targets. A Racon responds to the presence of a ship’s radar by sending a characteristic pulse train. The response appears as a coded mark (or “paint”) on the ship’s radar display that highlights the range and bearing of the racon. The displayed paint has a length on the display corresponding to a few nautical miles and uses a Morse character for identification. When a racon receives a radar pulse, it responds with a signal on the same frequency which leaves an image on the radar display. This takes the form of a short line of dots and dashes forming a Morse character radiating away from the location of the beacon on the normal plan position indicator radar display.

A racon is generally considered to be a supplementary aid to navigation installed at sites that would also be marked with a light. As noted in the IMO carriage requirements contained in Chapter V of the SOLAS Convention,1974, a large number of vessels are capable of making use of a racon. Racons used for purposes other than aids to navigation is prohibited, and they are used to mark:

  • lighthouses and navigation buoys
  • offshore wind farms
  • positions on inconspicuous coastlines
  • offshore oil platforms and other structures
  • environmentally-sensitive areas such as coral reefs
  • ranging and identification of locations on inconspicuous coastlines
  • marking hazards
  • indicating navigable spans under bridges
  • as a leading line

Their characteristics are defined in the publication: ITU-R Recommendation M.824, Technical Parameters of Radar Beacons (RACONS). 

General data

General RACON information

Racon Types
There are two different operating modes:
- The frequency-agile racon which represents current technology, and;
- The original and largely obsolete swept-frequency racon.

Frequency-Agile Racon: Responds on the frequency on which they are interrogated and hence the response could be re-painted on each radar sweep.
However, to avoid masking other features on the radar screen the racon response is usually switched on and off on a preset cycle.

Table 3.9 Preferred terminology for the description of racon operating frequencies.

Preferred Terminology Alternatives
9 GHz 9300 -9500 MHz X - band 3 cm
3 GHz 2900 -3100 MHz S - band 10 cm

Signal Characteristics

Racons usually operate on the 9320 MHz to 9500 MHz marine radar band (X-band), and most also operate on the 2920 MHz to 3100 MHz marine radar band (S-band). Modern racons are frequency-agile; they have a wide-band receiver that detects the incoming radar pulse, tunes the transmitter and responds with a 25 microsecond long signal within 700 nanoseconds.
DOWNLOAD: IALA Guidelines on Racon Range Performance (Maritime Radar Beacons (RACONS) R-101)

Contact us

Kristian Kristensen

Phone: +45 43 68 50 04

Email: ksk@hansbuch.dk

Get a call or get an email with further details on our products.

[ninja_forms id=28]
Get data sheet

Get an overview of the technical data, applications and design.

Sign up for newsletter

Get advice and insights on topics that interest you, directly in your inbox