WiNRADiO Advanced Digital Suite - NAVTEX Decoder

NAVTEX (NAVigational telEX) is a system for broadcast and automatic reception of navigational, meteorogical and maritime safety information. The NAVTEX service is available worldwide on a dedicated frequency 518 kHz. The Advanced NAVTEX Decoder makes it possible to decode NAVTEX messages fully automatically, display the received broadcasts and save them to file.

Advanced NAVTEX Decoder

NAVTEX automatic tone estimation

The NAVTEX characters are transmitted at 100bits/second using a 7-bit alphabet, coded according to the CCIR476-5 standard (this is also known as SITOR-B protocol). There are two tones corresponding to "mark" and "space" of a coded character.

The mark/space tones of the received signal can be either entered manually, or can be estimated automatically. A real-time spectrum analyzer provides a handy means of determining the tone frequencies and thus optimize reception of even a very noisy signal.

The Advanced NAVTEX Decoder is supplemented with a scheduler which makes it possible to specify times and dates when the recorder should receive NAVTEX signals. This receiver can remain unattended. The Decoder will tune the WiNRADiO receiver to the specified frequency and record the received signal, both in its original form (as a wave file), as well as the decoded text.

NAVTEX scheduler

The Advanced NAVTEX Decoder can operate on real-time signals as well as on recorded wave files. Its output can be either directed to a text file, or read directly off the screen.