DSCdecoder

DSCdecoder decodes Digital Selective Calling (DSC/VTS) messages and Navtex and DGPS messages in the Maritime Mobile Service.

DSCdecoder allows you to use your PC and soundcard to decode maritime mobile service messages using the Digital Selective Calling (DSC) system and also DGPS and Navtex broadcasts. DSC signalling is used in the MF, HF and VHF bands for distress and calling between ships and coast stations. Navtex messages are broadcast by coast stations and carry information about navigational warnings and weather forecasts. Messages that can be decoded include routine calls for test purposes between ships and coast stations; calls to establish communication by some other means (voice, etc.) between a ship and a coast station; notification of routine and safety messages from coast stations; Vessel Traffic Service (VTS) messages, distress messages and distress relay messages. DSCdecoder will decode these messages and display and log their content.

DSCdecoder Features

DSCdecoder decodes the DSC digital signals from ships and coast stations using the sound card in your PC. You need a suitable MF, HF or VHF band radio receiver tuned to one of the DSC distress and calling channels or to one of the Navtex channels. The program decodes the received digital data and displays and logs the messages.

Signal mode - In Signal Mode, DSCdecoder displays the raw digital signals on your PC screen in a diagnostic display which helps you to set up the system and tune the receiver. DSCdecoder also displays a rolling audio spectrum display if that is easier for you.
Spectrum mode - In Spectrum Mode, DSCdecoder displays the spectrum of the audio signals on your PC screen as an aid to tuning the receiver. You can click on the spectrum display to retune the decoder to take account of any mistuning fo the radio itself.
Message mode - In Message Mode, DSCdecoder displays each decoded message in plain language on your PC screen. The sender, the recipient, the priority, and any frequency, position, or enquiry data are decoded and displayed.
Chart mode - In Chart Mode, DSCdecoder displays the position of any ship or call area that has been included in any decoded message. DSCd charts are compatible with ShipPlotter charts.
ATIS decode - In addition to decoding the MF, HF and VHF modes of DSC, DSCdecoder is also able to decode the ATIS (Automatic Transmitter Identification System) data bursts that are transmitted on the regular VHF marine channels in the Benelux and Rhineland river systems.
Navtex decode - In addition to decoding the MF, HF and VHF modes of DSC, DSCdecoder is also able to decode Navtex transmissions which are used for navigational warnings and weather bulletins. As the example at right shows, Navtex messages that contain positions in a recognisable format also plot in chart mode. The message identifier plots by default and if the cursor hovers over the identifier, the content of the message is displayed over the chart.

DGPS decode - DSCdecoder is also able to decode DGPS transmissions which are used for added navigational accuracy using GPS.
Message log - DSCdecoder stores all messages received and decoded in a text file for later analysis and review. The log file is time stamped and DSC messages are punctuated for easy importing into a spreadsheet or database.
Alarms - DSCdecoder can be configured to sound an audible alarm on receipt of a distress call or a distress relay message. It can also be configured to sound an alert on receipt of any message containing a specified text string such as the MMSI number of a ship or the name of a coast station. You can even configure it to send an email to a designated address on receipt of an alarm or an alert.
Floating window - DSCdecoder can be configured to display a floating window showing just the last two messages. The window is always on top, regardless of the focus that some other application may have. The means that you can work on something else while keeping an eye on messages as they come in.
Automatic lookup - DSCdecoder can access the ITU database of MMSI numbers to retrieve the name and callsign of any ship that is mentioned in received messages. Coast station MMSI numbers are translated using a text file that accompanies the program.
Automatic FTP transfer - DSCdecoder can perform an FTP transfer to a user-defined FTP server sending either the most recent messages as a text file, or the current chart image as a JPEG File at user-defined intervals.
Automatic tuning - DSCdecoder can auto tune the demodulator to accommodate a range of subcarreir frequencies to relieve the user of the need to tune the receiver precisely.
UDP output - DSCdecoder can send decoded data to a UDP/IP destination for processing elsewhere on the network.
Navtex serial input - DSCdecoder can accept serial Navtex messages from the NASA Navtex Engine. Messages with positions in them are displayed grpahically on a chart.
OLE/COM access - DSCdecoder provides an OLE/COM (ActiveX) interface so that scripts or other applications can read the position data received in decoded DSC messages.
Script - The program can execute a command script to allow fully automated monitoring and surveying including control of receiver tuning.

Requirements to run DSCdecoder

Pentium level PC running WinXP, Vista, Win7, Win8, Win8.1, Win10 with compatible sound card
An MF or HF receiver with USB, LSB or CW modes or a VHF band radio receiver with NFM mode. The receiver must be tuned to one of the DSC distress and calling channels or to one of the Navtex channels. The receiver audio output must be connected to the Line-In connector on your PC.

Download DSCdecoder

DSCdecoder can be downloaded freely and comes in a self-extracting ZIP file which automatically installs itself. The file size is a modest 1.4 Mb.

Download DSCdecoder (version 4.5.9) Now.

Registration of DSCdecoder

DSCdecoder can be freely downloaded and used for 21 days. After that time it must be registered. Registration can be done swiftly and securely on-line and costs only Euro €25 (plus VAT for EU residents) for personal use. A higher fee applies to professional or commercial use of DSCdecoder. We strongly recommend that you ensure that DSCdecoder performs to your satisfaction before registering.

Register DSCdecoder Now.

Disclaimer

There are considerable variations in the legislation concerning radio reception in the different administrations around the world. It is your responsibility to determine whether or not your local administration permits the reception of DSC messages from ships. It is specifically forbidden to use DSCdecoder for any illegal purpose whatsoever. The existence and the availability of DSCdecoder is not to be construed as an incitement to commit any unlawful act. It is for use only in those states and regions where such use is permitted.