Marine

Click the name of a signal to see more detailed information, possible decoding, and additional sound and waterfall samples

Signal Name	Description	Frequency	Mode	Modulation	Bandwidth	Location	Sample Audio	Waterfall image
ARQ-M2-242	ARQAutomatic Repeat reQuestAutomatic Repeat Query-M2-242 (Also known as TDM 242, TDM-2, 96-TDM, and ARQAutomatic Repeat reQuestAutomatic Repeat Query-28) is a two-channel time division multiplexed telex system. This is the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 242 standard version. Used in Aeronautical, Marine, and Point-to-Point services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ-M2-342	ARQAutomatic Repeat reQuestAutomatic Repeat Query-M2-342 (Also known as TDM 342, TDM-2, 96-TDM, and ARQAutomatic Repeat reQuestAutomatic Repeat Query-28) is a two-channel time division multiplexed telex system. This is the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 342 standard version. Used in Aeronautical, Maritime, and Point-to-Point services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ-M4-242	ARQAutomatic Repeat reQuestAutomatic Repeat Query-M4-242 (Also known as TDM 242, TDM-4, 192-TDM, and ARQAutomatic Repeat reQuestAutomatic Repeat Query-56) is a four-channel time division multiplexed telex system. This is the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 242 standard version. Used in Aeronautical, Maritime, and Point-to-Point services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	250 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ-M4-342	ARQAutomatic Repeat reQuestAutomatic Repeat Query-M4-342 (Also known as TDM 342, TDM-4, 192-TDM, and ARQAutomatic Repeat reQuestAutomatic Repeat Query-56) is a four-channel time division multiplexed telex system. This is the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 342 standard version. Used in Aeronautical, Maritime, and Point-to-Point services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Automatic Identification System (AIS)	Automatic Identification System (AIS) is used by ships to broadcast position and vessel information.	161.975 MHzMegaHertz (MHz) 10^6 Hz — 162.025 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation	GMSKGaussian Minimum-Shift Keying	25 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Automatic Transmitter Identification System (ATIS)	ATIS systems are identification tags used by inland commercial waterway traffic on rivers in Europe. The FSKFrequency-Shift Keying burst is appended at the end of every voice transmission by the vessel operator.	30 MHzMegaHertz (MHz) 10^6 Hz — 800 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation	FSKFrequency-Shift Keying	12 kHzKiloHertz (kHz) 10^3 Hz	Europe
CODAR	CODAR (Coastal Ocean Dynamics Applications Radar) is used for near-surface ocean monitoring, such as waves and water current.	4.438 MHzMegaHertz (MHz) 10^6 Hz — 42.5 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	ILFM	50 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
CRY2001 Voice Scrambler	CRY2001 is a voice scrambling mode used on Sailor CRY2001 Scramblers. Fisherman often use these modes to communicate with privacy.	3 MHzMegaHertz (MHz) 10^6 Hz — 300 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	3 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Datawell Buoy HF Link	Datawell Buoy HFHigh Frequency (3-30 MHz) Links transmitted by Datawell Marine measurement buoys, measuring ocean conditions, temperature, and wave current.	25.5 MHzMegaHertz (MHz) 10^6 Hz — 45 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying, MFSKMultiple Frequency Shift-Keying	200 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
DeltaFix	DeltaFix was a DGPS system that was used to provide precision positioning used in the survey and oceanographic industry.	1.7 MHzMegaHertz (MHz) 10^6 Hz — 3.4 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	250 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Distress Radiobeacon (Analog)	Analog Distress Radiobeacons are simple siren-based transmitters that were installed in older EPIRB's, PLB's and ELT's. Currently used as a supplementary homing signal in modern digital radiobeacons.	121.5 MHzMegaHertz (MHz) 10^6 Hz — 243 MHzMegaHertz (MHz) 10^6 Hz	AMAmplitude Modulation	AMAmplitude Modulation	10 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Distress Radiobeacon (Digital)	Digital Distress Radiobeacons (EPIRB's, PLB's and ELT's) are emergency radio beacons used for search and rescue operations to locate a vessel, plane, or person in distress.	406 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation	PSKPhase-Shift Keying	1.4 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Driftnet Buoy Radio Beacon	Driftnet Radio Buoys are extensively used by fishing boats operating in open seas and oceans for collecting long fishing lines or fishing nets, with the assistance of a radio direction finder	1.6 MHzMegaHertz (MHz) 10^6 Hz — 28 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	OOKOn-Off Keying Modulation	1 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
GMDSS Digital Selective Calling	Global Maritime Distress and Safety System's Digital Selective Calling (GMDSS-DSC) is a maritime communication protocol intended to initiate ship-to-ship, ship-to-shore and shore-to-ship radiotelephone and MFMedium Frequency (300-3000 kHz)/HFHigh Frequency (3-30 MHz) radiotelex calls.	2.177 MHzMegaHertz (MHz) 10^6 Hz — 156.525 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	350 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Globe Wireless HF Network	Globe Wireless' Maritime Digital Radio was a system of 24 stations around the globe offering data services to large cargo vessels. Since 2014, GW has discontinued their HFHigh Frequency (3-30 MHz) network.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying, FSKFrequency-Shift Keying, OFDMOrthogonal Frequency-Division Multiplexing	400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 2 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
HyperFix	HyperFix was a radio-navigation system developed by Racal. Was used by vessels and ships. Has largely been phased out in favor of Differential GPS.	1.6 MHzMegaHertz (MHz) 10^6 Hz — 3.4 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)		250 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Inmarsat IsatM2M	IsatM2M Service operated by Inmarsat on existing Inmarsat-D/D+ infrastructure.	1,525 MHzMegaHertz (MHz) 10^6 Hz — 1,559 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	MFSKMultiple Frequency Shift-Keying	1.024 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Inmarsat-C TDM	Inmarsat C provides two-way data and messaging communication services to and from virtually anywhere in the world. The low-cost terminals and antennas are small enough to be fitted to any size of ship.	1,537.7 MHzMegaHertz (MHz) 10^6 Hz — 1,539.685 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying	2.5 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Inmarsat-D(D+) Downlink	Inmarsat D+ (and it's predecessor, Inmarsat D) was Inmarsat's satellite paging system. The main use of the technology was in tracking trucks and buoys and SCADA applications.	1,525 MHzMegaHertz (MHz) 10^6 Hz — 1,559 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	MFSKMultiple Frequency Shift-Keying	640 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
LORAN	LORAN (short for LOng RAnge Navigation) is a hyperbolic radio navigation system.	100 kHzKiloHertz (kHz) 10^3 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PPMPulse Position Modulation	20 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
SAS/SRC	Swedish navy transmitter for submarine communication. It shares the antenna with SAQ (Grimeton Radio)	40.4 kHzKiloHertz (kHz) 10^3 Hz		MSKMinimum-Shift Keying (When Shift/Bd = 0.5. It is impossible to get this ratio to be lower than 0.5, hence it is called the 'Minimum' shift.)		Sweden
SAS2	Swedish navy transmitter for submarine communication. It shares the antenna with SAQ (Grimeton Radio) and is activated less often as the other Swedish transmitters used for VLFVery Low Frequency (3-30 kHz) submarine communication. Usually, it works with reduced power.	42.5 kHzKiloHertz (kHz) 10^3 Hz		MSKMinimum-Shift Keying (When Shift/Bd = 0.5. It is impossible to get this ratio to be lower than 0.5, hence it is called the 'Minimum' shift.)		Sweden
SAS3	Swedish navy transmitter for submarine communication. It shares the antenna with SAQ (Grimeton Radio).	44.2 kHzKiloHertz (kHz) 10^3 Hz		MSKMinimum-Shift Keying (When Shift/Bd = 0.5. It is impossible to get this ratio to be lower than 0.5, hence it is called the 'Minimum' shift.)		Sweden
SHR	Swedish navy transmitter for submarine communication. It shares the antenna with SAQ (Grimeton Radio).	38 kHzKiloHertz (kHz) 10^3 Hz		MSKMinimum-Shift Keying (When Shift/Bd = 0.5. It is impossible to get this ratio to be lower than 0.5, hence it is called the 'Minimum' shift.)		Sweden
SITOR-A	SITOR-A (Also known as AMTOR-A) is one of two modes of SITOR, which stands for Simplex Teletype Over Radio.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	350 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
SITOR-B	SITOR-B is one of two modes of SITOR (Simplex Teletype Over Radio).	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	350 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Sonne	Sonne (Called Consol by the Britons) was a low-frequency radio range based radio navigation system used for long range navigation.	250 kHzKiloHertz (kHz) 10^3 Hz — 350 kHzKiloHertz (kHz) 10^3 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	OOKOn-Off Keying Modulation	1 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
WLO			AMAmplitude Modulation	CWContinuous Wave	1 kHzKiloHertz (kHz) 10^3 Hz	United States