AUTOMATIC IDENTIFICATION SYSTEM ( AIS ) / DIGITAL SELECTIVE CALLING (DSC )

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AIS OPERATES ON 161.975 MHz AND 162.025 MHz ( CHANNELS 87 & 88, WITHIN THE MARINE VHF SERVICE ) ITS PART OF THE WORLD WIDE MARITIME SAFETY SYSTEM, PACKETS OF DATA ARE SENT BY THE VESSELS GIVING THEIR CALLSIGN,POSITION,COURSE AND DESTINATION ETC TO OTHER SUITABLY EQUIPPED VESSELS. SINCE DECEMBER 2004 ALL VESSELS OVER 300 TONS ARE COMPULSORILY FITTED WITH AIS.TO RECEIVE SUCH DATA ALL THAT IS REQUIRED IS A SCANNER RECEIVER, COVERING THE MARINE VHF BANDS AND SOME SOFTWARE. IMPROVED RECEPTION WILL BE ACHIEVED IF THE SIGNAL FROM THE SCANNER RECEIVER IS TAKEN FROM THE DISCRIMINATOR OUTPUT.ONE THING TO BEAR IN MIND IS THE EXPECTED RANGE OF THIS SYSTEM, IF THE NEAREST BIT OF OCEAN OR ESTUARY IS 200 MILES AWAY, FORGET IT AS VHF WILL NOT COVER THAT DISTANCE, EXCEPT IN EXCEPTIONAL CONDITIONS. ANOTHER BIT OF SOFTWARE IS DSC DECODER ,IT WILL DECODE NAVTEX MESSAGES AND H.F. AND VHF DSC ( DIGITAL SELECTIVE CALLING MESSAGES) IT WILL DISPLAY THE SOURCE ON A CHART.SHIP PLOTTER CHARTS ARE COMPATIABLE WITH THIS SOFTWARE ALSO.THE VHF DSC FREQUENCY IS CHANNEL 70 - 156.525 MHZ.

SOFTWARE

MODEM

DOWNLOAD SITE

SHIPPLOTTER

SOUND CARD

SHIP PLOTTER

DSC DECODER

SOUND CARD

DSCDECODER

DGPS

SOUND CARD

DGPS DECODER

AISMON

SOUND CARD

YAHOO

DGPS  BEACONS CAN BE FOUND BETWEEN 250 KHZ AND 350 KHZ,THEY HELP ADD ACCURRACY TO GPS POSITIONING.SEE THE DIAGRAM AT THE BOTTOM OF THIS PAGE.

FOR MORE DETAILED INFORMATION ON THE AIS SYSTEM PLEASE REFER TO THE BELOW LINKS :-

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http://www.navcen.uscg.gov/enav/ais/default.htm

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http://home.wxs.nl/~pa3esz/ais/index.html

TO CREATE YOUR OWN CUSTOMISED MAPS VISIT THE FOLLOWING SITE :

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http://www.sailwx.info/maps/shipplotter.phtml?width=800&height=600&lat=52&lon=2&radius=50

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http://emit.demon.co.uk/map2.

 


BELOW IS A LIST OF DSC ( DIGITAL SELECTIVE CALLING FREQUENCIES )

SHIP STATIONS

458.5
2177.0      2189.5
4208.0      4208.5    4209.0
6312.5      6313.0    6313.5
8415.0      8415.5    8416.0
12577.5   12578.0   12578.5
16805.0   16805.5   16806.0
18898.5   18899.0   18899.5
22374.5   22375.0   22375.5
25208.5   25209.0   25209.5

COAST STATIONS

455.5
2177.0
4219.5     4220.0    4220.5
6331.0     6331.5    6332.0
8436.5     8437.0    8437.5
12657.0  12657.5   12658.0
16903.0  16903.5   16904.0
19703.5  19704.0   19704.5
22444.0  22444.5   22445.0
26121.0  26121.5   26122.0

THE FOLLOWING ARE SHIP FREQUENCIES PAIRED WITH COAST STATION FREQUENCIES,AND THESE ARE "FIRST CHOICE DSC " FREQUENCIES

4208.0 / 4219.5
6312.5 / 6331.0
8415.0 / 8436.5
12577.5 / 12657.0
16805.0 / 16903.0
18898.5 / 19703.5
22374.5 / 22444.0
25208.5 / 26121.0



2177.0 KHZ IS RESERVED FOR SHIP TO SHIP CALLING ONLY

156.525 MHZ.CHANNEL 70 VHF DSC

A DISTRESS ALERT IS SENT ON THE DSC CHANNEL,BUT THE ACTUAL TFC IS CONDUCTED ON A RT OR NBDP FREQUENCY


TUNING  DSC SIGNALS

THE DCS DE-CODER PROGRAMME REQUIRES A DECENT RECEIVER.ON MF/H.F. WITH USB SELECTED TUNE ABOUT 1700 HZ BELOW THE DESIGNATED FREQUENCY, WITH LSB SELECTED TUNE 1700 HZ ABOVE THE DESIGNATED FREQUENCY.ON VHF THE SYSTEM IS SLIGHTLY DIFFERENT, AND REQUIRES YOU JUST TO TUNE YOUR RECEIVER TO THE CORRECT FREQUENCY.FOR VHF DSC DECODING,THE SIGNAL SHOULD BE TAKEN FROM THER DISCRIMINATOR DIRECT TO THE PC LINE IN/MIC IN JACK SOCKET.A LOT OF RECEIVERS HAVE WHAT IS BECOMING A STANDARD SOCKET ON THE BACK WHICH YOU CAN CONNECT TO.SEE THE BELOW DIAGRAM.THE SHIPPLOTTER PROGRAM REALLY REQUIRES THE OUTPUT TAKEN FROM THE DISCRIMINATOR CLICK HERE FOR FURTHER INFORMATION.

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WHATS A MF/HF DSC SIGNAL SOUND LIKE? CLICK HERE


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A VIEW OF AVONMOUTH / ROYAL PORTBURY / PORTISHEAD DOCKS - INPUT FROM SHIP PLOTTER

 


BRISTOL CHANNEL MARINE VHF CHANNELS

IF YOU HAVE A SPARE RECEIVER,USE IT TO MONITOR YOUR LOCAL VTS/TUG/VESSELS ON VHF AS WELL AS WATCHING THEM BEING PLOTTED ON YOUR SHIPPLOTTER CHARTS. 

CHANNEL 6 INTERSHIP
CHANNEL 8 TUG / SHIP
CHANNEL 9 AVONMOUTH RADIO
CHANNEL 10 TUG
CHANNEL 11 BRISTOL CITY DOCKS
CHANNEL 12 BRISTOL VTS
CHANNEL 13 SWANSEA/SHARPNESS/....ALSO BRIDGE COMMUNICATIONS
CHANNEL 14 SWANSEA/AVONMOUTH PORT OPERATIONS/BRISTOL CITY DOCKS
CHANNEL 16 CALLING ETC
CHANNEL 12/14/16 ROYAL PORTBURY DOCK RADIO
CHANNEL 17 SHARPNESS PIERHEAD
CHANNEL 18 CARDIFF
CHANNEL 23 SWANSEA/MILFORD HAVEN COASTGUARD
CHANNEL 37 MARINA CHANNEL
CHANNEL 67 ILFRACOMBE
CHANNEL 69 SERVERN  VTS/SWANSEA TUGS
CHANNEL 71 SWANSEA TUGS
CHANNEL 72 TUG / SHIP
CHANNEL 73 PRINCE STREET BRIDGE/NETHAM LOCKS/BRISTOL HARBOUR
CHANNEL 74 SHARPNESS BRIDGE
CHANNEL 80 PORTISHEAD MARINA/BRISTOL MARINA
CHANNEL 86 SWANSEA/MILFORD HAVEN COASTGUARD

 


SLIM JIM ANTENNA FOR 162 MHZ AIS RECEPTION

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DOES THE ABOVE ANTENNA WORK? ......AFTER USING IT FOR A COUPLE OF WEEKS AND COMPARING IT WITH A WHIP MOUNTED AT THE SAME HEIGHT, I HAVE TO SAY ITS A TREMENDOUS IMPROVEMENT. I WAS ONLY RECEIVING THE OCCASIONAL MESSAGE FROM SHIPS DOWN IN AVONMOUTH ( ABOUT 7 MILES AWAY,OVER A DIFFICULT PATH ) NOW I RECEIVE MESSAGES FROM SHIPS OUT IN THE BRISTOL CHANNEL TO A DISTANCE OF ABOUT 20 MILES.

HINT .. IF YOU ARE FEEDING AIS SIGNALS INTO THE SERIAL PORT ( USING THE EXCELLENT NASA A.I.S ENGINE FOR EXAMPLE ) REMEMBER ( DEPENDENT ON YOUR COMPUTER BEING FAIRLY "POWERFUL" )YOU COULD STILL RUN THE DSC PROGRAM AT THE SAME TIME WITH THE INPUT FROM YOUR RECEIVER FED INTO THE SOUNDCARD ......WINDOWS XP WILL ALSO SUPPORT MULTIPLE SOUND CARDS.


 

ROUGH IDEA HERE OF WHAT THE DGPS BEACONS ARE DOING

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TUNING CHART - SHOWING WHAT DGPS SIGNAL LOOKS LIKE

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