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VHF/DSC AIS and GPS
Thank You all, for the precious information put here. I had browsed
all of them and I am now impressed on the already many software and equipment designed to support AIS in the leisure boat market. At the begin my focus was only on the GpsMap276C NMEA interface with the ICOM ICM-602 VHF/DSC radio for position report, but now I think that AIS is the future, and the probably, would be the next wave of electronics for small boats, since it is based on gps and is more cheap and less hungry on 12V power than a traditional radar. I was very impressed on the Freeware software SeaClear, wich already has AIS support: I had just downloaded and installed it, but I think it could be one of the best softwares I have tried, mainly in the NMEA processing functions wich are exceeding and very good. The SeaPro is fantastic, and I compare it only with MaxSea. Thinking in small sailboats boats only, an integrated solution using a VHF/DSC radio (similar of ICM602) having all AIS channels frequency receiver allowing it to receive the AIS messages , talking over NMEA In/Out with a Gps/Chart Plotter (similar to a GpsMap276C) could be a more affordable solution and perhaps can be available not so long in the future, I hope. Thank You all again an best regards Pascal Goncalves |
"Pascal Goncalves" wrote in message om... Thank You all, for the precious information put here. I had browsed all of them and I am now impressed on the already many software and equipment designed to support AIS in the leisure boat market. At the begin my focus was only on the GpsMap276C NMEA interface with the ICOM ICM-602 VHF/DSC radio for position report, but now I think that AIS is the future, and the probably, would be the next wave of electronics for small boats, since it is based on gps and is more cheap and less hungry on 12V power than a traditional radar. I was very impressed on the Freeware software SeaClear, wich already has AIS support: I had just downloaded and installed it, but I think it could be one of the best softwares I have tried, mainly in the NMEA processing functions wich are exceeding and very good. The SeaPro is fantastic, and I compare it only with MaxSea. Thinking in small sailboats boats only, an integrated solution using a VHF/DSC radio (similar of ICM602) having all AIS channels frequency receiver allowing it to receive the AIS messages , talking over NMEA In/Out with a Gps/Chart Plotter (similar to a GpsMap276C) could be a more affordable solution and perhaps can be available not so long in the future, I hope. Thank You all again an best regards Pascal Goncalves The need for radar and AIS or GPS are independent. There will never be any such system that allows one to proceed without radar...that is if one wishes to be reasonably safe. Such systems complement but do not replace each other. Jim Donohue |
" The need for radar and AIS or GPS are independent. There will never be any such system that allows one to proceed without radar...that is if one wishes to be reasonably safe. Such systems complement but do not replace each other. Jim Donohue The vast majority of small craft do not carry radar, but do have vhf and gps; so I can see that the addition of a cheap AIS receiver would complement the system very well. Crossing very busy shipping lanes, such as the English Channel, would be much safer if AIS positions were displayed. It would not be infallible but a considerable improvement. Regards Jeff |
Jeff wrote:
The vast majority of small craft do not carry radar, but do have vhf and gps; so I can see that the addition of a cheap AIS receiver would complement the system very well. Shipplotter works very well. www.shipplotter.com |
In article uizee.10841$fI.3803@fed1read05,
"Jim Donohue" wrote: The need for radar and AIS or GPS are independent. There will never be any such system that allows one to proceed without radar...that is if one wishes to be reasonably safe. Such systems complement but do not replace each other. Jim Donohue In this day and age of GPS, AIS, and modern Marine Electronics, Radar is used to keep you from bumping into things that move around and do not advertise themselves in any other electronic way. It isn't used for position fixing like it was back 40 years ago, that is now done with GPS, or Loran C. Radar tells you where the logs and other hazards are, with one of those hazards being vessels that are operating with Radar. Bruce in alaska -- add a 2 before @ |
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JK escreveu: Jeff wrote: The vast majority of small craft do not carry radar, but do have vhf and gps; so I can see that the addition of a cheap AIS receiver would complement the system very well. Shipplotter works very well. www.shipplotter.com I agree with you 100%. After reading the several information about AIS, including the already available hardware (cheap AIS receivers) and softwares (including several very cheap and/or free) I am thinking that the recently introduced DSC function of the newest Garmin marine gps models like the Map276C/Map3006/Map3010 will be or are already totally obsoleted, because AIS is and will be the standard, as it is many more times usefull. I hope Garmin wakeup fast to change that obsolete DSC function in a more advanced and usefull AIS function, in these gps models. |
" I agree with you 100%. After reading the several information about AIS, including the already available hardware (cheap AIS receivers) and softwares (including several very cheap and/or free) I am thinking that the recently introduced DSC function of the newest Garmin marine gps models like the Map276C/Map3006/Map3010 will be or are already totally obsoleted, because AIS is and will be the standard, as it is many more times usefull. I hope Garmin wakeup fast to change that obsolete DSC function in a more advanced and usefull AIS function, in these gps models. DSC will not be obsolete, it performs a completely different function to AIS; that of alerting other stations of DISTRESS and calling specific stations. Routine position reports are not sent by DSC, its name, Digital selective Calling really says it all. As far as being obsolete on gps receivers; would you not like the position of a vessel in distress shown on your electronic chart? Adding the position of vessels transmitting AIS positions would be a huge advantage, but really you need both functions. I doubt if AIS will ever replace DSC for calling distress working, those functions are not included in the protocol, and the channel occupancy can be too high for reliable distress working; not to mention that DSC is used not only on VHF, but MF and HF as well. Regards Jeff |
On Wed, 11 May 2005 08:40:34 +0100, "Jeff" wrote:
I doubt if AIS will ever replace DSC for calling distress working, those functions are not included in the protocol, and the channel occupancy can be too high for reliable distress working It's a pity though - to have distress transmissions included in AIS would be very useful would only require another message number to be added (although it would mean a hell of a lot of firmware upgrades around the world!) Is channel occupancy really that much of a problem? I've been looking at data from around some of the busiest shipping lanes in the world, and there still seems to be plenty of capacity. Dave The email address used for sending these postings is not valid. All replies to the group please. |
Ok Jeff,
I agree that the distress function of the RADIO using DSC is important, but for this, any gps can send the position of my boat to the radio, so that the mayday buttom works. I was saying that the polling function of the radio, for position report on my gpsmap276c is much less usefull than a AIS function. The position report can tell me the position of others boat only when ruested by the polling function, so I must know the mssi code of the boat; I think this can be usefull to a flotilla cruising or maybe to fishing boats, or a race comitee. To have the position of a mayday boat in the gps ploter is not so usefull, because it is rare fact, and a sailboat or any leisure boat has little to do an a mayday function, contrary to ships or CG duties. The AIS main value from a sailboat perspective is Colision avoidance, and in this regard, a AIS transponder with a AIS receiver would be better, but a AIS receiver only would be vey usefull . Concluding, I think that the ideal solution would be a VHF/DSC/AIS ready radio, wich could receive the AIS signal of all ships for colision avoidance using litlle 12 V charge, but in a danger situation, I could activate the transmit function to send automactic to all ships my position (uses more 12V). The AIS NMEA message received could be send to my Gps/Ploter wich would plots the ships position etc, like others softwares does (ShipPloting, SeaClear, MaxSea, SeaPro etc), and providing other important information like CPA/TCPA etc. Regards Pascal |
"Pascal" wrote in message oups.com... Ok Jeff, I agree that the distress function of the RADIO using DSC is important, but for this, any gps can send the position of my boat to the radio, so that the mayday buttom works. I was saying that the polling function of the radio, for position report on my gpsmap276c is much less usefull than a AIS function. The position report can tell me the position of others boat only when ruested by the polling function, so I must know the mssi code of the boat; I think this can be usefull to a flotilla cruising or maybe to fishing boats, or a race comitee. To have the position of a mayday boat in the gps ploter is not so usefull, because it is rare fact, and a sailboat or any leisure boat has little to do an a mayday function, contrary to ships or CG duties. The AIS main value from a sailboat perspective is Colision avoidance, and in this regard, a AIS transponder with a AIS receiver would be better, but a AIS receiver only would be vey usefull . Concluding, I think that the ideal solution would be a VHF/DSC/AIS ready radio, wich could receive the AIS signal of all ships for colision avoidance using litlle 12 V charge, but in a danger situation, I could activate the transmit function to send automactic to all ships my position (uses more 12V). The AIS NMEA message received could be send to my Gps/Ploter wich would plots the ships position etc, like others softwares does (ShipPloting, SeaClear, MaxSea, SeaPro etc), and providing other important information like CPA/TCPA etc. Regards Pascal IMO will not allow AIS and ARPA on the same screen, so some larger commercial radar displays now are on the market with a switch to toggle between ARPA and AIS. These same units sometimes are sometimes available for non-IMO vessels allowing simultaneous ARPA and AIS on the screen. Adding DSC on the same screen would probably not be a smart idea due to clutter. Putting it on a separate chart plotter that polls the DSC VHF and HF radios sounds better to me. 73 Doug K7ABX |
Thank You all,
We here (Salvador/BA-Brazil) are trying to understand a bit more about AIS. I have instaled the Sea Clear free program and I was surprised to see that it is a very good program, suporting AIS and using the G7ToWin for download/upload, can use BSB and scanned charts (we have the OziExplorer from many years). A friend here had instaled the Ship Plotter demo software and made a test with his Icom Ham Radio and it worked very well: he gets about 20 ships here in Salvador/BA using a VHF antena instaled in the roof of his apartment building (very high) and plotted ships up to 20 nm from his home. The Ship Plotter sends information to Ozi (we do not know how) wich displays the ships as Map Features. We are having trouble in making it works with a standard marine VHF reciever, so he is buying a NASA black box Receiver for his boat and will use it with his laptop and Sea Clear. In my turn, I have a laptop too, with several othres navigation softwares but I think that it is a cumbersome thing in my boat, so I am waiting that Garmin unveils soon the AIS function for my GpsMap276C, or I will buy the NASA stand alone AIS. If the NASA with display would have a NMEA out interface too, like the black box model, so I could use it as well with the laptop too, I would have already buy it now. In another forum (discution list) someone made the folowing coment to my entry: " Then I think you schould start reading again." "All DCS capable Garmin receivers are also AIS capable. DCS is still the most wideley spread system, and AIS does not add anything to Garmin GPS receivers over the DCS system." "You can easely combine a Garmin with DCS with a AIS reciever since the data send to the (external) gps is exactly the same." This make me think that, maybe Garmin is developing the 3006/3010/276C software for AIS support and the Garmin Network could receive another Garmin "sensor" member: a black box AIS receiver wich could be a AIS receiver only (GAR20?) for the poor and a AIS receiver/transponder (GAR40?) for the rich. Off course, this is my pure speculation, and dream ... Regards Pascal S 13 00/W 038 27 |
On 13 May 2005 17:29:21 -0700, "Pascal" wrote:
In my turn, I have a laptop too, with several othres navigation softwares but I think that it is a cumbersome thing in my boat, so I am waiting that Garmin unveils soon the AIS function for my GpsMap276C, or I will buy the NASA stand alone AIS. Personally I doubt that you will see AIS for the 276C. Where I live there are often hundreds of vessels within AIS range, so we are talking a few updates per second - I don't think the 276C processor could keep up with that. In fact some dedicated AIS units can't keep up with it! I was on a ship in Singapore last year & the captain showed me that on his AIS transceiver (Saab I think), if he expanded the scale to 25nm the whole transceiver would reboot as it tried to draw all the vessels in range & crashed. Dave The email address used for sending these postings is not valid. All replies to the group please. |
Thanks Dave, but them I would ask You: and the NASA stand alone
"radar", or the NASA "engine"; can it support the AIS trafic? Do you think it has a much faster processor then the 276C? Regards Pascal |
Realy very haevy trafic, here it is many times small than this. I think
this will be a big problem for AIS in the future anyway. But, reading the NASA AIS radar user manual, I found that it has several options to setup the equipment in addition to the range settings. AIS radar operation has several limitation like: a) It can track up to 24 ships. If there is more, it displays only the 24 more proximity b) Plots only the 16 last track points of each ship NASA AIS radar can be customized by the user which can set the update rate to 8, 15, 30 or 60 sec. I believe that this limitations and controls can tune the operation in regard to speed/power of the processor. What do you think about? Maybe Garmin can include this setings in the GpsMap276C AIS function. As you can see, I am crazy to use the AIS in my boat, and I would acept any restrictions wich could be need to get it on my Gpsmap276C. Best Regards Pascal |
On 14 May 2005 05:19:40 -0700, "Pascal" wrote:
Thanks Dave, but them I would ask You: and the NASA stand alone "radar", or the NASA "engine"; can it support the AIS trafic? Do you think it has a much faster processor then the 276C? Well, it's (NASA radar) got a crappier display, with no colour & no maps, so it doesn't have anything else to do except decode & display boat positions. However, the 276C is already pretty busy with it's large/huge colour maps to be processed, GPS to be taken care of, etc. From my use of the 276C for the past year(?) & extensive use & programming of AIS systems, I'd say the 276C doesn't have enough processor power left to handle any serious AIS requirement. NASA engine only has to decode & output AIS via serial output, so it doesn't need to be that fast - it's only a single task. Dave The email address used for sending these postings is not valid. All replies to the group please. |
On 14 May 2005 06:31:15 -0700, "Pascal" wrote:
Realy very haevy trafic, here it is many times small than this. Possibly, but it mightn't always be that way, and manufacturers who build equipment for best case scenario instead of worst case won't last long anyway. AIS radar operation has several limitation like: a) It can track up to 24 ships. If there is more, it displays only the 24 more proximity Sounds dodgy to me - what if there are 24 stationary ships around you & 1 damn fast ferry coming straight at you? Will it swap over to the important one quick enough for you to do anything about it? NASA AIS radar can be customized by the user which can set the update rate to 8, 15, 30 or 60 sec. Too slow for real-life - AIS transmitters on boats going fast & turning fast tx at 2 second intervals (1 second if in assigned mode & assigned to 1 second), so if you have your receiver set to 60 seconds then you could be run over before you notice it. I believe that this limitations and controls can tune the operation in regard to speed/power of the processor. Sounds to me more like they make it into a useless toy. AIS is specifically designed for collision avoidance (though it has been hijacked for homeland security) & a lot of thought has been put into how many ships should be processed, how often boats should transmit, etc. All these limitations make it dangerous if someone hooks up a NASA radar & thinks that this is going to save them from having to keep a good watch. What do you think about? Maybe Garmin can include this setings in the GpsMap276C AIS function. As you can see, I am crazy to use the AIS in my boat, and I would acept any restrictions wich could be need to get it on my Gpsmap276C. If you really wanted to do it, you could get an AIS receiver, hook in a computer, re-code the AIS digital signals to DSC digital signals & feed to the 276C. However, I don't think this is something that Garmin should be tackling as - it takes a LOT of processor power, and how is AIS going to look on such a small display anyway? It will be far too cluttered. Here are some screen dumps from AIS around my area - as you can see, the screens are fairly cluttered even on a 1024x768 screen. http://www.jodael.com/sr162_performance_testing.htm Cheapest solution for the moment is an old notebook, free software, and an AIS receiver like the SR162 (or NASA engine though I prefer dual-channel receiver). If you have a notebook lying around you could be up & running with AIS display for US$300 or so. Dave The email address used for sending these postings is not valid. All replies to the group please. |
Thank You again Dave,
I have see the atached link document of the tests you had made, and really, there is a lot o ships there. I bacame very disapointed with your conclusion about the lack of possibility of AIS in 276C. In relity I am very disapointed with my Map276C. It has features I ado not use, like the automotive routing/nav, the fishfinder function with the GSD20, wich I will never would buy, the DSC function wich is useless, and with the problem os lack some NMEA messages (BWC/XTE) wich cause me a big problem with the autopilot, so I must use the old Map76 and Map130 for the AP. If the Map276C could not have AIS as you said, so I will sell it and buy another thing. I alredy have a old laptop and many chart ploter programs and many charts, and maybe I must change my position about the use of a PC in my boat. Thank you for your advise and best regards Pascal |
On 14 May 2005 19:27:15 -0700, "Pascal" wrote:
If the Map276C could not have AIS as you said, so I will sell it and buy another thing. Note that I don't work from Garmin! :-) I alredy have a old laptop and many chart ploter programs and many charts, and maybe I must change my position about the use of a PC in my boat. Sounds like you have plenty of reason to use one, so with the addition of a US$200 NASA or US$600 SR162 receiver you could have yourself a decent AIS display. Or wait a few months longer & AIS Class B transceivers will be out, and you can display other boat positions on your PC while transmitting your own position at the same time. Dave The email address used for sending these postings is not valid. All replies to the group please. |
Than You Dave,
Next week I will try a test with my laptop and the shipplotter software using a small VHF wich has 87/88 channels and connection to my pc sound input. The NASA could be a beter solution using the Sea Clear, but I will wait my friend's test when his NASA engine arrives nex month, before making a decision. Besta Regards Pascal |
Hi Dave,
I found that Si-Tex sell the NASA AIS radar and the Nasa AIS Engine with theyr Logo Mark. And more, they newer Color Gps Chart Plotters (Gps with 18 chanels) supoorts the NASA (Si-tex) AIS Engine and displays the ships in the C-Map Color Charts, exactly what I would like to have in my Garmin GpsMap276C. They are the first leisure Chart Ploters to support AIS, I think, but probaly in the hig end price class. Regards Pascal |
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