Re: [Flightgear-devel] Real-time shipping traffic
Ok Stuart Sounds good, Ok on the ferries, nothing around can be said to move on water at high speed. I had not seen AIShub before so I had look, I see allow you to nominate an area for data sent from their server. They provide a binary send your off air data to direct to them, and allow their windows app to view it back from a port on their server. Thus to do much with it outside of that, you are back to rolling your own code. I did play around with the AI a while ago, but my butchered code would be way behind the development now. Firstly i was trying to get the AI and MP in sync over multiple machines doing the graphics. After that figure out how to put in the AIS ships and ADS-B aircraft. For MP I had one FG machine connect to the server, then echo the received server data stream to the 3 others to prevent 4 instances appearing on the MP server. That seemed to work ok. For AI aircraft, I exported the properties for all instances in one machine to the slaves so the AI planes appeared correctly in all windows. It was very messy, but worked ok till you went to Schipol and 100 plus AI aircraft started to slow things down. However at the time I think it might have been Durk said there might be a possibility of moving the AI into a separate sub-sytem in future. I need to go back and look at the current FG AI code. Its probably all different now. I thought a special version of the MP server might be the solution. but it became very complicated, and I am no programmer either. It seemed at the time, the FG AI had the capability to interpolate and predict the movements. With aircraft its bit easier because the ADS-B updates once a second, the AIS ships can be a couple of minutes apart. Probably the cause of your issue with the fast ferries. The other option was make a torn down core version of FG, just running the AI, and seeding it with AIS and ADS-B real time data. It would also handle MP data, Thus if the AI system generated a scheduled aircraft flight, and the real one appears on ADS-B, use the real data. This would all be supported with the live off air audio from a couple of receivers. All in al a nice realtime sim environment. Which ever way, It seemed the best thing was to run it all on a separate machine and just seed the FG machines with the AI marine and airborne items in total. If I just use my local AIS and ADS-B realtime data its not to much, but if you say 7000 ships, and i guess similar numbers of real aircraft in the air there is potentially a huge amount of processing involved. Normally at any given time here in Bali there no more than about 6 ships and 15 aircraft in range of my receivers. Like the marine AIS there are sites with Aircraft ADS-B data showing live traffic. I have also seen mention of live ATC comms being available as audio streams for some areas as well. There also an ADS-B data sharing site like the AIShub one you mentioned. http://www.adsbhub.net Like the AIS hub they allow you free use with their data as long as you have a receiver feeding to them. Some of the libraries here for sharing aircraft tracking data might also be of use for marine AIS data, but I have not checked them out as yet myself. http://www.libhomeradar.org/functions/index.html Harry On Fri, Mar 4, 2011 at 4:13 AM, Stuart Buchanan stuar...@gmail.com wrote: On Thu, Mar 3, 2011 at 8:45 AM, Harry Campigli wrote: Hello Stuart, Have you gone any further with your AIS scripting? I have. I've got a quite nice proxy and some very simple heuristics to make the ship movements seem realistic. Unfortunately they don't quite work with ships docking from high speed - in particular the ferries to Alcatraz end up quite out of sync. I haven't published the scripts as I've not had any response back from the people running the marinetraffic website. Their usage agreement is quite specific. I have 2 receivers, one AIS for marine and the other ADS-B for aircraft, I am planning on driving AI aircraft and ships with both Probably need some kind of proxy or relay server on them as well. Also there some processing steps required between the devices to decrypt the strings. I was thinking along the lines of a local MP server specially modified, to do a few special tasks here, but that could also feed both data streams back out to external public MP servers. For now I am still kicking around idea s on how best to tie it all together My thinking on this matches yours :). As you may be aware, AIS Hub (http://www.aishub.net/) allows people running an AIS receiver contribute, and more importantly receive, raw NMEA data. If you have an AIS receiver, you should be able to join the group, and receive worldwide data (well, where there is coverage). AFAICT there is no restriction on usage. With a feed of raw NMEA data, it should be fairly straightforward to modify the MP server to act as a proxy and push shipping information into the MP data
Re: [Flightgear-devel] Real-time shipping traffic
On Thu, Mar 3, 2011 at 8:45 AM, Harry Campigli wrote: Hello Stuart, Have you gone any further with your AIS scripting? I have. I've got a quite nice proxy and some very simple heuristics to make the ship movements seem realistic. Unfortunately they don't quite work with ships docking from high speed - in particular the ferries to Alcatraz end up quite out of sync. I haven't published the scripts as I've not had any response back from the people running the marinetraffic website. Their usage agreement is quite specific. I have 2 receivers, one AIS for marine and the other ADS-B for aircraft, I am planning on driving AI aircraft and ships with both Probably need some kind of proxy or relay server on them as well. Also there some processing steps required between the devices to decrypt the strings. I was thinking along the lines of a local MP server specially modified, to do a few special tasks here, but that could also feed both data streams back out to external public MP servers. For now I am still kicking around idea s on how best to tie it all together My thinking on this matches yours :). As you may be aware, AIS Hub (http://www.aishub.net/) allows people running an AIS receiver contribute, and more importantly receive, raw NMEA data. If you have an AIS receiver, you should be able to join the group, and receive worldwide data (well, where there is coverage). AFAICT there is no restriction on usage. With a feed of raw NMEA data, it should be fairly straightforward to modify the MP server to act as a proxy and push shipping information into the MP data network. IIRC we already have some NMEA protocol support in the FG core itself, though I haven't looked at it myself. There might be a bit of work required in the FG core to support MP ships, but that should be fairly easy to add. I have done some fairly trivial animation work taking the ship types and lengths provided by AIS and using them to select an appropriate ship model and scale it to the correct length. It works pretty well. My only concern is whether the MP servers can handle the load. There are around 7000 vessels being tracked on AISHub, which is rather more ships than we have aircraft! -Stuart -- What You Don't Know About Data Connectivity CAN Hurt You This paper provides an overview of data connectivity, details its effect on application quality, and explores various alternative solutions. http://p.sf.net/sfu/progress-d2d ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
[Flightgear-devel] Real-time shipping traffic
Hi All, I recently came across http://www.marinetraffic.com/, which tracks shipping by means of their AIS transmitter, which all vessels over 299 gross tonnes must carry. The data is transmitted by radio and includes position, speed, course, rate of turn, as well as the vessel type, dimensions etcs.. The project collects the data from various volunteer receivers and collates it into a DB, and provides mash-ups over Google maps etc. I think there could be a very nice little project to incorporate a data feed from their server through a proxy and into our MP network, displaying marine traffic in real-time. This would completely obviate the need for AI shipping routes, and at a stroke, the sea in FG would become accurately populated. Unlike aircraft transmitting ADS-B updates, shipping is quite slow slow and therefore has less of an interpolation problem, pluss it doesn't really need to interact with our aircraft*, so this seems a very good fit. Their tracking software is GPL, so one would hope that they would have some sympathy with us, plus it would provide a way for them to visualize their data. The only major downside I can see is that some ports are obviously very busy - a quick look at Antwerp showed over 1000 vessels in a 50nm radius. I guess this would have a significant impact on the MP protocol, However, on the plus side, the ship models themselves are very simple and wouldn't have any animations, so one would hope that the frame-rate hit would be reasonable. Anyone particularly interested in taking this further? I may look at it myself, and at least engage the people running the project, but don't expect any quick results! -Stuart * I guess technically a boat might have to give way to a seaplane, just as a motor vessel should give way to a sailboat. However I am reliably informed that size does matter in these cases :) -- The Next 800 Companies to Lead America's Growth: New Video Whitepaper David G. Thomson, author of the best-selling book Blueprint to a Billion shares his insights and actions to help propel your business during the next growth cycle. Listen Now! http://p.sf.net/sfu/SAP-dev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Real-time shipping traffic
Hello Stuart, Have you gone any further with your AIS scripting? I have 2 receivers, one AIS for marine and the other ADS-B for aircraft, I am planning on driving AI aircraft and ships with both Probably need some kind of proxy or relay server on them as well. Also there some processing steps required between the devices to decrypt the strings. I was thinking along the lines of a local MP server specially modified, to do a few special tasks here, but that could also feed both data streams back out to external public MP servers. For now I am still kicking around idea s on how best to tie it all together Harry On Mon, Jan 24, 2011 at 4:54 AM, Vivian Meazza vivian.mea...@lineone.netwrote: Stuart On Thu, Nov 4, 2010 at 11:32 AM, I wrote: Hi All, I recently came across http://www.marinetraffic.com/, which tracks shipping by means of their AIS transmitter, which all vessels over 299 gross tonnes must carry. The data is transmitted by radio and includes position, speed, course, rate of turn, as well as the vessel type, dimensions etcs.. The project collects the data from various volunteer receivers and collates it into a DB, and provides mash-ups over Google maps etc. I think there could be a very nice little project to incorporate a data feed from their server through a proxy and into our MP network, displaying marine traffic in real-time. This would completely obviate the need for AI shipping routes, and at a stroke, the sea in FG would become accurately populated. Having a bit of spare time over the weekend, I put together a pretty simple perl script to act as a proxy between the marinetraffic website and FlightGear. At a high level the proxy works as follows: 0) FG is pre-provisioned with 40 AI ships at start of day 1) The script gets the current aircraft position from the property system over the telnet interface 2) The script make an HTTP request to marinetraffic.com to get all the ships within a 1 degree x 1 degree square centred on the aircraft position. 3) For each of the ships, the script sets the type, position, speed and heading of an AI ship with the data using the telnet interface again. The resulting screenshot isn't particularly impressive, but it does look more realistic than the distribution and heading of the normal materials.xml random ships: http://www.nanjika.co.uk/flightgear/ships.jpg The screenshot shows a couple of container ships (one with a tug at the front which has the wrong model) making their way up the Firth of Forth near Edinburgh. In the distance you can just make out a ship berthed at Grangemouth. There are a couple of limitations with this approach - We have to pre-define the number of AI ships in an AI scenario. I've got 40 on my system, but I don't have a good feel for what the overhead of each AI ship is. If the script finds more than 40 ships when searching, it reduces the search area and tries again. It would be much easier if we could define AI objects at runtime. - The telnet interface is very slow. It takes a couple of minutes to read and write the various properties. - The current proxy causes a per-client load on the marinetraffic website. I've emailed for permission to use the data feed, but I doubt they'll be too happy if we were to integrate this into FG itself and have a couple thousand clients requesting data every couple of minutes. I think some approach which uses the raw NMEA data to get and then feeds it into the MP network would be better. Unfortunately its not clear how we can do that. - Close to shore, ships seem to change their course such that a snapshot of position, speed and heading every couple of minutes is insufficient so we get jumps with each update. I think a better model might be to use the data as a sequence of waypoints, but I haven't investigated to see how easy that would be to implement. I've emailed the marinetraffic website for permission to use the XML feeds that I've reverse engineered and to see if they are interested in helping us with some raw data. Once I've permission I'll put together a package with the proxy and the various other changes so people can have a play. That looks like very good work so far. Let's hope you can make more progress. The way ahead that you have outlined looks promising. Vivian -- Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net
Re: [Flightgear-devel] Real-time shipping traffic
I wouldn't mind pitching in on this, but as far as leading the project, or anything of that caliber, I probably don't have the time to organize such a task. However, I'm very interested in helping out with this effort, and may know of another soul as well. So whatever happens, please keep me informed. Wes On Thu, Nov 4, 2010 at 7:32 AM, Stuart Buchanan stuar...@gmail.com wrote: Hi All, I recently came across http://www.marinetraffic.com/, which tracks shipping by means of their AIS transmitter, which all vessels over 299 gross tonnes must carry. The data is transmitted by radio and includes position, speed, course, rate of turn, as well as the vessel type, dimensions etcs.. The project collects the data from various volunteer receivers and collates it into a DB, and provides mash-ups over Google maps etc. I think there could be a very nice little project to incorporate a data feed from their server through a proxy and into our MP network, displaying marine traffic in real-time. This would completely obviate the need for AI shipping routes, and at a stroke, the sea in FG would become accurately populated. Unlike aircraft transmitting ADS-B updates, shipping is quite slow slow and therefore has less of an interpolation problem, pluss it doesn't really need to interact with our aircraft*, so this seems a very good fit. Their tracking software is GPL, so one would hope that they would have some sympathy with us, plus it would provide a way for them to visualize their data. The only major downside I can see is that some ports are obviously very busy - a quick look at Antwerp showed over 1000 vessels in a 50nm radius. I guess this would have a significant impact on the MP protocol, However, on the plus side, the ship models themselves are very simple and wouldn't have any animations, so one would hope that the frame-rate hit would be reasonable. Anyone particularly interested in taking this further? I may look at it myself, and at least engage the people running the project, but don't expect any quick results! -Stuart * I guess technically a boat might have to give way to a seaplane, just as a motor vessel should give way to a sailboat. However I am reliably informed that size does matter in these cases :) -- The Next 800 Companies to Lead America's Growth: New Video Whitepaper David G. Thomson, author of the best-selling book Blueprint to a Billion shares his insights and actions to help propel your business during the next growth cycle. Listen Now! http://p.sf.net/sfu/SAP-dev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- -- The Next 800 Companies to Lead America's Growth: New Video Whitepaper David G. Thomson, author of the best-selling book Blueprint to a Billion shares his insights and actions to help propel your business during the next growth cycle. Listen Now! http://p.sf.net/sfu/SAP-dev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
