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
> 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
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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
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