On Monday, September 05, 2011 20:01:29 Durk Talsma wrote: > > I'm a little pressed for time this week, so I have to keep my response a > little on the short side. In essence, I think that this would be any > extremely cool feature to have. Do you already have a working copy that > you would consider merging with flightgear/next? If so, I would like to do > so and give it a shot (after having tried it locally and after ensuring > that everything works okay). > > So far, I only have one humble request, which is an option to conditionally > disable it. Although I haven't really had the need to listen to distant > stations yet, I can imagine that certain situations will arise where I > need to be able to follow ATC messages across larger distances. Given that > during the development cycle I would rather concentrate on debugging than > on deciphering a radio message, I think that an option to conditionally > disable ATC signal attenuation would be very welcome. > > > Cheers, > Durk
Hi Durk, Yes I have it working, you can test it by cloning locally g...@gitorious.org:~kantooon/fg/kantooons-flightgear.git and building branch radio-att. To test, you need a) an airport with ground traffic when you start and b) some hilly/mountainous terain arround that will affect the signal. Given the fact that I don't have a signal strength instrument, I am printing to stderr various information about the signal. The code does make a difference between ground transmissions and aircraft transmissions, so don't be surprised if you can hear tower and can't hear the aircraft on ground. In the future, I would also like to differentiate radio equipment in large aircraft from small, portable, airband transceivers you can find on light craft. If any of you guys that are also pilots can provide me with ERP values for various types of transceivers, including ATC ones, this would be also very useful, since I am basing my current values on some estimations. Since the model does 40 MHz to 20 GHz, calculations for frequencies out of the civilian VHF airband will yield different results, including military airband and radar (establishing a link budget for a radar emission is a whole different issue though). It also can account for the type of terrain underneath (based on surface impedance values). It would be useless though for shortwave SSB radio, since propagation at those frequencies is different. However, in the current state it's kind of a hack job, being on top of FGATCController and all. As Torsten and Martin have mentioned, there could be multiple uses for this, navradio, voice comms etc., so I think making this a stand-alone radio subsystem is a must. I have started doing just that, but I still need suggestions from you on how to integrate this with the rest of the code. So far, I think exposing a receive_text() function to the ATC system, callable with the position of the sender, frequency used, message string, and type of transmission would cover the ATC/AI territory. This would be complemented with a transmit_text() for the pilot->ATC interaction. As far as disabling/enabling it, should probably be enabled by a switch like realistic radio on/off. Still regarding radio and ATC, I have a problem with the AI being told to switch to an arbitrary number freq by Ground after startup. After digging around, I had found what seems like an out-of-bounds array reading in dynamics.cxx : https://gitorious.org/~kantooon/fg/kantooons- flightgear/commit/c69c91769e15d550d8cff48aec09edbd2a562e7a This seems to happen when the airport has only one ground frequency. Could you please verify that my patch is correct? Cheers, Adrian ------------------------------------------------------------------------------ Special Offer -- Download ArcSight Logger for FREE! Finally, a world-class log management solution at an even better price-free! And you'll get a free "Love Thy Logs" t-shirt when you download Logger. Secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsisghtdev2dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
