## Re: [Flightgear-devel] Groundspeed and MP radar

 Re: [Flightgear-devel] Groundspeed and MP radar From: John Denker - 2007-05-30 01:37:03 ```On 05/29/2007 08:06 PM, syd & sandy wrote: >> Well , Ive thought of that too .researching these things leads me to believe that in real life (I >> could be wrong),groundspeed is calculated using a nav signal as a reference point That's not right. Groundspeed is groundspeed. There's only one proper definition of groundspeed. An _approximation_ to groundspeed in terms of the rate of slant range made good to/from a navaid is sometimes encountered, for example in a _DME_ unit. This is considered a nonideality of the DME system, not a redefinition of groundspeed. This nonideality is never AFAIK exhibited by GPS or RADAR units. Every GPS and every RADAR I've ever seen or heard of, when asked to report groundspeed, reports honest-to-goodness groundspeed, independent of any route, independent of the relationship between the ground track and this-or-that navaid. > > , so it is only > > accurate if you are flying directly toward that point... But a /velocities/groundspeed could be > > used as a starting point ... It takes only a couple of lines of nasal to calculate the groundspeed in terms of the already-available properties. Hint: Aircraft/A-10/Nasal/aar.nas line 261 ... so I don't understand what the discussion is about. The Subject: line refers to groundspeed. If you want to ask about something else, perhaps about ETE or ETA at this-or-that station, then the answer might become route-dependent. (Different questions have different answers!) So: If there's a problem here that needs solving, please describe the problem more fully. ```

 [Flightgear-devel] For the - Author of Concorde - VIDEO of actual errors - Continued From: Forums Virgin Net - 2007-05-29 02:59:22 Attachments: Message as HTML ```04/ Further: As promised here is a video showing how the control surfaces act in = oposition to the commands sent to them! Download Link http://files.ww.com/files/33558.html (Web Browser Interface) http://files.ww.com/getfile.html/33558/1932104765/Concorde0911-error.divx= .avi (Download Video to HD) Current Progress of Concordes Flight During Instrument & system control = (AutoPilot) faults http://fgfs.i-net.hu/modules/fgtracker/?FUNCT=3DFLIGHT&FLIGHTID=3D13031 Concorde Instability errors from FlightGear.exe Concorde was not obeying control commands to the aileron's during the = missed approach and turning procedure before a final approach could be = made, it is shown in the Video I have made to demonstrate the control = surfaces were behaving erratically. During Descent - Also the sound failed on descent OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) Failed to generate audio source. OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) Failed to generate audio source. OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) Failed to generate audio source. Chat [Aerotro] Welcome to Aerotro Chat [Aerotro] this is version v0.9.11 Chat [Aerotro] using protocol version v1.1 Chat [Aerotro] AeroPLI is now online, using Chat [Aerotro] Aircraft/Concorde/Models/Concorde_ba.xml OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) Failed to generate audio source. OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) Failed to generate audio source. Chat [Aerotro] client 'mpdummy' has left OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) Failed to generate audio source. Regards, Aerotro Online FlightGear Simulator Tracker Page. http://mpserver04.flightgear.org http://www.flightgear.org```
 Re: [Flightgear-devel] For the - Author of Concorde - VIDEO of actual errors - Continued From: gh.robin - 2007-05-29 11:39:33 ```On Tue 29 May 2007 04:59, Forums Virgin Net wrote: > 04/ Further: > > As promised here is a video showing how the control surfaces act in > oposition to the commands sent to them! > > Download Link > http://files.ww.com/files/33558.html (Web Browser Interface) > http://files.ww.com/getfile.html/33558/1932104765/Concorde0911-error.divx= =2Ea >vi (Download Video to HD) > SNIP > OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) > Failed to generate audio source. > OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) > Failed to generate audio source. > Chat [Aerotro] client 'mpdummy' has left > > OpenAL error (AL_INVALID_VALUE): bind_source (alGenSources) > Failed to generate audio source. > > Regards, Aerotro > That good demonstrative Video, makes me to ask two opened questions and=20 remarks Don't we have some main modifications regarding the autopilot , from 0.9.10= to=20 0.9.11 pre1, which could explain that strange behaviour ? I did noticed mainly some malfunctions of the autopilot when using FG cvs H= EAD=20 branch, though seemed working when using PRE_OSG_PLIB_20061029, which don't= =20 mean it is fully working on that branch We have had modifications and improvements regarding Nasal, from 0.9.10 to= =20 0.9.11 pre1 =20 Concorde is using a lot of Nasal scripts. Does not these differences could explain that strange behaviour? That video shows that we have inconsistencies in the data when operating to= =20 land. Regards =2D-=20 G=E9rard ```
 [Flightgear-devel] Groundspeed and MP radar From: syd & sandy - 2007-05-29 19:23:16 ```Hi all , I would like to add a groundspeed property to the autopilot route manager ... the calculations are already done in the source code , I would just like to output that to a property for the Primus 1000 FMS mode.GPS has an indicated -groundspeed , but I would prefer to use the route-manager for this ... any objections /suggestions ? Im also trying to do a 2d radar panel , using the radar x-shift and y-shift , which of coarse need scaling ... can scaling use a property ? Ive had no luck so far... syd & sandy ```
 Re: [Flightgear-devel] Groundspeed and MP radar From: alexis bory - 2007-05-29 20:50:07 ```syd & sandy a e'crit : > Hi all , I would like to add a groundspeed property to the autopilot > route manager ... the calculations are already done in the source > code , I would just like to output that to a property for the Primus > 1000 FMS mode.GPS has an indicated -groundspeed , but I would prefer > to use the route-manager for this ... any objections /suggestions ? Why not in /velocities ? (I used a Nasal to get a ground speed, I'll be happy to get ride of it :) Alexis ```
 Re: [Flightgear-devel] Groundspeed and MP radar From: syd & sandy - 2007-05-30 00:07:23 ```On Tue, 29 May 2007 22:49:44 +0200 alexis bory wrote: > syd & sandy a e'crit : > > Hi all , I would like to add a groundspeed property to the autopilot > > route manager ... the calculations are already done in the source > > code , I would just like to output that to a property for the Primus > > 1000 FMS mode.GPS has an indicated -groundspeed , but I would prefer > > to use the route-manager for this ... any objections /suggestions ? > > Why not in /velocities ? > > > (I used a Nasal to get a ground speed, I'll be happy to get ride of it :) > > Alexis Well , Ive thought of that too .researching these things leads me to believe that in real life (I could be wrong),groundspeed is calculated using a nav signal as a reference point , so it is only accurate if you are flying directly toward that point... But a /velocities/groundspeed could be used as a starting point ... -- syd & sandy ```
 Re: [Flightgear-devel] Groundspeed and MP radar From: John Denker - 2007-05-30 01:37:03 ```On 05/29/2007 08:06 PM, syd & sandy wrote: >> Well , Ive thought of that too .researching these things leads me to believe that in real life (I >> could be wrong),groundspeed is calculated using a nav signal as a reference point That's not right. Groundspeed is groundspeed. There's only one proper definition of groundspeed. An _approximation_ to groundspeed in terms of the rate of slant range made good to/from a navaid is sometimes encountered, for example in a _DME_ unit. This is considered a nonideality of the DME system, not a redefinition of groundspeed. This nonideality is never AFAIK exhibited by GPS or RADAR units. Every GPS and every RADAR I've ever seen or heard of, when asked to report groundspeed, reports honest-to-goodness groundspeed, independent of any route, independent of the relationship between the ground track and this-or-that navaid. > > , so it is only > > accurate if you are flying directly toward that point... But a /velocities/groundspeed could be > > used as a starting point ... It takes only a couple of lines of nasal to calculate the groundspeed in terms of the already-available properties. Hint: Aircraft/A-10/Nasal/aar.nas line 261 ... so I don't understand what the discussion is about. The Subject: line refers to groundspeed. If you want to ask about something else, perhaps about ETE or ETA at this-or-that station, then the answer might become route-dependent. (Different questions have different answers!) So: If there's a problem here that needs solving, please describe the problem more fully. ```
 Re: [Flightgear-devel] Groundspeed and MP radar From: syd & sandy - 2007-05-30 02:19:52 ```On Tue, 29 May 2007 21:36:55 -0400 John Denker wrote: > On 05/29/2007 08:06 PM, syd & sandy wrote: > > >> Well , Ive thought of that too .researching these things leads me to believe that in real life (I > >> could be wrong),groundspeed is calculated using a nav signal as a reference point > > That's not right. > > Groundspeed is groundspeed. There's only one proper definition of > groundspeed. did you miss the (I could be wrong )?;) > > An _approximation_ to groundspeed in terms of the rate of slant range > made good to/from a navaid is sometimes encountered, for example in a > _DME_ unit. This is considered a nonideality of the DME system, not > a redefinition of groundspeed. > > This nonideality is never AFAIK exhibited by GPS or RADAR units. Every > GPS and every RADAR I've ever seen or heard of, when asked to report > groundspeed, reports honest-to-goodness groundspeed, independent of any > route, independent of the relationship between the ground track and > this-or-that navaid. > > > > , so it is only > > > accurate if you are flying directly toward that point... But a /velocities/groundspeed could be > > > used as a starting point ... > > It takes only a couple of lines of nasal to calculate the groundspeed > in terms of the already-available properties. Hint: > Aircraft/A-10/Nasal/aar.nas line 261 > ... so I don't understand what the discussion is about. Well I wasnt trying to start a war here ,simply trying to get my Primus 1000 system updated, but groundspeed is calculated in the source code , and since its been requested before , I thought it might be a good idea to show it in the property tree... I just dont see a reason for redoing everything in nasal that's already done in the source code > The Subject: line refers to groundspeed. If you want to ask about > something else, perhaps about ETE or ETA at this-or-that station, > then the answer might become route-dependent. (Different questions > have different answers!) > > > So: If there's a problem here that needs solving, please describe > the problem more fully. Like I said , it wasn't really a problem, it was a suggestion.... The only problem I see is the ai radar x-shift and y-shift that should REALLY be normalized to the radar range :) Have a nice day ... Cheers, Syd > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Flightgear-devel mailing list > Flightgear-devel@... > https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- syd & sandy ```