On Tue, 29 May 2007 21:36:55 -0400 John Denker <[EMAIL PROTECTED]> 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@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- syd & sandy <[EMAIL PROTECTED]> ------------------------------------------------------------------------- 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@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
