On February 20, 2008 05:36:16 pm Mike Schuh wrote: > On Wed, 20 Feb 2008, Melchior FRANZ wrote: > >* Melchior FRANZ -- Wednesday 20 February 2008: > >> One effect that could also be considered is wind speed. > > > >Hmm ... and temperature. Very hot should probably reduce > >the visibility as well, even if it's dry. Have to play > >a bit more with temp/visibility, wind/visibility etc. > >tables. > > I wonder if a multiple regression against several factors would turn up > anything useful: > > vis = f(humidity,temp,wind,ceiling,elevation,sun_angle,ground_cover) > > Not sure how to incorporate sun_angle for values < 0 (i.e., night). Moon? > > ground_cover might allow for dusty areas v. urban settings, etc. > > This line of investigation sounds very interesting! > > -- > Mike Schuh - Seattle, Washington USA > http://www.farmdale.com
You are forgetting the term that matters the most -- density of the particulate matters. By particulate matters, it could also be air molecules themselves. Sun angle by itself wouldn't be useful. You will also need to know the types of particles you are dealing with and their scattering functions. You will then use the scattering functions to determine how much light is being directed toward or away from you. Ground cover is definately a variable, and an example you have pointed out is urban setting. The other settings would be desert, forest, ocean and snow. Ampere ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
