[GRASS-dev] Re: [GRASS GIS] #63: r.los: patch to support earth curvature

[GRASS GIS]

#63: r.los: patch to support earth curvature
--------------------------+-------------------------------------------------
  Reporter:  neteler      |       Owner:  grass-dev at lists.osgeo.org
      Type:  enhancement  |      Status:  new                      
  Priority:  major        |   Milestone:  6.4.0                    
 Component:  default      |     Version:  svn-trunk                
Resolution:               |    Keywords:                           
--------------------------+-------------------------------------------------
Comment (by hamish):

 {{{
 r.los/main.c:
 @@ -109,9 +114,13 @@
      opt6->type = TYPE_DOUBLE;
      opt6->required = NO;
      opt6->answer = "10000";
 -    opt6->options = "0-999999";
 +    opt6->options = "0-9999999999";
      opt6->description = _("Maximum distance from the viewing point
 (meters)");
 }}}


 Why increase that so much?
 At the top of Everest, the maximum theoretical distance to the horizon
 would be about 3.86*sqrt(8850) = 350km = 350,000m.
   http://mintaka.sdsu.edu/GF/explain/atmos_refr/horizon.html

 make it 500000m?


 Should all the new  /* try to get the radius ... */ code live behind a
 check for the -c flag? in case the proj stuff has problems.



 Hamish

-- 
Ticket URL: <http://trac.osgeo.org/grass/ticket/63#comment:3>
GRASS GIS <http://grass.osgeo.org>
GRASS Geographic Information System (GRASS GIS) - http://grass.osgeo.org/