implemented function

applications/SoundFieldSimulation/CombinedAtmosphereUrban/ita_cau_virtual_sound_source.m

 function [ virtual_source_pos ] = ita_cau_virtual_sound_source( receiver_pos, incident_direction, distance_or_attenuation, modus )
 %%ita_cau_virtual_sound_source Calculates a virtual sound source from an
-%incident direction and distance or spreading loss attenuation.
+%incident direction and the distance or spreading loss attenuation.
+
+if strcmp(modus,'spreading loss')
+
+%     distance = 10^(distance_or_attenuation/20);
+    distance = 1/distance_or_attenuation; %attenuation equals 1/r
+    
+else
+    
+    distance = distance_or_attenuation;
+       
+end
+
+virtual_source_pos = receiver_pos-incident_direction*distance/norm(incident_direction);
 
 end