# Auslesen der Koordinaten
    my ($lat_old) = $line =~ m/lat='(-?\d+\.\d+)/;
    my ($lon_old) = $line =~ m/lon='(-?\d+\.\d+)/;
    if (defined ($lat_old) && defined ($lon_old)){

print "lon old:   ".$lon_old."\n";
print "lat old:   ".$lat_old."\n\n";
        
                 #konvertierung in Bogenmass
# hier werden einige Berechnungen ausgeführt   
 
print "lon new:   ".$lon_new."\n";
print "lat new:   ".$lat_new."\n";
print "-------------------------------------\n";

  print "davor line: ".$line."\n";
  print "lon new:   ".$lon_new."\n";
  print "lat new:   ".$lat_new."\n";
  
      $line =~ s/lon='(\d+\.\d+)/lon='$lon_new/;
      $line =~ s/lat='(\d+\.\d+)/lat='$lat_new/;
          
  print "danach line: ".$line."\n";