// calculate range to target in feet and nautical miles
double lat_range = fabs(pos.lat() - user_latitude) * ft_per_deg_lat;
double lon_range = fabs(pos.lon() - user_longitude) * ft_per_deg_lon;
- double range_ft = lat_range*lat_range + lon_range*lon_range;
+ double range_ft = sqrt(lat_range*lat_range + lon_range*lon_range);
range = range_ft / 6076.11549;
// Calculate speed of rising air if within range.