TPE, LightTrac , Sun Sur Lite and Sun Seeker and they are all right except one missing function:They dont allow me to see if there are obstacles such as a tall building or a hill which blocks the sun...fe: lets assume that I am searching for a fine restaurant within walking distance of my location to eat outdoors under the sun..It can be midday like 13:00 so that the sun is 90 degrees to us and at