considered valid for a short time, and accurate enough to perform the
automatic landing safely.
4. If the plane flies too high above the point L1 and cannot get a laser
altitude reading (usually it should be less than 25 meters to obtain an
valid laser altitude, the scanning distance will increase in a dark
environment), the plane will circle around L4 again, and then perform
the next runway scanning at a 5 meters lower then previous altitude. If
the very first scan is a success, no more scans will be performed, and the
plane will proceed with the normal landing procedure.
5 meters altitude reduction between 2 consecutive scans is a constant
value, and cannot be edited by user. If your runway scan altitude is set
