You wouldn't want to spend 20 minutes homing in on a beacon, only to find out that it is a heliport. To review, lighted land airports have alternating white and green beacons. Military airport beacons have two quick white flashes, followed by green. Heliports have green, yellow, and white beacons that pulse faster than beacons used for airports. A lighted water airport has a white and yellow beacon.
Many uncontrolled airports have pilot-controlled lighting.
High intensity is intended for daytime use when fog or obscuring precipitation is present, while low intensity is meant to be used at night. Visual glideslope indicators come in several varieties. The best known is the VASI, or visual approach slope indicator. A VASI can have either two or three rows of lights, called bars. The red bar will appear above a white bar.