Glideslope

Fresnel Lens Optical Landing System (FLOLS)

Carrier Qualification

GLIDESLOPE

Because of the divergence of each lens cell, the size of the ball projected by that cell increases as dis-

tance from that cell increases, and vice versa. The following graphic illustrates this relationship, as well as

the sink rate/ball position relationship. Note that at 1 mile the thickness of the center cell is approximately

36 ft. The entire lens is 180 ft thick at one mile and only 15 ft thick at the ramp. It must be noted also that

as distance increases, resolution of the cells decreases. Thus, the information you receive within one mile

is better resolved and more accurate the closer the aircraft gets.

FPM

0

~90

FPM

~800

M

36.2' ~700 FP

27.1'

M

~600 FP

18.1'

9'

~500 FPM

2.2'

RAMP

1/4 mile

1/2 mile

3/4 mile

1 mile

1 1/4 mile

1 1/2 mile

Lens Thickness

14.9'

45.2'

90.4'

135.6'

180.8'

Figure 5: OPTIMUM GLIDESLOPE

(7-01) Change 2

Page 5