Proceedings of the Symposium on Global and Environmental Monitoring: Proceedings of the Symposium on Global and Environmental Monitoring

94 
TRANSMITTED IR 
LASER PULSE 
(IR beam scanned ±15“, 
its reflection from sea 
surface permits 
accurate determination 
of aircraft height.) 
TRANSMITTED BLUE-GREEN 
LASER PULSE 
(Blue-green beam scanned ±15“, its 
reflections from the surface and 
bottom of the sea permit estimation 
of sea depth.) 
DEPTH 
Figure 1: LARSEN 500 Laser Beam Geometry. 
sea depth = (1/2) T-delay * (c/r) 
c : speed of laser light in air 
r : refractive index of seawater 
T-delay : time separation between the surface and 
bottom returns 
Figure 2: Received Waveform. 
Figure 3: Waveform Corrupted by Noise. Figure 4: Shape of i/ca/g(<) as a Function of Parameter 
Sr.