De Jong Et Al 2002. Flashcards
What is a laser?
A laser is the electromagnetic signal in the frequency band of the optical window of the electromagnetic spectrum.
What does the propagation of light depend on in seawater?
Temp pressure and salinity.
What is transparency a function of?
A function of the amount of material suspended in water.
When no suspended material is present, what is attenuation expressed as?
As a function of absorption and scattering, with the absorption quantified by the ABSORPTION COEFFICIENT k.
When suspended material is present what is the absorption coefficient replaced by?
The extinction coefficient
Due to absorption or extinction, the intensity of radiation will…..
Due to absorption or extinction, the intensity of radiation will decrease with the increasing path of the laser Ray
What is the change in radiation intensity proportional to?
Intensity and thickness (expressed as the first order linear differential equation)
What does dissolved material in the water cause?
Increased absorption. Suspended matter increases scattering. Scattering increases with decreasing wavelength.
What is the extinction coefficient?
The fraction of light lost to scattering and absorption per unit distance travelled.
How is the extinction coefficient k characterised ?
No significant variation in T, S and P.
Nearly the same for filtered seawater and pure fresh water.
It is a function of Wavelength (graph)
What is the extinction coefficient?
The fraction of light lost to scattering and absorption per unit distance travelled.
How is the extinction coefficient k characterised ?
No significant variation in T, S and P.
Nearly the same for filtered seawater and pure fresh water.
It is a function of Wavelength (graph)
