What is the reflectance curve?
What is the reflectance curve?
A curve that illustrates the reflectance of light from a surface, such as paper, wavelength-by-wavelength throughout the visible spectrum, as a means of determining the color of that surface.
What is the reflectance of water?
5 to 70%
Reflectance of water ranges from 5 to 70%. Reflectance is low at lower incidence angle and increases for higher incidence angles. The energy that is reflected by features on the earth’s surface over a variety of different wavelengths will give their spectral responses in the remote sensing systems.
Does water have a high reflectance?
In its liquid state, water has relatively low reflectance, with clear water having the greatest reflectance in the blue portion of the visible part of the spectrum. Water has high absorption and virtually no reflectance in near infrared wavelengths range and beyond.
What is reflectance factor?
[7.3. 3.18] The ratio of the flux actually reflected by a sample surface to that which would be reflected into the same reflected-beam geometry by an ideal (glossless), perfectly diffuse (Lambertian), completely reflecting standard surface irradiated in exactly the same way as the sample.
What is spectral reflectance curve of vegetation?
The spectral reflectance curve of healthy green vegetation has a significant minimum of reflectance in the visible portion of the electromagnetic spectrum resulting from the pigments in plant leaves. Reflectance increases dramatically in the near infrared.
Why are there differences between the clear water and turbid water reflectance?
The turbid water reflectance spectrum exhibits higher values than clear water in the near-infrared region and approaches zero at longer wavelengths [44] . This is due to the concentration of solutes, sediments and organic matter, whose presence reinforces the reflection in the near-infrared band. …
Why is the spectral signature of water low?
As water has almost no reflection in the near infrared range it is very distinct from other surfaces. Water surfaces will therefore be clearly delimited as dark areas (low pixel values) in images recorded in the near infrared range. The spectral signature for green plants is very characteristic.
What is the reflectance of glass?
Light Reflection and Transmission in Glass. The light passing through glass is not only reflected on the front surface, but also on the back. In fact, the light may be reflected back and forth several times. Therefore, the total reflectance through a glass window is 2·R / (1+R).
What can derivative reflectance spectra tell us about seawater absorption in the Caribbean?
Derivative reflectance spectra revealed concealed peaks of both reflectance and absorption curves of Caribbean seawater and elements contained within it.
How do you calculate surface reflectance at sea surface?
Sea surface reflectance R(λ) is operationally defined as the ratio between upwelling irradiance Eu(λ,0) and the downwelling irradiance Ed(λ,0) at wavelength λ at the surface (depth Z = 0) and is expressed as:(1)Rλ,0=Euλ,0Edλ,0
Where is the reflectance of water normally observed in the spectrum?
The reflectance of water is normally observed within the visible spectrum as incident radiation is completely absorbed within the NIR region and beyond, the reflection of water is typically determined by components found within the water, suspended on the surface and the ones at the bottom,…
How does reflectance affect Ocean Colour?
Changes of ocean colour are determined by the spectral variations of the reflectance R (λ, 0). The operational expression of Equation (1) can be related to physical properties of water.