What is the spectral reflectance of soil?

04/20/2020 Off By admin

What is the spectral reflectance of soil?

Spectral reflectance, under laboratory conditions, for all the soils increases with the wavelength from visible to infrared region except at 950 nm and 1200 nm, where reflectance decreases in all soils, which might be due to weaker water absorption bands and also at 1350 nm, which is strong water absorption band.

What is the spectral reflectance of vegetation?

At about 0.7 μm, the reflectance of healthy vegetation increases dramatically. In the range from about 0.7 to 1.3 μm, a plant leaf typically reflects, 40 to 50 per cent of the energy incident upon it. Plant reflectance in the range 0.7 to 1.3 μm results primarily from the internal structure of plant leaves.

How does soil moisture affect reflectance?

As moisture content of soils increased, reflectance from the soil sample decreased, which indicates that water is a strong light absorber than a sandy soil sample. Wet soil spectra was reconstructed by removing the moisture content effect and compared with the dry spectra of the same soil sample.

How does surface roughness affect soil reflectance?

Specifically, the higher the roughness is, the higher the reflectivity of the sample is. This phenomenon is more noticeable when the proportion of white endmember (PWE) is large, and as the white area ratio decreases, the reflectance difference gradually decreases.

How is spectral reflectance calculated?

Spectral reflectance is defined as (Equation [6.2]):[6.2]ρλ=PλP0λwhere Pλ is the spectral concentration of the radiant power reflected by the medium and P0λ is the spectral concentration of radiant power incident on the medium.

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.

What is the standard spectral reflectance curve for almost all healthy green vegetation?

Chlorophyll strongly absorbs light at wavelengths around 0.45 (blue) and 0.67 µm (red) and reflects strongly in green light, therefore our eyes perceive healthy vegetation as green. The high reflectance between 0.7 and 1.3 µm results primarily from the internal structure of plant leaves.

What are some of the factors that affect the reflective nature of water?

The factors that affect the variability in reflectance of a water body are depth of water, materials within water and surface roughness of water.

What is meant by spectral signature?

Spectral signature is the variation of reflectance or emittance of a material with respect to wavelengths (i.e., reflectance/emittance as a function of wavelength). The spectral signature of stars indicates the composition of the stellar atmosphere. Each substance will have its own unique pattern of spectral lines.