What is the meaning of spectral radiance?
Spectral radiance is the radiance of a surface per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. These are directional quantities.
What is spectral radiance in remote sensing?
Spectral reflectance is assumed to be different with respect to the type of land cover. This is the principle that in many cases allows the identification of land covers with remote sensing by observing the spectral reflectance (or spectral radiance) from a distance far removed from the surface.
How do you find the spectral radiance?
As shown in Figure 1, the radiance (R) of the source emitting area (A) equals the radiation power (P), which is emitted from A and propagates in solid angle Ω, divided by the area A and the solid angle Ω: R = P / (A x Ω).
What is photon radiance?
• Photon radiance L. q. • The photon flux emitted or absorbed by a surface, per unit solid angle, per unit projected. area.
What is the spectral intensity?
In radiometry, radiant intensity is the radiant flux emitted, reflected, transmitted or received, per unit solid angle, and spectral intensity is the radiant intensity per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength.
What is radiance vs irradiance?
Vaguely speaking, irradiance is the amount of light incoming to a certain point from possibly all directions, while radiance is the amount of light incoming to a point from a single direction.
What is a spectral signature in remote sensing?
spectral signature of the object in remote sensing. This can be defined as a unique pattern of. wavelengths radiated by an object. These can be categorised as. a) Spectral Variation: Variation in reflectivity and emissivity as a function of wavelength.
What is the difference between radiance and reflectivity?
Reflectance (or more specifically hemispherical reflectance) is a property of the material being observed. Radiance, on the other hand, depends on the illumination (both its intensity and direction), the orientation and position of the target and the path of the light through the atmophere.
What is difference between irradiance and radiance?
What is the difference between radiance and luminance?
The unit of radiance is W/sr-m2. In case of photometric quantity, the radiance is called as Luminance. We can use the conversion equation to obtain luminance from radiance. Where, Km is the constant which is called maximum spectral luminous efficacy and its value is 683 lm/W.
What are spectral quantities?
Definition: quantities in radiometry and photometry which describe the distribution e.g. of a radiant flux over different optical frequencies or wavelengths.
What is radiance factor?
radiance factor. β e; β quotient of the radiance of a surface element in a specified direction, L e,n and the radiance of the perfect reflecting diffuser or perfect transmitting diffuser identically irradiated and viewed, L e,d.