What is radiance in image processing?
Radiance is the amount of radiation coming from an area. To derive a radiance image from an uncalibrated image, a gain and offset must be applied to the pixel values. Radiance includes radiation reflected from the surface,bounced in from neighboring pixels, and reflected from clouds above the area of the pixel.
What does the remote sensor record radiance or reflectance?
Sensors measure the radiance, which corresponds to the brightness in a given direction toward the sensor; it useful to define also the reflectance as the ratio of reflected versus total power energy.
What is the difference between irradiance and radiance?
In context|physics|lang=en terms the difference between radiance and irradiance. is that radiance is (physics) the flux of radiation emitted per unit solid angle in a given direction by a unit area of a source while irradiance is (physics) the radiant power received by unit area of surface.
What is sensor radiance?
The at-sensor radiance, Ls, at any wavelength, λ, can be expressed as[4]Ls=1πEρ+MTτθ+Luwhere E is the irradiance at the surface of the Earth, ρ is the reflectance of the Earth’s surface, MT is the spectral radiant exitance of the surface at temperature, T, τθ is the transmissivity of the atmosphere at zenith angle θ.
What is reflectance remote sensing?
Definition. Remote Sensing Reflectance, Rrs(λ; sr-1), is water-leaving radiance, Lw(λ), corrected for bidirectional effects of the air-sea interface and sub-surface light field, and normalized by downwelling solar irradiance, Ed(λ), just above the sea surface.
What is the difference between radiance and luminance?
The radiant flux emitted from a point source in a certain direction per unit solid angle per unit projected area perpendicular to the specified direction is called radiance. In case of photometric quantity, the radiance is called as Luminance. …
What is surface reflectance?
Surface reflectance is the amount of light reflected by the surface of the Earth. It is a ratio of surface radiance to surface irradiance, and as such is unitless, with values between 0 and 1.