What is water-leaving radiance?
Water-leaving radiance (Lw), which is defined as the upwelling radiance from the sea to the air is a fundamental parameter for ocean-color remote sensing, since its spectrum provides infor- mations on the sea-surface layer, such as chlorophylla concentration [1].
How atmospheric correction is done?
Atmospheric correction of the radiative transfer method involves simulating the relationship between the atmospheric parameters of the satellite synchronization and the true reflectivity of the surface by simulating the radiation transmission process between the atmospheric–surface remote sensor.
What is atmospheric path radiance?
Path radiance is the radiance detected by a spaceborne sensor above a nonreflective surface and is the result of backscattering to space by particles and molecules in the atmosphere. In specific measurement conditions the path radiance can be measured also from the ground.
What is water leaving reflectance?
Reflectance does not propagate through space and it cannot leave a surface, so it does not make sense to speak of the “water-leaving reflectance.” However, the term “water-leaving reflectance” is well established shorthand for “reflectance based on the water-leaving radiance and the incident irradiance,” and we will use …
Why do we need atmospheric correction?
The objective of atmospheric correction is to determine true surface reflectance values by removing atmospheric effects from satellite images. Atmospheric correction is arguably the most important part of the pre-processing of satellite remotely sensed data and any omission produces erroneous results.
Is atmospheric correction necessary?
In general, atmospheric correction is unnecessary prior to unsupervised image classification or change detection. Chinsu et al. (2015) suggest that atmospheric correction will not improve the accuracy of results in land use and land cover (LULC) classification.
How does path radiance affect remote sensing?
This path radiance generally introduces unwanted radiometric noise in the remotely sensed data and complicates the image interpretation process.
What is RRS in 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.
Which atmospheric correction method is most useful for easy detection of haze from the images and why?
Answer: Spatial “information based correction”: “spatial matching of clear and hazy regions of an image” is method used for detection of haze from the images.
Why do we do atmospheric correction?
Does Sentinel 2 Level 2A images require atmospheric correction?
The Level-2A processing includes a scene classification and an atmospheric correction applied to Top-Of-Atmosphere (TOA) Level-1C orthoimage products.
Why is atmospheric correction necessary?
Atmospheric correction of optical imagery typically means removing the effects of clouds and aerosols from a radiance image. The result is an apparent surface reflectance image, which can be used to extract accurate spectral information from features on the Earth’s surface.
What is water-leaving reflectance?
What is sensor radiance?
The at-sensor radiance of a pixel in a longwave infrared (LWIR) image represents the surface temperature, the surface emissivity, which is similar during the day and at night, and the atmospheric contribution, which is expressed differently during the day and at night.
What is atmospheric correction?
Atmospheric correction is a process in which the top-of-atmosphere radiance received by sensors is converted to surface reflectance.
Are atmospheric correction models suitable for inland waters?
Atmospheric correction models originally developed for ocean color remote sensing are based on several implicit assumptions about the atmosphere and the target environment that are often not applicable for inland waters.
How does atmospheric correction affect the image quality?
The figure shows that atmospheric correction better removes the atmospheric effects, especially atmospheric aerosol scattering, and improves the clarity of the image. Figure 4.9. GF-1 WFV data true color composite map (left: before atmospheric correction; right: after atmospheric correction).
Does atmospheric correction improve the clarity of GF-1 images?
The figure shows that atmospheric correction better removes the atmospheric effects, especially atmospheric aerosol scattering, and improves the clarity of the image. Figure 4.9. GF-1 WFV data true color composite map (left: before atmospheric correction; right: after atmospheric correction). Shard Chander,