Landsat-8
DN to Reflectance
Reflective band DN’s are converted to TOA reflectance using the rescaling coefficients in the MTL file:
where:
\(R(b)'\) is the Top of Atmosphere planetary reflectance, without correction for solar angle.
Note that \(R(b)'\) does not contain a correction for the sun angle.
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\(M_b\) is the band-specific multiplicative rescaling factor from the metadata (REFLECTANCE_MULT_BAND_x, where x is the band number)
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\(A_b\) is the band-specific additive rescaling factor from the metadata (REFLECTANCE_ADD_BAND_x, where x is the band number)
Top of Atmosphere reflectance with a correction for the sun angle is then:
where:
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\(R(b)\) is the TOA planetary reflectance
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\(θ_{SE}\) is the local sun elevation angle. The scene center sun elevation angle in degrees is provided in the metadata (SUN_ELEVATION).
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\(θ_{SZ}\) is the local solar zenith angle; \(θ_{SZ} = 90° - θ_{SE}\)
Input
The input is an ingested Landsat-8, see details here.
Output
The output is a STAC item geojson ... including the assets ...