Skip to main content
Geographic Information Systems

Return to Answer

Changed Links 1 and 2 (Chander et al and SPOT ESUN) to archive links, as the original links have died.
Source Link
edit approved Sep 14, 2022 at 17:28
Needs_Caffeine
edit approved Sep 14, 2022 at 17:28
Needs_Caffeine
  • 153
  • 1
  • 10

There is two ways you can do this:

  1. Inside the toolbox:
  • Grass: i.atcorr: performs atmospheric correction (i don´t know if it works with spot)
  • Orfeo Toolbox: Optical calibration (works with spot 5)
  1. Inside toolbox --> band math

  • you can read the metadata, look for the coeficients for the following equations ( for example: <SUN_ELEVATION>, <PHYSICAL_BIAS>, <PHYSICAL_GAIN>)

  • you can find d in chander et al. 2009Chander et al. 2009

  • you can find ESUN in SPOT ESUNSPOT ESUN

  • transform DN to TOA radiance (L=DN/Ak; A= bandgain, B=bandbias)

  • transform TOA radiance to TOA reflectance (p=[PI*d^2*L]/[ESUN*cos(theta)]; PI=3,14..., d= distance to solar to earth, L = TOA radiance, ESUN = Mean exoatmospheric solar irradiance, theta = Solar zenith angle (90-SUN_ELEVATION))

  • you must do this for every band

There is two ways you can do this:

  1. Inside the toolbox:
  • Grass: i.atcorr: performs atmospheric correction (i don´t know if it works with spot)
  • Orfeo Toolbox: Optical calibration (works with spot 5)
  1. Inside toolbox --> band math

  • you can read the metadata, look for the coeficients for the following equations ( for example: <SUN_ELEVATION>, <PHYSICAL_BIAS>, <PHYSICAL_GAIN>)

  • you can find d in chander et al. 2009

  • you can find ESUN in SPOT ESUN

  • transform DN to TOA radiance (L=DN/Ak; A= bandgain, B=bandbias)

  • transform TOA radiance to TOA reflectance (p=[PI*d^2*L]/[ESUN*cos(theta)]; PI=3,14..., d= distance to solar to earth, L = TOA radiance, ESUN = Mean exoatmospheric solar irradiance, theta = Solar zenith angle (90-SUN_ELEVATION))

  • you must do this for every band

There is two ways you can do this:

  1. Inside the toolbox:
  • Grass: i.atcorr: performs atmospheric correction (i don´t know if it works with spot)
  • Orfeo Toolbox: Optical calibration (works with spot 5)
  1. Inside toolbox --> band math

  • you can read the metadata, look for the coeficients for the following equations ( for example: <SUN_ELEVATION>, <PHYSICAL_BIAS>, <PHYSICAL_GAIN>)

  • you can find d in Chander et al. 2009

  • you can find ESUN in SPOT ESUN

  • transform DN to TOA radiance (L=DN/Ak; A= bandgain, B=bandbias)

  • transform TOA radiance to TOA reflectance (p=[PI*d^2*L]/[ESUN*cos(theta)]; PI=3,14..., d= distance to solar to earth, L = TOA radiance, ESUN = Mean exoatmospheric solar irradiance, theta = Solar zenith angle (90-SUN_ELEVATION))

  • you must do this for every band

Source Link
Pau
Pau
  • 576
  • 3
  • 13

There is two ways you can do this:

  1. Inside the toolbox:
  • Grass: i.atcorr: performs atmospheric correction (i don´t know if it works with spot)
  • Orfeo Toolbox: Optical calibration (works with spot 5)
  1. Inside toolbox --> band math

  • you can read the metadata, look for the coeficients for the following equations ( for example: <SUN_ELEVATION>, <PHYSICAL_BIAS>, <PHYSICAL_GAIN>)

  • you can find d in chander et al. 2009

  • you can find ESUN in SPOT ESUN

  • transform DN to TOA radiance (L=DN/Ak; A= bandgain, B=bandbias)

  • transform TOA radiance to TOA reflectance (p=[PI*d^2*L]/[ESUN*cos(theta)]; PI=3,14..., d= distance to solar to earth, L = TOA radiance, ESUN = Mean exoatmospheric solar irradiance, theta = Solar zenith angle (90-SUN_ELEVATION))

  • you must do this for every band