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TOA correctionthe reflectance range was like for example 0.0023 to -1.02356 for some band and -0.0156 to 0.009. Why is this reflectance range slightly out of range? Isn't it should be in exactly in between 0 to 1. If so what can we do to correct this? this is the image showing how i did TOA correction and the result of it

  • I suspect that you may well have made an error in your correction - can you specify exactly how you did your correction? – Mikkel Lydholm Rasmussen Jun 5 '16 at 12:16
  • 1)First i set projection to WGS84 2)then i added all bands of landsat 8 image of my study area 3)then i started applying TOA correction following the lansat 8 guide from raster calculator 4)the formula i used is as:ρλ' = MρQcal + Aρ 5)After that it was divided by Sin(solar elevation) – KGISdummy Jun 8 '16 at 10:49
  • 6)And i did this correction for every bands except panchromatic abd TIRS bands. 7) the resulting raster was supposed to be in the range 0-1 exactly but in my case it didn't happen. 8) then i had to apply streching(i used DRA option), then only the range adjusted to somewhat near the 0-1 range but still not perfectly. – KGISdummy Jun 8 '16 at 10:54
  • @MikkelLydholmRasmussen i have attached the snapshot of my work. So, can you please correct my work and what iam missing here – KGISdummy Jun 8 '16 at 11:15
  • you are multiplying by something other than the gain. The gain is usually 0.00002 and not 0.00005. – Mikkel Lydholm Rasmussen Jun 8 '16 at 17:46
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I have been using the the Semi automatic classification plugin of QGIS and I haven't had that problem. The plugin has a module for TOA correction.See the documentation

  • ok i'll try this option – KGISdummy Jun 8 '16 at 10:55

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