Landsat8 DN to TOA Reflectance (minus values)

[المشرف العام]

I'm learning how to perform atmospheric correction manually, hence not using the automated methods available in ENVI

metadata (band 1) for my Landsat 8 scene is as follows;

RADIANCE_MULT_BAND_1 = 1.2344E-02

RADIANCE_ADD_BAND_1 = -61.72016

REFLECTANCE_MULT_BAND_1 = 2.0000E-05

REFLECTANCE_ADD_BAND_1 = -0.100000

SUN_ELEVATION = 48.12237303

So when I use band math to calculate TOA Radiance I type in this:

(0.012344*B1)-61.72016

And it yields a spectral statistics that look kind-of right

When I use any of the following band math formulae;

TOA Reflectance (excluding sun elevation adjustment)

(B1*0.00002)-0.1

TOA Reflectance (including sun elevation adjustment)

((B1*0.00002)-0.1)/0.74457226676389733207607359928648

Or calculate straight from the raw DN to TOA Reflectance (including sun elevation adjustment)

((((0.012344*B1)-61.72016)*0.00002)-0.1)/0.74457226676389733207607359928648

I end up with something like this:



which looks painfully incorrect.

I've googled and either my search terms are rubbish or basically noone uses manual band math to do this...

Any suggestions would be welcome.



أكثر...