https://www.researchgate.net/post/How_to_convert_the_DN_values_to_reflectance2

http://planet.botany.uwc.ac.za/NISL/BDC332/Terrset/TerrSet%20Manual.pdf

Thanks a lot Morteza Safari & Firoz Ahmad.

 dear Mr. SafarI,

With your explanation and other studies, I've concluded that by doing atmospheric correction the DN values, have become reflectance values. is it right?

My Dear colleague,

Although I have not much information in your topic, but the following links and RG-discussions can direct you to address the issue:

http://yceo.yale.edu/how-convert-landsat-dns-top-atmosphere-toa-reflectance

https://www.researchgate.net/post/How_do_I_convert_DN_values_to_reflectance_values_for_landsat_7_and_8_images_one_using_ENVI

https://www.researchgate.net/post/The_first_Landsat_8_image_is_available_How_can_the_DN_value_of_the_image_be_converted_to_at-sensor_reflectance

https://landsat.usgs.gov/using-usgs-landsat-8-product

http://community.hexagongeospatial.com/t5/Spatial-Recipes/Landsat-8-Top-of-Atmosphere-Reflectance-Conversion/ta-p/4223

And here is a YouTube Tutorial 

https://www.youtube.com/watch?v=MM_I3NZibYE

Thank you, Professor,

 my question was answered and the problem was solved.

Ragards

many, (all?) L8 and earlier scenes are now being reissued as Surface Reflectance 'products' . Consider obtaining another copy of your imagery and you may find that work has been done for you (or you could compare your results to the Surface Reflance products generated by the USGS.....

Phil Crossley Sir send me link of Surface Reflance products generated by the USGS.....

Arvind. When you're ready to search for Landsat Images (either by lat./long coordinates or by Path/Row #), the Earth Explorer site ( https://earthexplorer.usgs.gov/ )makes it very easy. Part of that search process is to specify which datasets you want to search. The Surface Reflectance images are referred to as "Level 2" products (see the attached image). Any images you order and download from those results will have an _sr indication in the file name

Dear Phil Crossley

I have downloaded the level 2 of landsat 8 ( I got a link by mail )

As I did understand from your explanation ,it s already surface reflectance so I don 't have to correct it again using the MTL file?

I have tried to apply the DOS correction to the already corrected image to compare:Here is the result for band 2

• Band 2 ( provided by usgs level 2):pixel value between 158 and 1422
• Band 2 (after application of DOS correction and MTL file: Pixel value between 0.01 and 0.04

I got confused with this values.The aim of my work is to perform a land use classification.

Thanks

I'm sorry, I can't comment on whether to also use the DOS correction in addition to using the surface reflectance product from Landsat, or about the values you obtained from your application of the DOS method. My understanding is that all of the atmospheric correction methods built in to other software, such as the DOS method, were developed before the surface reflectance products were developed by the USGS; therefore, you should use whichever method you believe is best. I have decided to rely on the USGS since I regard their scientists as better qualified than I am to analyze these data. My advise would be to use the Landsat data and get to work on your LULC classification methods (which are inherently problematic anyway, and likely introduce far more error into your analysis (which you will have to check for anyway) than any minor discrepancy btw the the DOS method and the USGS algorithm....)

Dear All,

I am pleased to share my new method “A Simplified and Robust Surface Reflectance Estimation Method (SREM) for Use over Diverse Land Surfaces Using Multi-Sensor Data” published in MDPI #Remote Sensing Journal.

Abstract: https://www.mdpi.com/2072-4292/11/11/1344

PDF Version: https://www.mdpi.com/2072-4292/11/11/1344/pdf

https://www.researchgate.net/project/Simplified-and-Robust-Surface-Reflectance-Estimation-Method-SREM