I downloaded calibrated/corrected Landsat 8 data (Level 2) from ESPA (https://espa.cr.usgs.gov/) to do land cover classification. But there are many corrections and calibrations can be done as listed below and maybe more, such as:
- Surface Reflectance - Top of Atmospheric - sensor zenith and azimuth - solar zenith and azimuth - geometric - radiometric
I am not sure all of them were processed on the scene. What are the must do corrections/calibrations for Land cover classification analysis?