2

I am trying to figure out Landsat 8 data corrections and calibrations. Actually, I don't really know how this can be done and which data needs what kind of correction and calibration for further processing. Basically new for these processing. So, I prefer to download already corrected and calibrated Landsat scenes.

I have downloaded Landsat 8 OLI/TIRS C1 Level-1 data from https://glovis.usgs.gov/. It seems that there is no correction and calibration. I got following data in the package.

LC08_L1TP_129026_20140712_20170421 = *

        *_01_T1_b1 to b11
        *_01_T1_bqa
        *_01_T1_MTL
        *_01_T1_ANG

Also I downloaded same scene from https://espa.cr.usgs.gov/. It supposed to be corrected and calibrated. I guess it is. Because the value range of band data are different. Following are the additional data plus the above package, cause I ticked TOA calibrated, and SR, ST and angle corrected.

*_01_T1_sr_band1 to band7
*_01_T1_toa_band1 to band9
*_01_T1_pixel_qa
*_01_T1_radsat_qa
*_01_T1_sr_aerosol
*_01_T1_sensor_azimuth_band4
*_01_T1_sensor_zenith_band4
*_01_T1_solar_azimuth_band4
*_01_T1_solar_zenith_band4

Are the data downloaded from https://espa.cr.usgs.gov/ corrected and calibrated to be used for further analysis directly?

I am wondering, if the band data already corrected and calibrated, what are the additional data for (i.e. sr_band1-band7, _01_T1_toa_band1-band9, _01_T1_sensor_azimuth_band4 and _01_T1_sensor_zenith_band4)?

2

Yes, these are the Level 2 data products, which are calibrated to surface reflectance. These are able to be used for further analysis directly.

  • *_01_T1_sr_band1 to band7 refers to the surface reflectance (bottom of atmosphere) products
  • *_01_T1_toa_band1 to band9 refers to the top of atmosphere products

The remaining bands are quality assessment bands--as described by the USGS:

Landsat Surface Reflectance products include Quality Assessment (QA) bands to identify the pixels that exhibit adverse instrument, atmospheric, or surficial conditions. Used effectively, QA information improves the integrity of science investigations by indicating which pixels might be affected by instrument artifacts or subject to cloud contamination.

And further described in great detail here:

https://landsat.usgs.gov/landsat-surface-reflectance-quality-assessment

  • So, *_01_T1_sr_band1 to band7 are corrected to surface reflectance and *_01_T1_toa_band1 to band9 are bands corrected to top of atmosphere of the uncorrected bands data (Level 1), respectively, right? What about If I wanted corrected band data to both of them and others (sensor_zenith, solar_azimuth) in single layer? – Vandka Dec 7 '17 at 4:16
  • Yes, for the first question. I'm unclear what you are looking for in the second question--could you please elaborate? – Aaron Dec 7 '17 at 13:22
0

level 1 product does not have atmospheric correction https://landsat.usgs.gov/does-landsat-level-1-data-processing-include-atmospheric-correction you need to download level 2 product for atmospheric correction. I use earth explorer to download landsat data https://earthexplorer.usgs.gov/ choose your level from options in datasets. here is more information with Level 1 data https://landsat.usgs.gov/landsat-processing-details about geometric corrections and radiometric calibration. I hope it helps. Good luck!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.