Unit: sr-1

Resolution: 30m,16days(Scene cloud less than 10%)

Duration: 1989 - Present

Source: U.S. Geological Survey

Dataset Name: USGS_Landsat_OLI_DaTong

Product Name: USGS_Landsat_OLI_yyyy-MM-ddTOyyyy-MM-dd_L3A_DaTong_30M_RRS_Path/Row

( in which,  please reference to Landsat Worldwide Reference System-2(WRS-2) for information of Path/Row)

Product：Landsat8 Remote sensing reflectance 443nm, 482nm, 562nm,655nm, 865nm, 1610nm, 2200nm

                 Landsat4,5 Remote sensing reflectance 483nm, 560nm, 662nm, 835nm, 1648nm, 2206nm

                 Landsat7 Remote sensing reflectance 483nm, 560nm, 662nm, 835nm, 1648nm, 2206nm

Processing:

The data set was subjected to Radiometric Calibration and FLAASH atmospheric correction using ENVI software. First, the digital quantized value (DN) of the original image of the Landsat satellite is converted into a physical quantity such as a radiance value or a reflectance by Radiometric Calibration. Then, FLAASH atmospheric correction can estimate the properties of the atmosphere through the image header file (including sensor basic information such as wavelength and spectral bandwidth), spectral response function, and satellite image spectral information. In terms of aerosol model selection, FLAASH's alternative aerosol models include urban aerosols, rural aerosols, marine aerosols, aerosol-free and tropospheric aerosol models, which can be selected based on the specific satellite image coverage area.  The data output after FLAASH atmospheric correction is the apparent reflectivity ρw, which needs further calculation to obtain the remote sensing reflectivity Rrs. The calculation formula is as follows:

Where τ0 is the diffuse transmittance of the sun, τr is the Rayleigh optical thickness, and θo is the solar zenith angle.

For detail information，Please visit ENVI Helphttp://enviidl.com/help/#../Subsystems/envi/Content/PreprocessImagery/QUAC_FLAASH/FLAASH.htm?Highlight=FLAASH

Acknowledgment

Landsat Download link：http://earthexplorer.usgs.gov/

All the contents of this page are quoted from U.S. Geological Survey. All project

documentation and related publications can be found at the website: https://www.usgs.gov/land-resources/nli/landsat