The Impact of Choice of Solar Spectral Irradiance Model on Atmospheric Correction of Landsat 8 OLI Satellite Data

Fuqin Li,David L B Jupp,Stephen Sagar,Thomas Schroeder

doi:10.1109/tgrs.2020.3011006

Abstract

Many atmospheric correction schemes of radiance-based optical satellite data require the selection of normalized solar spectral irradiance models at the top of atmosphere (TOA). However, there is no scientific consensus in literature as to which available model is most suitable. This article examines five commonly used models applied to Landsat 8 Operational Land Imager (OLI) TOA radiance and reflectance products to assess the accuracy and stability between models used to derive surface reflectance products. It is assumed that the calibration of the United States Geological Survey (USGS) Landsat 8 OLI TOA reflectance and radiance products are accurate to currently claimed levels. The results show that the retrieved surface reflectance can exhibit significant variations when different solar irradiance models are used, especially in the OLI coastal blue band at 443 nm. From the five solar irradiance models, the Kurucz 2005 model showed the least bias compared with OLI TOA reflectance product and least variance in surface reflectance. Furthermore, improvement was obtained by adjusting the total solar irradiance (TSI) normalization, and additional validation was provided using observed in situ water leaving reflectance data. The results from this article are particularly relevant to aquatic applications and to satellite sensors that provide TOA radiance such as previous Landsat and other current and historical missions.

Highlights

AND BACKGROUNDT HE normalized solar spectral irradiance at the top of atmosphere (TOA) is an important boundary condition used in radiative transfer modeling as well as energy balances of the atmosphere [1]
The ratio, which estimates rt, is temporally stable and showed no variations based on land cover changes but only varies between different bands/wavelengths and selections of spectral solar constant model
When physics-based atmospheric corrections are applied to Landsat 8 Operational Land Imager (OLI) optical TOA radiance data using different spectral solar constant models, the resulting surface reflectance values can vary significantly

Summary

Introduction

T HE normalized solar spectral irradiance at the top of atmosphere (TOA) is an important boundary condition used in radiative transfer modeling as well as energy balances of the atmosphere [1]. It is a fundamental observation used in a wide range of applications ranging from climate modeling [2] to atmospheric correction of satellite data, where the sensors measure upwelling radiance resulting from. The total integrated energy over all wavelengths varies periodically with the Sun–Earth distance, and its value normalized to the mean Sun–Earth distance is called the solar constant. The structure and form of the spectral solar constant have been the focus of intensive and long-term studies incorporating ground and satellite observations, leading to the existence of a number of published estimates covering a wide range of wavelengths relevant to Earth observation at very high spectral resolutions [3]–[5], [7]

Results

Discussion

Conclusion