Analysis of directional effects on atmospheric correction

Abstract Atmospheric correction in the Visible and Near Infrared (VNIR) spectral range of remotely sensed data is significantly simplified if we assume a Lambertian target. However, natural surfaces are anisotropic. Therefore, this assumption will introduce an error in surface directional reflectance estimates and consequently in the estimation of vegetation indexes such as the Normalized Difference Vegetation Index (NDVI) and the surface albedo retrieval. In this paper we evaluate the influence of directional effects on the atmospheric correction and its impact in the NDVI and albedo estimation. First, we derived the NDVI and surface albedo from data corrected assuming a Lambertian surface, then by using the BRDF model parameters used in the albedo retrieval, we account for the coupling effect and retrieved an improved NDVI and albedo. The study used Climate Modeling Grid (CMG) MODIS data, which has a spatial resolution of 0.05°. We focused our analysis on four Aeronet sites located in the United States of America: KONZA EDC (a prairie region in the Flint Hills, Kansas), Howland (a forest area in Maine), Walker Branch (a forest area in Tennessee) and GSFC (at NASA's Goddard Space Flight Center). The results indicate that the relative errors due to the Lambertian assumption on the surface reflectance are 3–12% in the visible and 0.7–5.0% in the near-infrared, around 1% on the NDVI and less than 1% on the albedo.

[1]  Philip B. Russell,et al.  Aircraft measurements of spectral surface albedo and its consistency with ground‐based and space‐borne observations , 2008 .

[2]  Yujie Wang,et al.  Local analysis of MISR surface BRF and albedo over GSFC and mongu AERONET sites , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[3]  J. H. Apfel.  Phase retardance of periodic multilayer mirrors. , 1982, Applied optics.

[4]  Didier Tanré,et al.  Second Simulation of the Satellite Signal in the Solar Spectrum, 6S: an overview , 1997, IEEE Trans. Geosci. Remote. Sens..

[5]  Eric F. Vermote,et al.  Correction of MODIS surface reflectance time series for BRDF effects , 2012 .

[6]  P. Deschamps,et al.  Influence of the atmosphere on space measurements of directional properties. , 1983, Applied optics.

[7]  Eric Vermote,et al.  Atmospheric correction for the monitoring of land surfaces , 2008 .

[8]  John R. G. Townshend,et al.  The Global Climate Observing System (GCOS) , 1996 .

[9]  Alan H. Strahler,et al.  Consistency of MODIS surface bidirectional reflectance distribution function and albedo retrievals: 1. Algorithm performance , 2003 .

[10]  Christopher Justice,et al.  Towards a Generalized Approach for Correction of the BRDF Effect in MODIS Directional Reflectances , 2009, IEEE Transactions on Geoscience and Remote Sensing.

[11]  Yujie Wang,et al.  Atmospheric Correction at AERONET Locations: A New Science and Validation Data Set , 2009, IEEE Transactions on Geoscience and Remote Sensing.

[12]  A. Smirnov,et al.  AERONET-a federated instrument network and data archive for aerosol Characterization , 1998 .

[13]  Alexei Lyapustin,et al.  Atmospheric and geometrical effects on land surface albedo , 1999 .

[14]  S. Liang.  Narrowband to broadband conversions of land surface albedo I Algorithms , 2001 .

[15]  W. Lucht.  Expected retrieval accuracies of bidirectional reflectance and albedo from EOS-MODIS and MISR angular sampling , 1998 .

[16]  Alexei Lyapustin,et al.  Assessment of biases in MODIS surface reflectance due to Lambertian approximation , 2010 .

[17]  Yanmin Shuai,et al.  Validation of Moderate Resolution Imaging Spectroradiometer (MODIS) albedo retrieval algorithm: Dependence of albedo on solar zenith angle , 2009 .

[18]  Alan H. Strahler,et al.  Consistency of MODIS surface BRDF/Albedo retrievals 1. Algorithm performance , 2003 .

[19]  D. E. Harrison,et al.  Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC (2010 Update) , 2010 .

[20]  E. Vermote,et al.  Second Simulation Of The Satellite Signal In The Solar Spectrum - 6s Code , 1990, 10th Annual International Symposium on Geoscience and Remote Sensing.

[21]  Feng Gao,et al.  Use of Moderate-Resolution Imaging Spectroradiometer bidirectional reflectance distribution function products to enhance simulated surface albedos , 2004 .

[22]  F. Maignan,et al.  Bidirectional reflectance of Earth targets: evaluation of analytical models using a large set of spaceborne measurements with emphasis on the Hot Spot , 2004 .

[23]  Kriebel Kt,et al.  Measured spectral bidirectional reflection properties of four vegetated surfaces. , 1978 .

[24]  Alan H. Strahler,et al.  Geometric-optical bidirectional reflectance modeling of the discrete crown vegetation canopy: effect of crown shape and mutual shadowing , 1992, IEEE Trans. Geosci. Remote. Sens..

[25]  J. Roujean,et al.  A bidirectional reflectance model of the Earth's surface for the correction of remote sensing data , 1992 .

[26]  K. Kriebel,et al.  Measured spectral bidirectional reflection properties of four vegetated surfaces. , 1978, Applied optics.

[27]  Chad J. Shuey,et al.  Validating MODIS land surface reflectance and albedo products: methods and preliminary results , 2002 .

[28]  C. Justice,et al.  A framework for the validation of MODIS Land products , 2002 .

[29]  Y. Kaufman,et al.  Non-Lambertian Effects on Remote Sensing of Surface Reflectance and Vegetation Index , 1986, IEEE Transactions on Geoscience and Remote Sensing.

[30]  Alan H. Strahler,et al.  The interrelationship of atmospheric correction of reflectances and surface BRDF retrieval: a sensitivity study , 1999, IEEE Trans. Geosci. Remote. Sens..

[31]  Philip Lewis,et al.  On the information content of multiple view angle (MVA) images , 1997 .