Next Article in Journal
Pansharpening Using Guided Filtering to Improve the Spatial Clarity of VHR Satellite Imagery
Next Article in Special Issue
Intercomparison of Surface Albedo Retrievals from MISR, MODIS, CGLS Using Tower and Upscaled Tower Measurements
Previous Article in Journal
R-CNN-Based Ship Detection from High Resolution Remote Sensing Imagery
Previous Article in Special Issue
Evaluating the Spatial Representativeness of the MODerate Resolution Image Spectroradiometer Albedo Product (MCD43) at AmeriFlux Sites
Open AccessEditor’s ChoiceArticle

A Method for Landsat and Sentinel 2 (HLS) BRDF Normalization

Department of Geographical Sciences, University of Maryland, College Park, MD 20742, USA
NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20740, USA
Author to whom correspondence should be addressed.
Remote Sens. 2019, 11(6), 632;
Received: 24 January 2019 / Revised: 7 March 2019 / Accepted: 11 March 2019 / Published: 15 March 2019
(This article belongs to the Special Issue Remotely Sensed Albedo)
The Harmonized Landsat/Sentinel-2 (HLS) project aims to generate a seamless surface reflectance product by combining observations from USGS/NASA Landsat-8 and ESA Sentinel-2 remote sensing satellites. These satellites’ sampling characteristics provide nearly constant observation geometry and low illumination variation through the scene. However, the illumination variation throughout the year impacts the surface reflectance by producing higher values for low solar zenith angles and lower reflectance for large zenith angles. In this work, we present a model to derive the bidirectional reflectance distribution function (BRDF) normalization and apply it to the HLS product at 30 m spatial resolution. It is based on the BRDF parameters estimated from the MODerate Resolution Imaging Spectroradiometer (MODIS) surface reflectance product (M{O,Y}D09) at 1 km spatial resolution using the VJB method (Vermote et al., 2009). Unsupervised classification (segmentation) of HLS images is used to disaggregate the BRDF parameters to the HLS spatial resolution and to build a BRDF parameters database at HLS scale. We first test the proposed BRDF normalization for different solar zenith angles over two homogeneous sites, in particular one desert and one Peruvian Amazon forest. The proposed method reduces both the correlation with the solar zenith angle and the coefficient of variation (CV) of the reflectance time series in the red and near infrared bands to 4% in forest and keeps a low CV of 3% to 4% for the deserts. Additionally, we assess the impact of the view zenith angle (VZA) in an area of the Brazilian Amazon forest close to the equator, where impact of the angular variation is stronger because it occurs in the principal plane. The directional reflectance shows a strong dependency with the VZA. The current HLS BRDF correction reduces this dependency but still shows an under-correction, especially in the near infrared, while the proposed method shows no dependency with the view angles. We also evaluate the BRDF parameters using field surface albedo measurements as a reference over seven different sites of the US surface radiation budget observing network (SURFRAD) and five sites of the Australian OzFlux network. View Full-Text
Keywords: HLS; Landsat; Sentinel 2; BRDF; albedo; SURFRAD; OzFlux HLS; Landsat; Sentinel 2; BRDF; albedo; SURFRAD; OzFlux
Show Figures

Figure 1

MDPI and ACS Style

Franch, B.; Vermote, E.; Skakun, S.; Roger, J.-C.; Masek, J.; Ju, J.; Villaescusa-Nadal, J.L.; Santamaria-Artigas, A. A Method for Landsat and Sentinel 2 (HLS) BRDF Normalization. Remote Sens. 2019, 11, 632.

AMA Style

Franch B, Vermote E, Skakun S, Roger J-C, Masek J, Ju J, Villaescusa-Nadal JL, Santamaria-Artigas A. A Method for Landsat and Sentinel 2 (HLS) BRDF Normalization. Remote Sensing. 2019; 11(6):632.

Chicago/Turabian Style

Franch, Belen; Vermote, Eric; Skakun, Sergii; Roger, Jean-Claude; Masek, Jeffrey; Ju, Junchang; Villaescusa-Nadal, Jose L.; Santamaria-Artigas, Andres. 2019. "A Method for Landsat and Sentinel 2 (HLS) BRDF Normalization" Remote Sens. 11, no. 6: 632.

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Search more from Scilit
Back to TopTop