Next Article in Journal
Incorporation of Passive Microwave Brightness Temperatures in the ECMWF Soil Moisture Analysis
Previous Article in Journal
Comparison and Validation of Long Time Serial Global GEOV1 and Regional Australian MODIS Fractional Vegetation Cover Products Over the Australian Continent
Open AccessArticle

Global-Scale Evaluation of Roughness Effects on C-Band AMSR-E Observations

1
State Key Laboratory of Remote Sensing Science, and School of Geography, Beijing Normal University, Beijing 100875, China
2
INRA, UMR 1391 ISPA, Villenave d’Ornon, INRA, Bordeaux Aquitaine 33140, France
3
Centre d’Etudes Spatiales de la BIOsphere (CESBIO), UMR 5126, (CNES, CNRS, IRD, UT3), Toulouse Cedex 31401, France
4
Climatology from Satellites Group, Department of Earth Physics & Thermodynamics, Faculty of Physics, University of Valencia, Burjassot 46100, Spain
5
Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100094, China
*
Authors to whom correspondence should be addressed.
Academic Editors: Nicolas Baghdadi and Prasad S. Thenkabail
Remote Sens. 2015, 7(5), 5734-5757; https://doi.org/10.3390/rs70505734
Received: 25 January 2015 / Revised: 21 April 2015 / Accepted: 29 April 2015 / Published: 5 May 2015
Quantifying roughness effects on ground surface emissivity is an important step in obtaining high-quality soil moisture products from large-scale passive microwave sensors. In this study, we used a semi-empirical method to evaluate roughness effects (parameterized here by the parameter) on a global scale from AMSR-E (Advanced Microwave Scanning Radiometer for EOS) observations. AMSR-E brightness temperatures at 6.9 GHz obtained from January 2009 to September 2011, together with estimations of soil moisture from the SMOS (Soil Moisture and Ocean Salinity) L3 products and of soil temperature from ECMWF’s (European Centre for Medium-range Weather Forecasting) were used as inputs in a retrieval process. In the first step, we retrieved a parameter (referred to as the parameter) accounting for the combined effects of roughness and vegetation. Then, global MODIS NDVI data were used to decouple the effects of vegetation from those of surface roughness. Finally, global maps of the Hr parameters were produced and discussed. Initial results showed that some spatial patterns in the values could be associated with the main vegetation types (higher values of were retrieved generally in forested regions, intermediate values were obtained over crops and grasslands, and lower values were obtained over shrubs and desert) and topography. For instance, over the USA, lower values of were retrieved in relatively flat regions while relatively higher values were retrieved in hilly regions. View Full-Text
Keywords: soil moisture; soil surface roughness; AMSR-E soil moisture; soil surface roughness; AMSR-E
Show Figures

Graphical abstract

MDPI and ACS Style

Wang, S.; Wigneron, J.-P.; Jiang, L.-M.; Parrens, M.; Yu, X.-Y.; Al-Yaari, A.; Ye, Q.-Y.; Fernandez-Moran, R.; Ji, W.; Kerr, Y. Global-Scale Evaluation of Roughness Effects on C-Band AMSR-E Observations. Remote Sens. 2015, 7, 5734-5757.

Show more citation formats Show less citations formats

Article Access Map by Country/Region

1
Only visits after 24 November 2015 are recorded.
Search more from Scilit
 
Search
Back to TopTop