Estimation and Validation of RapidEye-Based Time-Seriesof Leaf Area Index for Winter Wheat in the RurCatchment (Germany)

Remote Sensing

卷:7

Muhammad Ali¹  Carsten Montzka¹  Harry Vereecken¹  Frank Thonfeld²  Anja Stadler³  Gunter Menz⁴ 

[1] Agrosphere (IBG-3), Research Center Jülich GmbH, Wilhelm-Johnen-Straße, 52428 Jülich, Germany;

[2] Centre for Remote Sensing of Land Surfaces (ZFL), University of Bonn, Walter-Flex-Straße 3, 53115 Bonn, Germany;

[3] Institute of Crop Science and Resource Conservation, University of Bonn, Katzenburgweg 5,53115 Bonn, Germany;

[4] Remote Sensing Research Group, Department of Geography, University of Bonn, Meckenheimer Allee 166, 53115 Bonn, Germany;

关键词: leaf area index;    red-edge band;    RapidEye;    atmospheric correction;    validation;    time-series;   

DOI  :  10.3390/rs70302808

来源: DOAJ

【 摘 要 】

Leaf Area Index (LAI) is an important variable for numerous processes in various disciplines of bio- and geosciences. In situ measurements are the most accurate source of LAI among the LAI measuring methods, but the in situ measurements have the limitation of being labor intensive and site specific. For spatial-explicit applications (from regional to continental scales), satellite remote sensing is a promising source for obtaining LAI with different spatial resolutions. However, satellite-derived LAI measurements using empirical models require calibration and validation with the in situ measurements. In this study, we attempted to validate a direct LAI retrieval method from remotely sensed images (RapidEye) with in situ LAI (LAIdestr). Remote sensing LAI (LAIrapideye) were derived using different vegetation indices, namely SAVI (Soil Adjusted Vegetation Index) and NDVI (Normalized Difference Vegetation Index). Additionally, applicability of the newly available red-edge band (RE) was also analyzed through Normalized Difference Red-Edge index (NDRE) and Soil Adjusted Red-Edge index (SARE). The LAIrapideye obtained from vegetation indices with red-edge band showed better correlation with LAIdestr (r = 0.88 and Root Mean Square Devation, RMSD = 1.01 & 0.92). This study also investigated the need to apply radiometric/atmospheric correction methods to the time-series of RapidEye Level 3A data prior to LAI estimation. Analysis of the the RapidEye Level 3A data set showed that application of the radiometric/atmospheric correction did not improve correlation of the estimated LAI with in situ LAI.

【 授权许可】

Unknown