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United States Department of Agriculture

Agricultural Research Service

Title: Variability and Covariance of Factors Affecting Canopy with Reflectance Within a 6 Ha Corn Field

Authors
item Walthall, Charles
item Daughtry, Craig
item Loechel, Sara - UNIVERSITY OF MARYLAND
item Dulaney, Wayne
item Timlin, Dennis

Submitted to: IEEE IGARSS Annual Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 1, 2000
Publication Date: July 24, 2000

Interpretive Summary: Our understanding of the mechanisms of reflectance as measured by remote sensing devices is formalized through plant reflectance simulation models. An assumption of these models is that the input factors, such as foliage density, leaf reflectance, leaf transmittance, and canopy height, are independent. These assumptions are tested using data taken from a 6 ha corn field in Beltsville, MD. Relationships between leaf reflectance and transmittance were evident, however, not 1:1. Foliage density expressed as leaf area index (LAI) was found to be slightly correlated with leaf reflectance and transmittance. LAI was also found to be slightly correlated with canopy height. By using these trends to better define possible factor combinations, improvements in simulations should be possible. This information will be of use to anyone using plant canopy reflectance simulation models to retrieve information from remote sensing data, such as large area crop yield analysts.

Technical Abstract: Optimization of remote sensing procedures for agriculture will require more information about the factors affecting crop reflectance. For canopy reflectance simulation purposes, factors such as foliage density, leaf reflectance, leaf transmittance, and height, are considered independent and have not been measured extensively over areas larger than small plots. This study addressed this assumption seeking to determine correlations between the factors for a 6 ha corn field in Beltsville, MD. Relationships between leaf reflectance and transmittance were evident, however, not 1:1. Foliage density expressed as leaf area index (LAI) was found to be slightly correlated with leaf reflectance and transmittance. LAI was also found to be slightly correlated with canopy height. This information will be of use to analysts using inversion of canopy reflectance simulation models to retrieve LAI as part of crop yield inventory surveys and to researchers using simulations models.

Last Modified: 10/25/2014
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