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The Use of High Spectral Resolution Bands for Estimating Absorbed Photosynthetically Active Radiation (A Par)Most remote sensing estimations of vegetation variables such as Leaf Area Index (LAI), Absorbed Photosynthetically Active Radiation (APAR), and phytomass are made using broad band sensors with a bandwidth of approximately 100 nm. However, high resolution spectrometers are available and have not been fully exploited for the purpose of improving estimates of vegetation variables. A study directed to investigate the use of high spectral resolution spectroscopy for remote sensing estimates of APAR in vegetation canopies in the presence of nonphotosynthetic background materials such as soil and leaf litter is presented. A high spectral resolution method defined as the Chlorophyll Absorption Ratio Index (CARI) was developed for minimizing the effects of nonphotosynthetic materials in the remote estimates of APAR. CARI utilizes three bands at 550, 670, and 700 nm with bandwidth of 10 nm. Simulated canopy reflectance of a range of LAI were generated with the SAIL model using measurements of 42 different soil types as canopy background. CARI obtained from the simulated canopy reflectance was compared with the broad band vegetation indices (Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), and Simple Ratio (SR)). CARI reduced the effect of nonphotosynthetic background materials in the assessment of vegetation canopy APAR more effectively than broad band vegetation indices.
Document ID
19950010604
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Kim, Moon S.
(Maryland Univ. College Park, MD, United States)
Daughtry, C. S. T.
(Agricultural Research Service (ARS) Beltsville, MD, United States)
Chappelle, E. W.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Mcmurtrey, J. E.
(Agricultural Research Service (ARS) Beltsville, MD, United States)
Walthall, C. L.
(Maryland Univ. College Park, MD, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1994
Publication Information
Publication: CNES, Proceedings of 6th International Symposium on Physical Measurements and Signatures in Remote Sensing
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
GSFC-E-DAA-TN72921
Accession Number
95N17019
Distribution Limits
Public
Copyright
Public Use Permitted.
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