Open AccessEstimation of vegetation canopy leaf area index and fraction of absorbed photosynthetically active radiation from atmosphere‐corrected MISR data
Author(s) -
Knyazikhin Y.,
Martonchik J. V.,
Diner D. J.,
Myneni R. B.,
Verstraete M.,
Pinty B.,
Gobron N.
Publication year - 1998
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/98jd02461
Subject(s) - photosynthetically active radiation , spectroradiometer , leaf area index , remote sensing , environmental science , biome , endmember , canopy , moderate resolution imaging spectroradiometer , understory , vegetation (pathology) , data set , hyperspectral imaging , computer science , reflectivity , geology , satellite , optics , geography , physics , ecosystem , artificial intelligence , ecology , archaeology , pathology , biology , photosynthesis , medicine , botany , astronomy
The multiangle imaging spectroradiometer (MISR) instrument is designed to provide global imagery at nine discrete viewing angles and four visible/near‐infrared spectral bands. This paper describes an algorithm for the retrieval of leaf area index (LAI) and fraction of photosynthetically active radiation absorbed by vegetation (FPAR) from atmospherically corrected MISR data. The proposed algorithm is designed to utilize all the information provided by this instrument, using a two‐step process. The first step involves a comparison of the retrieved spectral hemispherically integrated reflectances with those determined from the model which depend on biome type, canopy structure, and soil/understory reflectances. The biome/canopy/soil/understory models that pass this comparison test are subject to the second step, which is a comparison of their directional reflectances at the MISR angles to the retrieved spectral directional reflectances. This procedure, however, can produce multiple acceptable solutions. The measure theory is used to specify the most probable values of LAI and FPAR using the set of all acceptable solutions. Optimization of the retrieval technique for efficient global processing is discussed. This paper is the second of a two‐part set describing a synergistic algorithm for producing global LAI and FPAR fields from canopy reflectance data provided by the MODIS (moderate resolution imaging spectroradiometer) and MISR instruments.