Comparison of ground and satellite based measurements of the fraction of photosynthetically active radiation intercepted by tall-grass prairie

Journal Article · Sun Nov 01 04:00:00 EST 1992 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JD00877· OSTI ID:6115852

Demetriades-shah, T H; Kanemasu, E T; Flitcroft, I D; Su, H ^[1]

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1. Georgia Univ., Griffin (United States) Kansas State Univ., Manhattan (United States)

The fraction of photosynthetically active radiation intercepted by vegetation, F(sub ipar) is an important parameter for modeling the interactions between the land-surface and atmosphere and for estimating vegetation biomass productivity. This study was, therefore, an integral part of FIFE. The specific purpose of this experiment was to find out how well definitive measurements of F(sub ipar) on the ground relate to near-ground and satellite based spectral reflectance measurements. Concurrent measurements of F(sub ipar) and ground, helicopter, and satellite based reflectance measurements were taken at thirteen tall-grass prairie sites within the FIFE experimental area. The sites were subjected to various combinations of burning and grazing managements. The ground and helicopter based reflectance measurements were taken on the same day or few days from the time of the overpass of LANDSAT and SPOT satellites. Ground-based reflectance measurements and sun photometer readings taken at the times of the satellite overpasses were used to correct for atmospheric attenuation. Hand-held radiometer spectral indices were strongly correlated with helicopter and satellite based values (r = 0.94 for helicopter, 0.93 for LANDSAT Thematic Mapper, and 0.86 for SPOT). However, the ground, helicopter, and satellite based normalized difference spectral vegetation indices showed low sensitivity to changes in F(sub ipar). Reflectance measurements were only moderately well correlated with measurements of F(sub ipar) (r = 0.82 for hand-held radiometer, 0.84 for helicopter measurements, and 0.75 for the LANDSAT Thematic Mapper and SPOT). Improved spectral indices which can compensate for site differences are needed in order to monitor F(sub ipar) more reliably. 12 refs.

• Research Organization: National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center
• OSTI ID: 6115852
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 97:D17; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

440101 -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AERIAL MONITORING
BIOMASS
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
ECOSYSTEMS
ENERGY SOURCES
EVALUATION
MEASURING INSTRUMENTS
MONITORING
OPTICAL PROPERTIES
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYSICAL PROPERTIES
PLANTS
RADIATION DETECTORS
RADIATION EFFECTS
RADIATIONS
RADIOMETERS
RANGELANDS
REMOTE SENSING
RENEWABLE ENERGY SOURCES
SOLAR RADIATION
SPECTRAL REFLECTANCE
STELLAR RADIATION
SYNTHESIS
TERRESTRIAL ECOSYSTEMS