TY - JOUR
T1 - Reflectance and transmission properties of West African savanna trees from ground radiometer measurements
AU - Franklin, J.
AU - Prince, S. D.
AU - Strahler, A. H.
AU - Hanan, N. P.
AU - Simonett, D. S.
N1 - Funding Information:
Dramane Demb616 and Dramane Diarra assisted with the field measurements. Pierre Hiernaux provided the radiometer, along with sage advice and comments. Measurements were taken in the International Livestock Centre for Africa (lLCA) study sites with the permission of the Director, Dr. Abdelkader Diallo, as part of their research programme. Measurements were taken in the Region of Segou with the authorization of the National Ministry of Education, Republic of Mali. This work was supported by NASA grants NAGW-788 and NGT05-010-8, by the Food
PY - 1991/6
Y1 - 1991/6
N2 - Reflectance and transmission properties of savanna trees were mea-sured using a pole-mounted radiometer for four Sahelian and two Sudanian species in West Africa. The measurements showed that canopy spectral compo-nents, that is, shadowed and sunlit tree crown and background, have distinct reflectance characteristics in red and infrared wavebands as modelled by Li and Strahler (1985). Sunlit canopy is the greenest component (greatest infrared to red contrast), and sunlit background (consisting mostly of bare soil), the brightest (greatest summed red and infrared reflectance). Shadowed crown, the darkest component, is greener than shadowed background. The field radiometer measurements were used to calculate the normalized difference vegetation index (NDVI), and the spatial integral of the NDVI over the canopy was related to crown volume yielding per species r2 of 0.75 to 0.81. Measurements of canopy transmission indicated that only 12 to 47 per cent of incoming radiation was absorbed in these wavebands.
AB - Reflectance and transmission properties of savanna trees were mea-sured using a pole-mounted radiometer for four Sahelian and two Sudanian species in West Africa. The measurements showed that canopy spectral compo-nents, that is, shadowed and sunlit tree crown and background, have distinct reflectance characteristics in red and infrared wavebands as modelled by Li and Strahler (1985). Sunlit canopy is the greenest component (greatest infrared to red contrast), and sunlit background (consisting mostly of bare soil), the brightest (greatest summed red and infrared reflectance). Shadowed crown, the darkest component, is greener than shadowed background. The field radiometer measurements were used to calculate the normalized difference vegetation index (NDVI), and the spatial integral of the NDVI over the canopy was related to crown volume yielding per species r2 of 0.75 to 0.81. Measurements of canopy transmission indicated that only 12 to 47 per cent of incoming radiation was absorbed in these wavebands.
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U2 - 10.1080/01431169108929731
DO - 10.1080/01431169108929731
M3 - Article
AN - SCOPUS:0025920178
SN - 0143-1161
VL - 12
SP - 1369
EP - 1385
JO - International Journal of Remote Sensing
JF - International Journal of Remote Sensing
IS - 6
ER -