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Sun-view angle effects on reflectance factors of corn canopiesThe effects of sun and view angles on reflectance factors of corn (Zea mays L.) canopies ranging from the six leaf stage to harvest maturity were studied on the Purdue University Agronomy Farm by a multiband radiometer. The two methods of acquiring spectral data, the truck system and the tower systrem, are described. The analysis of the spectral data is presented in three parts: solar angle effects on reflectance factors viewed at nadir; solar angle effects on reflectance factors viewed at a fixed sun angle; and both sun and view angles effect on reflectance factors. The analysis revealed that for nadir-viewed reflectance factors there is a strong solar angle dependence in all spectral bands for canopies with low leaf area index. Reflectance factors observed from the sun angle at different view azimuth angles showed that the position of the sensor relative to the sun is important in determining angular reflectance characteristics. For both sun and view angles, reflectance factors are maximized when the sensor view direction is towards the sun.
Document ID
19860025753
Document Type
Reprint (Version printed in journal)
Authors
Ranson, K. J. (Purdue Univ. West Lafayette, IN, United States)
Daughtry, C. S. T. (Purdue Univ. West Lafayette, IN, United States)
Biehl, L. L. (Purdue Univ. West Lafayette, IN, United States)
Bauer, M. E. (Purdue University West Lafayette, IN, United States)
Date Acquired
August 12, 2013
Publication Date
October 1, 1985
Publication Information
Publication: Remote Sensing of Environment
Volume: 18
ISSN: 0034-4257
Subject Category
EARTH RESOURCES AND REMOTE SENSING
Funding Number(s)
CONTRACT_GRANT: NAS9-16528
Distribution Limits
Public
Copyright
Other