The bidirectional effects of AVHRR measurements over boreal regions
Abstract
Northern ecosystems play an important role in regional and global weather and climate. The objectives of this paper are to analyze the bidirectional effects of satellite data over six land-cover types in northern regions, and to test a method for the routine correction of these effects. Analyses and corrections were carried out with both single-day and 10-day composite data obtained by the advanced very high resolution radiometer (AVHRR) from central Canada acquired in 1993/1994, in part, for the boreal ecosystem and atmosphere study (BOREAS). The model of Wu et al. developed from a separate data set collected at lower latitudes, was employed for correcting the effects. Using the model of Wu et al., the BRDF-related variability is reduced by about 68% in channel 1 and 71% in channel 2. After a simple adjustment of the model coefficients, a further reduction of 4% (channel 1) and 6% (channel 2) of the BRDF-related variability was achieved for the 10{sup 6} km{sup 2} BOREAS region. The effectiveness of the correction with both original and refined model of Wu et al. was found to be weakly dependent on land-cover type. Corrections for coniferous, mixed wood, and cropland are better than other land-cover types (rangelands/pasture,more »
- Authors:
-
- Canada Centre for Remote Sensing, Ottawa, Ontario (Canada)
- Publication Date:
- OSTI Identifier:
- 419614
- Resource Type:
- Journal Article
- Journal Name:
- IEEE Transactions on Geoscience and Remote Sensing
- Additional Journal Information:
- Journal Volume: 34; Journal Issue: 6; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 54 ENVIRONMENTAL SCIENCES; CLIMATIC CHANGE; BOREAL REGIONS; CLIMATES; TERRESTRIAL ECOSYSTEMS; REMOTE SENSING; REGIONAL ANALYSIS; RADIOMETERS
Citation Formats
Li, Z, Cihlar, J, Zheng, X, Moreau, L, and Ly, H. The bidirectional effects of AVHRR measurements over boreal regions. United States: N. p., 1996.
Web.
Li, Z, Cihlar, J, Zheng, X, Moreau, L, & Ly, H. The bidirectional effects of AVHRR measurements over boreal regions. United States.
Li, Z, Cihlar, J, Zheng, X, Moreau, L, and Ly, H. 1996.
"The bidirectional effects of AVHRR measurements over boreal regions". United States.
@article{osti_419614,
title = {The bidirectional effects of AVHRR measurements over boreal regions},
author = {Li, Z and Cihlar, J and Zheng, X and Moreau, L and Ly, H},
abstractNote = {Northern ecosystems play an important role in regional and global weather and climate. The objectives of this paper are to analyze the bidirectional effects of satellite data over six land-cover types in northern regions, and to test a method for the routine correction of these effects. Analyses and corrections were carried out with both single-day and 10-day composite data obtained by the advanced very high resolution radiometer (AVHRR) from central Canada acquired in 1993/1994, in part, for the boreal ecosystem and atmosphere study (BOREAS). The model of Wu et al. developed from a separate data set collected at lower latitudes, was employed for correcting the effects. Using the model of Wu et al., the BRDF-related variability is reduced by about 68% in channel 1 and 71% in channel 2. After a simple adjustment of the model coefficients, a further reduction of 4% (channel 1) and 6% (channel 2) of the BRDF-related variability was achieved for the 10{sup 6} km{sup 2} BOREAS region. The effectiveness of the correction with both original and refined model of Wu et al. was found to be weakly dependent on land-cover type. Corrections for coniferous, mixed wood, and cropland are better than other land-cover types (rangelands/pasture, deciduous, and transitional forests) with residual BRDF errors around 0.05 in both channels. Overall, the model performs reasonably well throughout the growing season. To apply the model, only general knowledge of land-cover type is required, namely forest, cropland, grassland, and bare ground.},
doi = {},
url = {https://www.osti.gov/biblio/419614},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
number = 6,
volume = 34,
place = {United States},
year = {Fri Nov 01 00:00:00 EST 1996},
month = {Fri Nov 01 00:00:00 EST 1996}
}