Analysis of BRD Components Over Major Land Types of Korea

다국어 초록 (Multilingual Abstract)

The land surface reflectance is a key parameter influencing the climate near the surface. Therefore, it must be determined with sufficient accuracy for climate change research. In particular, the characteristics of the bidirectional reflectance distribution function (BRDF) when using earth observation system (EOS) are important for normalizing the reflected solar radiation from the earth? surface. Also, wide swath satellites like SPOT/VGT (VEGETATION) permit sufficient angular sampling, but high resolution satellites are impossible to obtain sufficient angular sampling over a pixel during short period because of their narrow swath scanning. This gives a difficulty to BRDF model based reflectance normalization of high resolution satellites. The principal objective of the study is to add BRDF modeling of high resolution satellites and to supply insufficient angular sampling through identifying BRDF components from SPOT/VGT. This study is performed as the preliminary data for apply to high-resolution satellite. The study provides surface parameters by eliminating BRD effect when calculated biophysical index of plant by BRDF model. We use semi-empirical BRDF model to identify the BRD components. This study uses SPOT/VGT satellite data acquired in the S1 (daily) data. Modeled reflectance values show a good agreement with measured reflectance values from SPOT satellite. This study analyzes BRD effect components by using the NDVI (Normalized Difference Vegetation Index) and the angle components such as solar zenith angle, satellite zenith angle and relative azimuth angle. Geometric scattering kernel mainly depends on the azimuth angle variation and volumetric scattering kernel is less dependent on the azimuth angle variation. Also, forest from land cover shows the wider distribution of value than cropland, overall tendency is similar. Forest shows relatively larger value of geometric term (K1·f1) than cropland, When performed comparison between cropland and forest. Angle and NDVI value are closely related.

참고문헌 (Reference)

1 염종민, "한반도 식생에 대한 MODIS 250m 자료의 BRDF 효과에 대한 반사도 정규화" 대한원격탐사학회 21 (21): 445-456, 2005

2 Csiszar, I., "Using ADEOS/ POLDER data to reduce angular variability of NOAA/AVHRR reflectances" 76 : 399-409, 2001

3 Chopping, M. J., "Testing a LiSK BRDF model with in situ bidirectional reflectance factor measurements over semiarid grasslands" 74 : 287-312, 2000

4 Wanner, W., "On the derivation of kernels for kernel-driven models of bidirectional reflectance" 100 (100): 21077-21089, 1995

5 Duchemin, B., "Normalization of directional effects in 10-day global syntheses derived from VEGETATION/ SPOT: I. Investigation of concepts based on simulation" 81 : 90-100, 2002

6 Strahler, A. H., "Modeling bidirectional reflectance of forests and woodlands using Boolean models and geometric optics" 34 : 153-166, 1990

7 J. R. Jensen, "Intoductory digital image processing: A remote sensing perspective" Englewood Cliffs 316-, 1995

8 Tarpley, J. D., "Global vegetation indices from the NOAA-7 meteorological satellite" 23 : 491-494, 1984

9 Kimes, D. S., "Directional reflectance factor distributions for cover types of Northern Africa" 18 : 1-19, 1985

10 Holben, Brent N., "Characteristics of maximumvalue composite images from temporal AVHRR data" 7 (7): 1417-1434, 1986

11 Justice, C. O., "Analysis of the phenology of global vegetation using meteorological data" 6 (6): 1271-1381, 1985

12 Jiang, Z., "Analysis of NDVI and scaled difference vegetation index retrievals of vegetation fraction" 101 (101): 366-378, 2006

13 Jong-Min Yeom, "An Efficiency Analysis for Data Synthesis of Sun- and Geo-Synchronous Satellites in Kernel-driven BRDF Model" 한국기상학회 45 (45): 499-511, 2009

14 J. A. Hartigan, "Algorithm As 135: A K-means clustering algorithm" 28 : 100-108, 1979

15 Walthall, C. L., "A study of reflectance anisotropy and canopy structure using a simple empirical model" 61 : 118-128, 1985

16 Gao, W., "A simple bidirectional-reflectance model applied to a tallgrass canopy" 45 : 209-224, 1993

17 Roujean, J. L., "A bidirectional reflectance model of the earth’s surface for the correction of remote sensing data" 97 : 20455-20458, 1992