Transcript 슬라이드 1 - Kangwon

Polarimetric Characteristics of Fully Polarization SAR Image
Observed by Ground-Based SAR System
Moon-Kyung Kang1*, Kwang-Eun Kim2, Hoonyol Lee3, Seong-Jun Cho4 and Jae-Hee Lee5
1,2,4,5 Korea
Institute of Geoscience and Mineral Resources, Daejeon, Republic of Korea, *[email protected]
3,5 Department of Geophysics, Kangwon National University, Suncheon, Republic of Korea
 INTRODUCTION
 RESULTS
 Ground-Based SAR (GB-SAR) systems
 monitoring tools for agriculture, terrain mapping, man-made structures
 ground surface deformation detection and displacement measurement
 dams, bridges, and so on
 using SAR interferometric techniques.
 SAR Polarimetry Technique
 for analysis of more detailed physical and biophysical features of various surface
target
 understanding of scattering characteristics about a single or distributed targets.
 Many researchers have been interested in classification, decomposition, and modelling
of polarimetric SAR data in recent literature.
 The objective behind efforts is better understanding about the scattering
mechanism that give rise to the polarimetric characteristics seen in SAR image data.
 The purpose of this paper
 This work was focused on application study of the developed GB-SAR system based
on SAR polarimetry techniques as a preliminary study.
 analyzing the dominant scattering properties about different surface targets such as
trees, grasses, a human-made structure, and several permanent scatterers
 using H/A/Alpha polarimetric decomposition algorithms.
 Alpha parameter
α-> 0 : a single scattering (rough surface)
α -> 45 : volume scattering
α -> 90 : double-bounce scattering
0
 Entropy (H) parameter
H=0 : a pure target
H=1 : truly a random noise process
90
0
1
 An example of Wishat-H/A/Alpha classification (#_41)
 METHODOLOGY
 GB-SAR System
1 2 3 4 5 6 7 8
 Test site
 Korea Institute of Geoscience and
Mineral Resources (KIGAM) field
 for operation and performance test of
GB-SAR system
 Five permanent scatterers
 Measurement Date: 3-5 November, 2008
(a) Wishart-H/Alpha classification
1 2 3 4 5 6 7 8 9 10 11 12 13 1415 16
(c) Wishart-H/A/Alpha classification
5.3 GHz (C-band)
Range bandwidth
600 MHz
IF BW
1 KHz
Number of point
1601
Power
VNA 0 dBm, Amp 33 dBm
Azimuth step
5 cm
Azimuth length
5m
Polarization
HH, HV, VH, VV
 Used software
 SAR focusing processing: ‘gbsar’ processor (by Kangwon National University)
 PolSAR processing: ‘PolSARpro’ open software package
(http://envisat.esa.int/polsarpro)
 The main PolSAR processing
 H/A/Alpha decomposition and analysis
 Unsupervised Wishart – H/A/Alpha classification
 RESULTS
Ps_1 Ps_2
Ps_3
 The dominant colors over grass and
trees areas
-> pink, white, green, blue
 white -> equal amplitude over all
polarimetric channel
 green -> a dominant HV component
 pink-magenta -> VV, HH > HV
 5 permanent scatterers
 white and magenta
Ps_4
Ps_5
Grass Area
Lexicographic (Sinclair) color coded
image (R: VV, G: HV, B: HH) at #_41
Temperature (℃)
Temperature (℃)
(a)
20
15
10
5
0
3
#_155
Phase Variation (ps-1)
#_7
#_80
1
0
1
5
9
13
17
21
25
29
33
37
41
45
49
53
57
61
65
69
73
77
81
85
89
93
97
101
105
109
113
117
121
125
129
133
137
141
145
149
153
157
Variation (radian)
2
2008/11/03 13:04 ~ 2008/11/05 16:52
(b)
-1
-2
-3
#_56
Measurement Number
1 2 3 4 5 6 7 8 9 10 11 12 131415 16
(d) Wishart-H/A/Alpha1 classification
Test site (KIGAM)
 Image Processing
25
(b) Wishart-H/Alpha1 classification
 Temporal variation: Wishart-H/A/Alpha1 classification Results
Center frequency
Trees Area
1 2 3 4 5 6 7 8
HH_pha
#_130
HV_pha
VH_pha
VV_pha
 (a) atmosphere temperature
variation graph during entire
measurement period
 (b) phase variation graph of
HH, HV, VH and VV
polarizations at a permanent
scatterer (ps_1)
 (a) and (b) graphs show
similar distribution
1 2 3 4 5 6 7 8 9 10 11 12 13 1415 16
1 2 3 4 5 6 7 8 9 10 11 12 13 1415 16
(a) #_7
1 2 3 4 5 6 7 8 9 10 11 12 13 1415 16
(a) #_56
1 2 3 4 5 6 7 8 9 10 11 12 13 1415 16
(c) #_80
(d) #_130
 CONCLUSIONS
 The objective of this study has been to assess a geophysical application of fully
polarimetric SAR data measured by the GB-SAR system in order to extracting relevant
information about surface scattering properties.
 From the classification results, we can consider that the dominant scattering property
of different surface targets such as natural or man-made targets varies depending on
target’s material types and their environmental conditions.
 It is expected that GB-SAR system will be a convenient tool for measurement and
analysis of polarimetic properties for various target on the Earth.
 ACKNOWLEDGEMENTS
This research was supported by a grant (07KLSGC03) from Cutting-edge Urban
Development - Korean Land Spatialization Research Project funded by Ministry of Land,
transport and Maritime Affairs of Korean government.
 REFERENCES
Lee, J.-S. and Pottier, E., 2009. Polarimetric Radar Imaging From Basics to Applications, CRC Press.
Lee, H., Cho, S.-J., Sung, N.-H., and Kim, J.-H., 2007a. Development of a GB-SAR (I): System Configuration
and Interferometry, Korean Journal of Remote Sensing, 23(4), pp. 237-245.
Lee, H., Cho, S.-J., Sung, N.-H., and Kim, J.-H., 2007b. Development of a GB-SAR (II): Focusing Algorithms,
Korean Journal of Remote Sensing, 23(4), pp. 247-256.