goals: sugianto, ray merton, shawn laffan and jon … · 2010. 11. 10. · sugianto, ray merton,...
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3rd FIG Regional Conference, Jakarta, Indonesia, October 3-7, 2004
A MultiA Multi--angular and Multiangular and Multi--temporal Study temporal Study using CHRIS Hyperspectral Imagery using CHRIS Hyperspectral Imagery
SUGIANTO, Ray MERTON, Shawn LAFFAN and Jon HUNTINGTON
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Objective
A multiA multi--angular and multiangular and multi--temporal study of temporal study of vegetation and soils using CHRIS vegetation and soils using CHRIS hyperspectralhyperspectral datadata
1.To examine the variations in spectral directional 1.To examine the variations in spectral directional reflectance of vegetation (cotton)reflectance of vegetation (cotton)
2.To study spatial variability of soil spectra2.To study spatial variability of soil spectra..3.To correlate a selection of indices from different times 3.To correlate a selection of indices from different times
and different angular measurementsand different angular measurements
Goals:
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Twynam (Colly cotton)
Field Study Site
Centered at 148°51’ E and 29°36’ S
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Images and Spectral Data Collection
1. CHRIS 1. CHRIS 2. Leaf/Cotton Spectra 2. Leaf/Cotton Spectra 3. Soil Spectra3. Soil Spectra
Spectra for Cotton Varities
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2030405060708090
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W ave lenght(nm)
Ref
lect
ance
(%)
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METHODOLOGY METHODOLOGY Image analysis & classification
Multi-angular & geometric Data
Multiangle Spectra Characteristics
Spectral ID
Multi-angular Multi-temporalHyper spectral dataset Imagery
Reduced Spatial/Spectral Data
Identified & Mapped data
Spectrally Characterized dataClass SeparabilityAnalysis
Ground TruthAccuracy Assessed Data
Statistical Analyses
Results
Vegetation & Soil Spectra
Field Multi-angular Multi-temporal Hyperspectral
Dataset
Calibration
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� Statistical analysis of image data(surface reflectance)
� Spatial analysisRegistration/geo-correction, ROI
�� Spectral Analysis Spectral Analysis -- EndEnd--member collectionmember collection-- Spectral library creation Spectral library creation -- Classification/spectral Mapping Classification/spectral Mapping ––
e.ge.g MNF, SAM, PPI, Conti. Removed,MNF, SAM, PPI, Conti. Removed,-- Index calculationsIndex calculations
�� MultiMulti--temporal analysistemporal analysis�� Functional Data Analysis (FDA)Functional Data Analysis (FDA)
CHRIS Multi-Angle Image Data Analysis
5 images
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Assumption of using MultiAssumption of using Multi--angular CHRISangular CHRIS
�� Different angle of acquisition has the different Different angle of acquisition has the different response and illumination.response and illumination.
�� MultiMulti--angular image can effect the spectral angular image can effect the spectral analysis results. analysis results.
�� CHRIS can be treated as Functional DataCHRIS can be treated as Functional Data�� How BRDF effect on vegetation and soil.How BRDF effect on vegetation and soil.
?? How this effect, let we explore early findings the How this effect, let we explore early findings the dataset analysis results. dataset analysis results.
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Radiance
Reflectance
ReflecReflec..+EFFORT+EFFORT
-- Atmospheric correction Atmospheric correction
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INITIAL RESULTS
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-- MultiMulti--angular Data Plot (soil)angular Data Plot (soil)
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55deg 36deg 0deg -36deg
-55deg
- Multi-angular Spectral Signature
Multi-angular Vegetation Spectra
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440 540 640 740 840 940
Wavelength(nm)
Ref
lect
ance
Mean_55
Mean_36
Mean_0
Mean_min36
Mean_min55
Multi-angle soil Spectra
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440 540 640 740 840 940
Wavelength
Ref
lect
ance
Mean_55
Mean_36
Mean_0
Mean_min36
Mean_min55
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-- Spectral Spectral EndmemberEndmember Mapping Mapping
�� Minimum Noise Fraction (MNF) to determine inherent image Minimum Noise Fraction (MNF) to determine inherent image datadata
�� Pixel Purity Index (PPI) to determine “pure spectra pixels”Pixel Purity Index (PPI) to determine “pure spectra pixels”�� Spectral Angle Spectral Angle MapperMapper (SAM)(SAM) to classify spectra to match to classify spectra to match
referencereference�� Mixture Tuned Matched Filtering (MTMF) to performs Mixture Tuned Matched Filtering (MTMF) to performs
matched filtering to addmatched filtering to add “infeasibility image result”“infeasibility image result”
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+55deg
+36deg
0deg
-36deg
- 55deg
MNF Eigenvalue plot
- Minimum Noise Fraction (MNF) for first 3 bands
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0 2 4 6 8 10Factor/Band
Tota
l Var
ianc
e (%
)
+55deg
+36deg
0deg
-36deg
-55deg
Percentage of Total Variance of First 10 factors of 60 MNF Bands
- MNF continued…
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MultiMulti--angle CHRIS Datasetangle CHRIS Dataset
+55o+36o
0o
-36o
-55oPixel Purity Index
n-D Visualizer
- PPI & n-D Visualizer
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- Continuum Removal of Multi-angle dataset
-- Continuum Removal of Continuum Removal of MultiMulti--angle datasetangle dataset
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+55, +36, 0, -36, -55
1.0372.685-55deg
1.2832.780-36deg
1.4553.0740deg
1.2402.882+36deg
1.2692.907+55deg
Std. DevMean ValueView Angle
SAM Classification
K-Mean
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-- Spectral Variation Within Paddocks (Soil)Spectral Variation Within Paddocks (Soil)
Field Spectra (ASD)CHRIS ImageCHRIS Image
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3
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--MultiMulti--temporal Selected Index Valuetemporal Selected Index Value
RSVI
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24-Jul 14-Jan 6-Jul 27-Dec 18-Jun 9-Dec
Temporal
RV
SI
Val
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36deg
55deg
m36deg
m55deg
Simple Rasio
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24-Jul 14-Jan 6-Jul 27-Dec 18-Jun 9-Dec
Tempral
SR
Val
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36deg
55deg
m36deg
m55deg
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NDVI Ratio
y = 0.1654x + 0.4942R2 = 0.8335
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0.00 0.20 0.40 0.60 0.80 1.00 1.20
Red-Edge Ratio
y = -0.1116x + 4.5486R2 = 0.3254
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Lab. Red_edge Value
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ld R
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val
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RNVI Value
y = -0.4464x + 5.3944R2 = 0.3615
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-1 0 1 2 3 4
Lab. value
Fie
ld v
alu
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NDVI Ratio
y = 0.1654x + 0.4942R2 = 0.8335
0.60
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0.00 0.20 0.40 0.60 0.80 1.00 1.20
Correlation of Vegetation Indexes for field spectra,laboratory spectra
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CONCLUSIONCONCLUSIONCHRIS MultiCHRIS Multi--angle dataset:angle dataset:
�� The initial investigation has shown the The initial investigation has shown the ‘angular‘angular--signature’ variation and well signature’ variation and well explored.explored.
�� Provide alternative classificationsProvide alternative classifications�� Could provide better classification resultsCould provide better classification results�� Can be used for BRDF studiesCan be used for BRDF studies�� Data function analysis possibleData function analysis possible
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The “Hyperspectral Cube” of Colly Cotton Site
HyMap (126 channels)Airborne Hyperspectral
“CHRIS” (62 Channels)Space-borne Hyperspectral