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Estimation of tropical forest biomass with image texture of radar images

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HAL Id: hal-02810299

https://hal.inrae.fr/hal-02810299

Submitted on 6 Jun 2020

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Estimation of tropical forest biomass with image texture of radar images

Isabelle Champion, Jean-Pierre da Costa, Adrien Godineau, Ludovic Villard, Pascale Dubois-Fernandez, Thuy Le Toan

To cite this version:

Isabelle Champion, Jean-Pierre da Costa, Adrien Godineau, Ludovic Villard, Pascale Dubois- Fernandez, et al.. Estimation of tropical forest biomass with image texture of radar images. 32.

EARSel Symposium, May 2012, Mykonos, Greece. n.p. �hal-02810299�

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Estimation of tropical forest biomass using image texture of radar images

Isabelle Champion 1

J P Da Costa

2

, A Godineau

2

, L Villard

3

, P Dubois- Fernandez

4

and T Le Toan

3

1

INRA, UR1263 EPHYSE, Villenave D’Ornon, France

2

CNRS, UMR 5218 IMS, Talence, Fr.

3

CESBIO, CNRS-CNES- Univ P Sabatier, Toulouse, France

4

ONERA, Salon de Provence - BA 701, France

(3)

PARACOU experimental site in French Guiana

Question :

quantifying global carbon fluxes ?

forest biomass retrieving

(4)

SAR acquisitions with the airborne ONERA SETHI system fully polarimetric images at X, L, P band

From Dubois-Fernandez et al., 2010

(5)

Paracou: 15 measured experimental plots

6 control plots

3 sets of 3 plot each

with various thinning levels

Biomass ranges

from 266.7 to 466 t.ha

-1

(6)

N W E

S

100x100 pixels windows are selected in the SAR image 2 sets of texture features are calculated for each window:

features characterizing the basckscattering distribution (variance, skewness, kurtosis, entropy)

features based on the grey level co-occurrence matrix or GLCM (variance, energy, contrast, entropy…) (Haralick, 1973) (pairs of horizontal joined pixels, 32 levels)

P band, HV SAR image

(7)

Texture features vs plot biomass regressions

from σ° distribution from GLCM

200 250 300 350 400 450 500

-20 -18 -16 -14 -12 -10

stand age : R²=0.0061848 t student=0.28443

mean intensity =-0.0018564*age +-14.9347

200 250 300 350 400 450 500

25 30 35 40 45

stand age : R²=0.18654 t student=1.7266

variance =0.017775*age +29.9739

200 250 300 350 400 450 500

-3.2 -3 -2.8 -2.6 -2.4 -2.2 -2 -1.8

stand age : R²=0.013026 t student=0.41422

S/N =0.00033269*age +-2.7051

200 250 300 350 400 450 500

-240 -220 -200 -180 -160 -140

stand age : R²=0.1254 t student=1.3653

skewness =-0.087409*age +-160.912

200 250 300 350 400 450 500

3000 4000 5000 6000 7000 8000 9000

stand age : R²=0.28054 t student=2.2515

kurtosis =6.6972*age +3713.7131

200 250 300 350 400 450 500

50 100 150 200 250

stand age : R²=0.13016 t student=1.3948

entropy =0.14569*age +98.1743

200 250 300 350 400 450 500

1400 1600 1800 2000 2200 2400

stand age : R²=0.0014838 t student=0.13899

variance =0.11565*age +1887.231

200 250 300 350 400 450 500

200 400 600 800 1000 1200

stand age : R²=0.11381 t student=1.2921

energy =0.7345*age +516.9401

200 250 300 350 400 450 500

250 300 350 400 450 500 550

stand age : R²=0.20052 t student=1.8057

contrast =-0.29226*age +479.4216

200 250 300 350 400 450 500

0.84 0.86 0.88 0.9 0.92 0.94 0.96

stand age : R²=0.089521 t student=1.1306

correlat =8.4044e-005*age +0.87167

200 250 300 350 400 450 500

-44 -42 -40 -38 -36 -34

stand age : R²=0.14703 t student=1.4969

entropy1 =-0.0091006*age +-35.4468

200 250 300 350 400 450 500

1.8 2 2.2 2.4 2.6 2.8 3 3.2

stand age : R²=0.19535 t student=1.7765

homog =0.0015253*age +1.9579

(8)

Texture features vs plot biomass regressions

from σ° distribution from GLCM

200 250 300 350 400 450 500

-20 -18 -16 -14 -12 -10

stand age : R²=0.0061848 t student=0.28443

mean intensity =-0.0018564*age +-14.9347

200 250 300 350 400 450 500

25 30 35 40 45

stand age : R²=0.18654 t student=1.7266

variance =0.017775*age +29.9739

200 250 300 350 400 450 500

-3.2 -3 -2.8 -2.6 -2.4 -2.2 -2 -1.8

stand age : R²=0.013026 t student=0.41422

S/N =0.00033269*age +-2.7051

200 250 300 350 400 450 500

-240 -220 -200 -180 -160 -140

stand age : R²=0.1254 t student=1.3653

skewness =-0.087409*age +-160.912

200 250 300 350 400 450 500

3000 4000 5000 6000 7000 8000 9000

stand age : R²=0.28054 t student=2.2515

kurtosis =6.6972*age +3713.7131

200 250 300 350 400 450 500

50 100 150 200 250

stand age : R²=0.13016 t student=1.3948

entropy =0.14569*age +98.1743

200 250 300 350 400 450 500

1400 1600 1800 2000 2200 2400

stand age : R²=0.0014838 t student=0.13899

variance =0.11565*age +1887.231

200 250 300 350 400 450 500

200 400 600 800 1000 1200

stand age : R²=0.11381 t student=1.2921

energy =0.7345*age +516.9401

200 250 300 350 400 450 500

250 300 350 400 450 500 550

stand age : R²=0.20052 t student=1.8057

contrast =-0.29226*age +479.4216

200 250 300 350 400 450 500

0.84 0.86 0.88 0.9 0.92 0.94 0.96

stand age : R²=0.089521 t student=1.1306

correlat =8.4044e-005*age +0.87167

200 250 300 350 400 450 500

-44 -42 -40 -38 -36 -34

stand age : R²=0.14703 t student=1.4969

entropy1 =-0.0091006*age +-35.4468

200 250 300 350 400 450 500

1.8 2 2.2 2.4 2.6 2.8 3 3.2

stand age : R²=0.19535 t student=1.7765

homog =0.0015253*age +1.9579

(9)

Texture features:

1) from σ° distribution 2) From GLCM

kurtosis R²=0.28 contrast R²=0.20

Correlation is poor: dispersion is large with respect to biomass range !

Structural characteristics of plots

200 250 300 350 400 450 500

3000 4000 5000 6000 7000 8000 9000

estimated biomass : R²=0.28054 t student=2.2515

kurtosis =6.6972*biomass +3713.7131

200 250 300 350 400 450 500

250 300 350 400 450 500 550

estimated biomass : R²=0.20052 t student=1.8057

contrast =-0.29226*biomass +479.4216

(10)

Plots are settled in a hilly landscape

Topographical classes for the 6 control plots P1, P6, P11, P13, P14, P15

Bottomlands Hillsides

Hilltops

From F. Morneau, 2007

(11)

Edaphic constraints influence floristic composition and stand structure

Plots were characterized by their trunk dbh class distributions Block 1 small P1,

intermediate P2, big: P3, P8

Block 2 intermediate and big P6, P7, P10, P12

Block 3 small P4, P5, P9, P11

From Gourlet-Fleury et al., 2004

(12)

Edaphic constraints influences canopy structure of plots Plots are characterized by their trunk dbh distribution

Block 1 small P1, intermediate P2, big: P3, P8

Block 2 intermediate and big P6, P7, P10, P12

Block 3 small P4, P5, P9, P11

S small, I intermediate, B big, IB intermediate and big S1, I2, B3, S5, IB6, IB7, B8, S9, IB10, S11, IB12

and unknown

13, 14, 15

(13)

Texture features (GLCM) : entropy vs variance

S small,

I intermediate,

IG, intermediate and big, B big

No structural information P13, P14, P15

1500 1600 1700 1800 1900 2000 2100 2200 2300

-42 -41 -40 -39 -38 -37 -36

variance

entropy

S1 I2

B3 S5 S4

IB7 IB6 B8

S9

IB10

S11 IB12

13 14

15

(14)

Texture features (GLCM): entropy vs variance

B big

IB, intermediate and big,

differ from

S small and I intermediate, with P13, P14, P15

Apart P3…

1500 1600 1700 1800 1900 2000 2100 2200 2300

-42 -41 -40 -39 -38 -37 -36

variance

entropy

S1 I2

B3 S5 S4

IB7 IB6 B8

S9

IB10

S11 IB12

13 14

15

(15)

Texture indicator:

GLCM-based

statistics with two structural classes

O : Big trees + : Small trees

200 250 300 350 400 450 500

1400 1600 1800 2000 2200

biomass

variance

200 250 300 350 400 450 500

500 600 700 800 900 1000

biomass

energy

200 250 300 350 400 450 500

300 350 400 450

biomass

contrast

200 250 300 350 400 450 500

0.87 0.88 0.89 0.9 0.91 0.92 0.93

biomass

correlat

200 250 300 350 400 450 500

-41 -40 -39 -38 -37 -36

biomass

entropy1

200 250 300 350 400 450 500

2 2.2 2.4 2.6 2.8 3

biomass

homog

(16)

Retrieving biomass accounting for structural classes

discrimination of structural classes ?

variation with topography and soil ?

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