ALOS URGENT OBSERVATION - RESULTS FROM THE TOHOKU-OKI M9.0 EARTHQUAKE AND THE RELATED

DISASTERS

Masanobu Shimada, Manabu Watanabe,

Takeshi Motohka, Masato Ohki

JAXA

Content

1. AVNIR-2 image

2. PALSAR amplitude image

3. PALSAR interferometry

4. PALSAR Full polarimetry

1. ANVIR-2 image

2011/2/27 2011/3/14

Flooded areas due to tsunami was clearly observed.

2. ＰＡＬＳＡＲ Amplitude imageR : Jun. 21, 2008(47.8)GB: Mar. 13, 2011(46.6)

Damage of windbreak forest

3. ＰＡＬＳＡＲinterfelometry

Ascending Descending

4. ＰＡＬＳＡＲFull polarimetry

Apr. 8, 2011ＪＡＸＡ/METI

After the disasterObs. date：Apr., 8, 2011

Before the disasterObs. date: Nov. 21, 2010

Off-nadir angle : 21.5°

Direction ：Ascending

Ishinomakicity

Region 1(Minamihama-machi)

Region 2(Nakaura, Shintate)

Region 3(Kamihama)

April 8, 2011 Four component decompositioin R: Double G: Volume B: Surface

Tsunami area mapGeospatial information authority of JapanAreas of collapsed building

due to tsunami

Geospatial information authority of Japan

Region 1 (Before the disaster) Region 1 (After the disaster)

Region 2 Region 3

Aerial photos

Region 3Region 2

Region 1

Photos taken on the ground

November 21, 2010 April 8, 2011

α angleRegion 1 (Minamihama-machi)

November 21, 2010 April 8, 2011

0HH

(Full polarimetry, resolution : 30m)

JAXA, METI

Region 1

Region 2

Region 3

(FBS (HH), resolution : 10m)0

HH

R : Nov. 12, 2009, off-nadir angle of 41.5 GB: Mar. 16, 2011, off-nadir angle of 43.4

Coherence

Before the disaster After the disaster

|HH-VV| : Increaseafter the disaster

| RR-LL| : Decreaseafter the disaster

High : UrbanLow : Vegetation, Bare soilSchuler D. S., Lee J. S., and Degrandi G. : Electonic Proc. EUSAR2006, May 2006

Reflection symmetry

2

VVHH

2

HV

2

VVHH

2

HV

SSS4

SSS40

RRLL

Region 1

Coherence of reflection symmetric target

Blue: Before the disaster Red: After the disaster

Little reflection symmetry characteristics are observed for building collapsed areas.

Re

Im RR-LL

H//AnisotropyAnisotropy : Decreaseafter the disaster

: Decreaseafter the disaster

Approaching surface scattering

Higher H(0.60.8)in both case.

Urban -> Collapsed building= change of 2 and 3 (eigenvalues)

But …

()

Anisotropy Pauli

PALSAR

PiSAR(L-band)

Anisotropy shows“difference”

Collapsed

Anisotropy shows“no difference“

Due to azimuth slope angle ?

Flight direction

Flight direction

Non collapsed

Collapsed

Non collapsed

Apr. 8

Apr. 13

4-componentdecomposition

0

Volume scattering 0HH

No systematic difference observed!

Due to azimuth slope angle?

Power (dB) 0HH (dB)

Google Earth 2011/04/06

Before the disaster

2002/11/29

Pi-SAR-L 2011/04/13

Inundated paddy field

(PiSAR L-band)

1 km

Bright spot in paddy field

scrap, cars, etc…

(PiSAR L-band)

100 m

Google Earth 2011/04/06

Pi-SAR-L 2011/04/13

Four component decomposition

Evacuated cars around a park(PALSAR)

2011040820101121

Summary Show ALOS urgent observation results.

(AVNIR-2 , PALSAR amplitude image, PALSAR interferometry) Compare full polarimetric parameters before and after the disaster over areas of collapsed building due to tsunami

1σ difference |HH-VV| , |RR-LL| , α angle, Anisotropy (not observed for PiSAR)

0.5 σ difference 4-component (but not systematic)

No significant difference

Polarization Orientation angle,HH-VV phase, entropy,σ0（ＨＨ，ＨＶ，ＶＶ）

Collapsed building : Surface scattering with high entropy& non-reflection symmetry