agri_tdx_igarss2011_hajnsek_comp_final.pdf

IGARSS’11, Vancouver

TanDEM-X: Pol-InSAR over Agricultural Areas

*Irena Hajnsek, Kostas Papathanassiou, Florian Kugler

Microwaves and Radar Institute, DLR Oberpfaffenhofen, Germany

* Institute of Environmental Engineering, ETH Zurich, Switzerland

Slide 2

Agricultural Parameter Estimation: Current Research Status

Scat

Mechanisms

Developed

Methods Physical Products Observables

Research

Status

Bare surface

(surface

scattering,

dihedral scat.)

X-Bragg Soil Moisture Content

Soil Roughness

Soil Penetration Depth

PolSAR

@ longer l

medium

mature

Vegetated

surface

(surface,

dihedral,

volume scat.)

Decomposition

Theorems

Topography

Soil Moisture Content

Soil Roughness

PolSAR

Pol-InSAR

D-InSAR

@ longer l

low

mature

Vegetation

volume

(volume,

dihedral scat.)

RVoGM

OVoGM

PCT

Vegetation Height

Vegetation Extinction

Vegetation Structure

Vegetation Biomass

PolSAR

InSAR

Pol-InSAR

@ shorter l

low

mature

Slide 3


Scat

Mechanisms

Developed


Research

Status

Bare surface

(surface

scattering,

dihedral scat.)


Soil Roughness


PolSAR

@ longer l

medium

mature

Vegetated

surface

(surface,

dihedral,

volume scat.)

Decomposition

Theorems

Topography


Soil Roughness

PolSAR

Pol-InSAR

D-InSAR

@ longer l

low

mature

Vegetation

volume

(volume,

dihedral scat.)

RVoGM

OVoGM

PCT

Vegetation Height



Vegetation Biomass

PolSAR

InSAR

Pol-InSAR

@ shorter l

low

mature

Slide 4


Scat

Mechanisms

Developed


Research

Status

Bare surface

(surface

scattering,

dihedral scat.)


Soil Roughness


PolSAR

@ longer l

medium

mature

Vegetated

surface

(surface,

dihedral,

volume scat.)

Decomposition

Theorems

Topography


Soil Roughness

PolSAR

Pol-InSAR

D-InSAR

@ longer l

low

mature

Vegetation

volume

(volume,

dihedral scat.)

RVoGM

OVoGM

PCT

Vegetation Height



Vegetation Biomass

PolSAR

InSAR

Pol-InSAR

@ shorter l

low

mature

Slide 5


Scat

Mechanisms

Developed


Research

Status

Bare surface

(surface

scattering,

dihedral scat.)


Soil Roughness


PolSAR

@ longer l

medium

mature

Vegetated

surface

(surface,

dihedral,

volume scat.)

Decomposition

Theorems

Topography


Soil Roughness

PolSAR

Pol-InSAR

D-InSAR

@ longer l

low

mature

Vegetation

volume

(volume,

dihedral scat.)

RVoGM

OVoGM

PCT

Vegetation Height



Vegetation Biomass

PolSAR

InSAR

Pol-InSAR

@ shorter l

low

mature

Slide 6

Kz Range for Agricultural Applications

Adapted to TanDEM-X system configuration

Incidence angle fixed for 30 degree

For a crop height of 1-2.5m a kz between

2-3 provides the best sensitivity

Slide 7

Kz Range Translated into Baseline (TanDEM-X Configuration)

For a kz of 2-3 baselines from 2-3km would be ideal corresponding to a

height of ambiguity of ~ 2-3m.

Slide 8

1 km

rape winter wheat

maize

Agricultural Test Site Wallerfing (North of Munich)

Acqu. Dates Comments / Ground Campaign HOA/baseline/kz

12.04 acquired, no on-site measurements 38m/133m/0.047

23.04 acquired, no on-site measurements --

04.05 acquired, on-site measurements 33m/153m/0.041



06.06 corrupted --

17.06 acquired, no on-site measurements --

28.06 acquired, on-site measurements --

09.07 planed --

20.07 planed --

31.07 planed --

11.08 planed --

22.08 planed --

Slide 9

Site Overview – Phenology 04. May 2011 (blue marks: soil moisture; yellow marks: vegetation & partly soil moisture)

height = 0 cm height = 26 cm height = 131 cm

maize winter wheat rape seed

Slide 10

Site overview – Phenology 15./26. May 2011

height = 5 cm

height = 25 cm height = 51 cm

height = 126 cm height = 36 cm

height = 133

cm

maize winter wheat rape seed

Slide 11

Temperature and Precipitation

0

5

10

15

20

25

01/04/

11

08/04/

11

15/04/

11

22/04/

11

29/04/

11

06/05/

11

13/05/

11

20/05/

11

27/05/

11

date

tem

pe

ratu

re [°C

]

0

5

10

15

20

25

30

pre

cip

ita

tio

n [m

m]

RAINSUM

TA200AVG

TS005AVG

Meteo Data: Daily Precipitation 01.04.-31.05.2011

Data take

© StMELF Agrarmeteo

Slide 12

TanDEM-X: Dual-Pol InSAR: First Bistatic Data Takes

Test Site: Wallerfing, Germany

Date: 12/04

Year: 2011

Pol: HH & VV

Stripmap Mode

Slide 13



Date: 04/05

Year: 2011

Pol: HH & VV

Stripmap Mode

Slide 14



Date: 15/05

Year: 2011

Pol: HH & VV

Stripmap Mode

Slide 15



Date: 26/05

Year: 2011

Pol: HH & VV

Stripmap Mode

Slide 16

12.04.2011

26.05.2011 15.05.2011

04.05.2011

2-Dim Polarimetric

Scattering Entropy

Slide 17

12.04.2011

26.05.2011 15.05.2011

04.05.2011

2-Dim Polarimetric

Scattering Angle

α=0°

α=90°

α=45°

Slide 18

SNR correction

Interferometric coherence VV-Pol


04/05/2011

Slide 19

SNR correction Coherence VV 4th May 2011

VV

VV

HH

HH

Terra SAR-X

TanDEM-X

NESZ Polynomials (from xml files)


04/05/2011

Slide 20

Pol-InSAR SNR Correction


before SNR correction


after SNR correction

Test Site: Wallerfing, Germany 04.05.2011

Slide 21

Pol-InSAR SNR Correction

Interferometric coherence HH-Pol

before SNR correction

Interferometric coherence HH-Pol

after SNR correction


Slide 22

VV Coherence

12.04.2011

26.05.2011 15.05.2011

04.05.2011

Slide 23

HH Coherence

12.04.2011

26.05.2011 15.05.2011

04.05.2011

Slide 24

Max Coherence

12.04.2011

26.05.2011 15.05.2011

04.05.2011

Slide 25

Min Coherence

12.04.2011

26.05.2011 15.05.2011

04.05.2011

Slide 26

Pol-InSAR SNR Masking

Interferometric coherence Max Interferometric coherence Min


Slide 27


Interferometric coherence Max Interferometric coherence Min


Slide 28


12.04.2011 26.05.2011 15.05.2011 04.05.2011

Slide 29

InSAR Coherence VV-pol: Zoom for Field Selection

04/05

12/04

15/05

26/05

Slide 30

Statistics of the InSAR Coherence (3 Fields)

Interferometric coherence measured as a mean over the entire field

Red: rape,

Green: corn,

Blue: wheat

Red: rape,

Green: corn,

Blue: wheat

Slide 31

Dual Pol-InSAR: Maximum Phase Difference Estimation

Interferometric Coherence: at polarisation

i22ii11i

iiii

w]T[ww]T[w

w]Ω[w)w,w(γ~

)w,w(γ~ ii

iw

Cb,awbwaw)w,w(γ~ VVHHiii

)w,w(γ~ maxmax

)w,w(γ~ minmin

Coherence Region:

Max. Phase diff. between polarisations

Slide 32

Dual Pol-InSAR: Max Height Difference

12.04.2011

26.05.2011

15.05.2011

04.05.2011

Slide 33

Statistics of the Max Phase Difference & Height Difference

Red: rape

Green: corn

Blue: wheat

Red: rape

Green: corn

Blue: wheat

Main problem:

Too low kz

Very short vegetation

Solution:

Special 3-4 months TanDEM-X phase for growing crops

(hopefully in the third year)

Slide 34

First Pol-InSAR

Data Takes

Dual-Pol HH-VV Spotlight

Test Site Location: Russia

InSAR Mode: Monostatic

Temporal Baseline: 3sec

Spatial Baseline (┴): 275m

Slide 35

Pol-InSAR

HH-HH VV-VV

HH VV

Interferometric

Coherence

Amplitude Images

Slide 36

Pol-InSAR

0 1 2 [m] 3

Max height difference

Kz: 0.24

HOA: 26

Baseline: 252m

AOI: 39°

agri_tdx_igarss2011_hajnsek_comp_final.pdf

Technology

dihedral scat

volume scat

low mature slide

vancouver tandemx

agricultural areas

agricultural applications

switzerland slide

height of ambiguity