IGARSS2011-BIOMASS_Kostas_v1.ppt

Microwaves and Radar InstituteMicrowaves and Radar Institute

Potential & Challenges of Pol-InSAR Techniques for Forest Height Estimation in the context of the BIOMASS Mission

S-K. Lee, S. Sauer, F. Kugler, R. Scheiber, I. Hajnsek & K. Papathanassiou

German Aerospace Center (DLR)

Microwaves and Radar Institute (DLR-HR)

VU 2 > Autor Name

Microwaves and Radar Institute > 30.05.2006Microwaves and Radar InstituteMicrowaves and Radar Institute

26 Plots / 27m x 32m / la= 0.6

58.1a H66.1lB ⋅=

Motivation

Sungai WainLowland Dipterocarp Forest

Mawas 1Riverine Peat Swamp Forest

Mawas 2Tropical Peat Swamp Forest

20 Plots / 10m x 10m / la= 0.5 20 Plots / 10m x 10m / la= 0.6

Insufficient Number of samples !!! - But clear trend visible !!!

VU 3 > Autor Name


21 SS><><

><=

∗∗

∗

2211

2121

SSSS

SS)SS(γ~Interferometric

Coherence

VolumeCoherence

∫

∫=

v

v

z

oz

h

o

h

o

zik

zikVol

dz)z(f

dze)z(f

e))z(f(γ~

)z(f

)z(f … vertical reflectivity function

Vol

ume

Coh

eren

ce

00V

~

II

γ =

∫

∫

=

=

V

V

h

0 00

h

0 0z

'dzθcos

'zσ2expI

'dzθcos

'zσ2exp)'zκiexp(I

0V

G

I)w(m

)w(m)w(m

=

Vertical Wavenumber:

G/V Ratio:

)θsin(

θΔκκ

0z =

Volume Height

Extinction

Topography

G/V Ratio

Vh

σ

0φ

)w(m

)w(m1

)w(mγ~)φiexp()w(γ 0V

0

~

++=)zz(δm

θcoszσ2

expσ)z(f 0G0

0V −′+

=

2 Layer Scattering Model

VU 4 > Autor Name


Phase Center Location as a Function of Polarisation / Ground

Var

ian

ce o

f th

e P

ha

se C

ente

r L

oca

tio

n d

ue

to

Vo

lum

e, S

yste

m a

nd

Tem

po

ral

Dec

orr

elat

ion

The Effect of the Ground-2-Volume Component

Ground and Volume No Ground

Only VolumeVolume only

)κ|σ,h(γ~)κ|(γ~)φiexp(min zV0VzVol0σ,hV

−−

)φiexp()m(γ~ 0Vol =∞=

0V0Vol γ~)φiexp()0m(γ~ ==

VU 5 > Autor Name


Campaigns Summary

Lidar4 - 6m / .5 -.730º-45ºFlatMultiple >2 15minManaged

Semi BorealBIOSAR-I

Lidar4.5m / .6530º-50ºHillyMultiple >215min BorealBIOSAR-II

Lidar1.9m / .9530°-45°Locally Slopes

Multiple >215 minTemperateTempoSAR

Stand< 2m30°-40°Flat115 minManaged

TemperateNezer Forest

Lidar2.m / .9435º-40ºFlat320minPeat Swamp INDREX-II

Stands2-3m40ºHilly220min(Lowland)

Dipterocarp INDREX-II

30-40º

IncidenceAngle

2,5m(Preliminary)

ResultsRMS / ρ2

15 min + …

Temporal Baseline

StandHilly1TropicalTropiSAR

TerrainForestCampaign Reference

SpatialBaselines

VU 6 > Autor Name


Ground-2-Volume Ratios Range

INDREX-II: 1402; Mawas

INDREX-II: 0601; Sungai Wain

mmax

mmin

VU 7 > Autor Name


Ground-2-Volume Ratios Range

BioSAR 2007: 0401; Remningstorp

BioSAR 2008: 0103; Krycklan

mmax

mmin

VU 8 > Autor Name


P-band

P-band

Model Miss-Match of Vertical Structure Function (f(z))

)z(f

)z(f

50

40

30

20

10

0m

MAWAS

Krycklan

Forest Height

Forest Height

LIDAR H100 (m)

LIDAR H100 (m)

VU 9 > Autor Name


σ > 0m3= 0

σ > 0m3≠ 0

σ >< 0m3= 0

σ >< 0m3≠ 0

Effect of Extinction and Ground-to-Volume Ratio

VU 10 > Autor Name


Campaigns Summary Temporal Deco

1-7d

2 / 4 / 7 / 14 / 20 / 22d

1 - 15d

1 / 30 / 56d

20min

Temporal Baseline

0.94 / 0.85 / 0.90 / 0.80 / 0.92 / 0.90TropicalTropiSAR

0.95 - 0.95Managed

TemperateTempoSAR

Tropical

Managed Semi Boreal

Peat Swamp

Forest

La Selva

BIOSAR-I

INDREX-II

Campaign

Lidar

Lidar

Comments

0.6-0.8

0.95 / 0.9 / 0.85

0.93

Temporal Decorrelation

10m20m30m

)w(m1

)w(mγ~γ~γ~)φiexp()w(γ TGVTV

0

~

++=)zz(δmeσ)z(f 0G

θcoszσ2

0V0 −′+=

2 Layer Model with Temporal Decorrelation

Extinction

Vol

ume

Coh

eren

ce

0V I

Iγ =~

∫

∫

=

=

V

V

h

0 00

h

0 0z

'dzθcos

'zσ2expI

'dzθcos

'zσ2exp)'zκiexp(I

Volume Height

Topography

G/V Ratio

Vh

0φ)w(m

σ0V

G

I)w(m

)w(m)w(m

=

)θsin(

θΔκκ

0z =

TG

TV

γ~γ~ Temp. Deco. Volume

Temp. Deco. Ground

VU 11 > Autor Name


Campaigns Summary Temporal Deco

1-7d

2 / 4 / 7 / 14 / 20 / 22d

1 - 15d

1 / 30 / 56d

20min

Temporal Baseline

0.94 / 0.85 / 0.90 / 0.80 / 0.92 / 0.90TropicalTropiSAR

0.95 - 0.95Managed

TemperateTempoSAR

Tropical

Managed Semi Boreal

Peat Swamp

Forest

La Selva

BIOSAR-I

INDREX-II

Campaign

Lidar

Lidar

Comments

0.6-0.8

0.95 / 0.9 / 0.85

0.93

Temporal Decorrelation

10m20m30m

)φiexp(γ~lim)m(γ~ 0Volm

Vol ==∞=∞→

0VDeco0Vol γ~γ)φiexp()0m(γ~ ⋅⋅==

1|)m(γ~| Vol =∞=with

)w(m1

)w(m)σ,h,κ(γ~γ)φiexp()γ,w,κ(γ~ Vz0VTV

0TVz

++⋅=

Volume Coherence & Decorrelation

VU 12 > Autor Name


\

From Air 2 Space-Borne

Incidence Angle: 25º-60º 20º-30º

Spat. Baselines: - Multiple Multiple

- Variable (0. < Kz < 0.2) Only limited variable

Tmp. Baselines: Minutes – Hours 25-45 Days !!!

System Bandwidth: ~100MHz 6MHz

Spatial Resolution: 2.0-3.0m Ground Range 50m Ground Range

1.5-3.0m Azimuth 25m Azimuth

Ionosphere: No Yes

Atmosphere: No Yes

VU 13 > Autor Name


Decorrelation Modeling

)φiexp()m(γ~ 0Vol =∞= )]φφ(iexp[)m(γ~)φiexp( D0VolD +=∞=

0VzDecoD0VolzDecoD γ~)κ(γ)]φφ(iexp[)0m(γ~)κ(γ)φiexp( +==

)κ(γ)]φφ(iexp[)m(γ~)κ(γ)φiexp( zDecoD0VolzDecoD +=∞=

0V0Vol γ~)φiexp()0m(γ~ == 0VD0VolD γ~)]φφ(iexp[)0m(γ~)φiexp( +==

|)κ(γ~|)φiexp()κ(γ~ zDecoDzDeco =

)φiexp()κ(γ~ DzDeco =

Phase Screens

Phase & Amplitude Deco

)κ|w(γ~)κ(γ~:)κ|w(γ~ zVolzDecoz

=

)κ|w(γ~)κ(γ~:)κ|w(γ~ zVolzDecoz

=

VU 14 > Autor Name


Deterioration of Resolution (P-band BIOSAR)

Original airborne resolution(2m x 5m Multilook)

Degraded resolution(50m x 50m Multilook)

VU 15 > Autor Name


BIOSAR-I: Interferometric Coherence History

100MHz 6MHz

HH Channel

6MHz + NESZ + Ambiguities T-deco = 0.9

Co

he

ren

ce

6MH

z

Coherence 100MHz

VU 16 > Autor Name


BIOSAR-I: Interferometric Coherence History

100MHz 6MHz

HH Channel

6MHz + NESZ + Ambiguities T-deco = 0.9

VU 17 > Autor Name


Mawas Test Site / INDREX-II

HV Amplitude 100MHz 6MHz



Remningstorp Test Site

Kryckland Test Site

Mawas Test Site

VU 18 > Autor Name


BIOSAR-I: Single & Dual Baseline Inversion of Forest Height

Single baseline inversion; Original data (100MHz)i

Single baseline inversion; Spaceborne scenario (6MHz)i

Single baseline inversion; Spaceborne scenario + T-deco

Dual baseline inversion; Spaceborne scenario + T-deco

VU 19 > Autor Name


P-band Pol-InSAR Conclusions

PolInSAR measures forest top height (H100) without the need of any a priory knowledge:

A quantity compatible with forestry standards;

A physical (not radar) quantity therefore independent of incident angle / environmental effects.

Demonstration / Validation at P-band over many sites across all major forest ecosystems:

Tropical, Boreal, Temperate;

Flat / Sloped (moderate ►steep) terrain;

Height ranges 5-60m / Biomass levels: 100-500T/Ha !!!

Pol-InSAR forest height inversion at P-band provides stable forest height maps.

Overall performance: RMS: 1.9 to 6m (10-30%) p2: 0.9-0.5

Larger variation of vertical scatterer distribution(s) across forest types.

Lower vegetation attenuation and larger / wider range of Ground-to-Volume Scat. Ratios;

Decreased sensitivity of P-band to the vegetation layer;

The performance depends critically on the selection of the (spatial) baseline. For reaching the inversion performance across a range of forest heights (5 ►50m) multiple baselines are required

VU 20 > Autor Name


P-band Pol-InSAR Conclusions

The performance in space will be affected primarily by ► temporal decorrelation and ► the limited ability to provide variable (and large) spatial baselines.

Inversion performance analysis predict a overal performance between 20-100%. ► 20-40% with an optimised acquisition scenario across a height range from 10 to 60-70m on a 100x100m raster.

Critical areas: Positive terrain slopes and heterogeneous forest situations.

Bio & Geo-Physical Parameter Retrieval Algorithm Definition for Active Remote Sensing at P- & L-bandFinal Report ESA Contract 21131/07/NL/LvH, 2010.

Microwaves and Radar InstituteMicrowaves and Radar Institute

Potential & Challenges of Pol-InSAR Techniques for Forest Height Estimation in the context of the BIOMASS Mission

S-K. Lee, S. Sauer, F. Kugler, R. Scheiber, I. Hajnsek & K. Papathanassiou

German Aerospace Center (DLR)

Microwaves and Radar Institute (DLR-HR)

IGARSS2011-BIOMASS_Kostas_v1.ppt

Technology

campaign lidar lidar

volume coherence decorrelation

temperate nezer forest

volume ratios range

temporal baseline

tropical peat swamp

campaigns summary lidar

volume ratios range