development of meris lake water algorithms...

Antonio Ruiz-Verdú(1) *,Sampsa Koponen(2), Thomas Heege(3), Roland Doerffer(4), Carsten Brockmann(5),

Kari Kallio(6), Timo Pyhälahti(6), Ramón Peña(1), Ángel Polvorinos(7),Jörg Heblinski(3), Pasi Ylöstalo(6), Laura Conde(1), Daniel Odermatt(8),

Victor Estellés(9) and Jouni Pulliainen(10)

DEVELOPMENT OF MERIS LAKE WATER ALGORITHMS: VALIDATION RESULTS FROM EUROPE

* Currently at: INTA (Spain)E-mail [email protected]

2nd MERIS/(A)ATSR User Workshop. 22-26 September 2008 ESA/ESRIN

(1) Centre for Hydrographic Studies - CEDEX (2) Helsinki University of Technology (TKK)(3) EOMAP GmbH & Co.KG(4) GKSS Forschungszentrum Geesthacht(5) Brockmann Consult(6) Finnish Environment Institute (SYKE), (7) University of Sevilla, (8) University of Zurich - Irchel, (9) University of Valencia, (10) Finnish Meteorological Institute (FMI),


OUTLINE

1. Introduction

2. Algorithm overview

3. Validation campaigns

4. Validation results

5. Conclusions


1. Introduction

ESA ITT: Development of MERIS Lake Water Algorithms(“MERIS LAKES”). January 2007 – June 2008

http://www.space.tkk.fi/research/projects/water_quality_monitoring/MERIS_Lakes.html

MAIN TASKS:

• Algorithm development (Lake water processors)

• Implementation as a BEAM plug-in module

• Validation of the processors

Results at:http://www.brockmann-consult.de/beam-wiki/display/LAKES/Home



L1 TOA Radiances, O3, Surface Pressure, Solar Irradiance (TOA)

Atmospheric correction(AC) neural network (NN)

R_Lw (water leaving reflectance)

L_path Transmittance AOT Å coeff.

Solar and observation angles

BIO-OPTICALMODELS

NN Case 2 Regional (C2R)

NN Boreal Lakes (BL)

NN EutrophicLakes (EUL)

Concentrations of Water quality variables, IOPs, quality indicatorVAL

VAL



Summary of Processor’s products

• Path radiance reflectance, R_Lpath (9 bands)• Transmittance (9 bands)• Aerosol optical thickness (AOT)• Angstrom coefficient

Water leaving radiance reflectance, R_Lw (9 bands)

Chlorophyll concentration (Chl-a)Total Suspended Matter concentration (TSM)CDOM (gelbstoff) absorption coeff (a_gelb)*

Scattering coefficient of TSM at 443 nm (b_tsm)Phytoplankton absorption coeff. at 443 nm (a_pig)Total absorption coeff. at 443 nm (a_total)

Min. Irrad. atenuattion coeff. (K_min)Signal depth (Z_90_max)Chi_square

Validation sites


3. Validation campaigns

Finland, 4 lakes

Lake Constance

Spain, 5 lakes

Gradient of water types and SIOPs

Low Low toto moderatemoderate ChlChl--aaModerateModerate toto highhigh CDOMCDOM

Low Low ChlChl--aaAreasAreas ofof moderatemoderate TSMTSM

ModerateModerate toto veryvery highhigh ChlChl--aaCyanobacteriaCyanobacteria frequentfrequent


3. Validation campaignsMAIN MEASUREMENTS

AOPs: Above and in waterradiometry (ASD, Ramses)

IOPs in situ: absorption andscattering (Wetlabs ac-s, ac-9); backscattering (ECO bb9)

IOPs lab: Filter pad method

WQ constituents: Chl-a (HPLC or spectrophotometric), TSM (gravimetric), CDOM (spectrophotometric)

Atmosphere: Cimel 318NE in situ; Aeronet



ATMOSPHERIC CORRECTION

Two products were validated with in situ data:

ICOL (Improved Contrast between Ocean and Land)Correction method for the Adjacency EffectNot yet released as a Beam plug-inSanter R., Zagolski F., and Gilson M. (2007). Université du

Littoral, France, ICOL ATBD, Version 0.1, Feb. 28, 2007.

L1 L_TOA NN AC R_Lw

L1 L_TOA ICOL R_LwNN AC(Pre-processedwith ICOL)




400

450

500

550

600

650

700

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

0.0035

0.0040

Station LA April 13 2007, Lake Constance

RS

Ref

lect

ance

(+0)

wavelength [nm]

C2R v125, 9 pixels ICOL C2R, 9 pixels RAMSES radiometer

IZNÁJAR, STATION A, 2007-07-04

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

400 500 600 700 800 900Wavelength (nm)

RLw

(sr-

1)

IN SITUEULICOL+EUL

LAKE CONSTANCELAKE CONSTANCE((GermanyGermany))

IZNIZNÁÁJAR RESERVOIRJAR RESERVOIR((SpainSpain))


400 450 500 550 600 650 700 750 800 850 9000

1

2

3

4

5

6

7x 10-3

R w

ater

leav

ing

Wavelength (nm)

S1 BORS2 BORS3 BORS1 ICOL BORS2 ICOL BORS3 ICOL BORS1 insituS2 insituS3 insitu



LAKES LAKES VESIJVESIJÄÄRVI and PRVI and PÄÄIJIJÄÄNNENNE((FinlandFinland))

ALMENDRA, STATION A, 2007-07-10

0.000

0.002

0.004

0.006

0.008

0.010

0.012

400 500 600 700 800 900Wavelength (nm)

RLw

(sr-

1)

FIELDEULICOL+EUL

ALMENDRA RESERVOIRALMENDRA RESERVOIR((SpainSpain))



WATER QUALITY PRODUCTS

TSM (mg/l)

y = 1.28x - 0.65R2 = 0.64

0.0

2.0

4.0

6.0

8.0

0.0 2.0 4.0 6.0

IN SITUM

ERIS

BL

GERFINSPA

TSM (mg/l)

y = 1.28x - 0.65R2 = 0.64

0.0

2.0

4.0

6.0

8.0

0.0 2.0 4.0 6.0

IN SITUM

ERIS

BL

GERFINSPA

TSM (mg/l)

y = 2.33x - 1.47R2 = 0.74

0.0

2.0

4.0

6.0

8.0

10.0

0.0 2.0 4.0 6.0

IN SITU

MER

IS C

2R

GERFINSPA

TSM (mg/l)

y = 2.33x - 1.47R2 = 0.74

0.0

2.0

4.0

6.0

8.0

10.0

0.0 2.0 4.0 6.0

IN SITU

MER

IS C

2R

GERFINSPA

BOREAL PROCESSORBOREAL PROCESSORC2R PROCESSORC2R PROCESSOR



WATER QUALITY PRODUCTS

Chl-a (mg/m3)

y = 1.26x + 0.55R2 = 0.46

0.0

2.0

4.0

6.0

8.0

10.0

12.0

0.0 2.0 4.0 6.0 8.0

IN SITUM

ERIS

EU

L

GERFINSPA

Chl-a (mg/m3)

y = 1.26x + 0.55R2 = 0.46

0.0

2.0

4.0

6.0

8.0

10.0

12.0

0.0 2.0 4.0 6.0 8.0

IN SITUM

ERIS

EU

L

GERFINSPA

Chl-a (mg/m3)

y = 2.21x - 1.39R2 = 0.57

0.0

3.0

6.0

9.0

12.0

15.0

18.0

0.0 2.0 4.0 6.0 8.0

IN SITU

MER

IS C

2R

GERFINSPA

Chl-a (mg/m3)

y = 2.21x - 1.39R2 = 0.57

0.0

3.0

6.0

9.0

12.0

15.0

18.0

0.0 2.0 4.0 6.0 8.0

IN SITU

MER

IS C

2R

GERFINSPA

EUTROPHIC PROCESSOREUTROPHIC PROCESSORC2R PROCESSORC2R PROCESSOR


4. Validation resultsWATER QUALITY PRODUCTS

13 April 2008 16 April 2008 20 April 2008C2R processor, version 1.2.5 080525 0.26

0.2

0.1

0.02

AOD 550nm[1/m]

TSM [g/m3]

12520.8

0.02

85

21

0.5

Chl a [mg/m3]

0.150.1

0.05

0.030.02

aCDOMa_gelb

[1/m]

13 April 2008 16 April 2008 20 April 2008C2R processor, version 1.2.5 080525

13 April 2008 16 April 2008 20 April 200813 April 2008 16 April 2008 20 April 2008C2R processor, version 1.2.5 080525 0.26

0.2

0.1

0.02

AOD 550nm[1/m]

TSM [g/m3]

12520.8

0.02

85

21

0.5

Chl a [mg/m3]

0.150.1

0.05

0.030.02

aCDOMa_gelb

[1/m]

0.26

0.2

0.1

0.02

AOD 550nm[1/m]

0.26

0.2

0.1

0.02

AOD 550nm[1/m]

TSM [g/m3]

12520.8

0.02

85

21

0.5

Chl a [mg/m3]

0.150.1

0.05

0.030.02

aCDOMa_gelb

[1/m]

WaterWater QualityQuality mapsmaps. . LakeLake ConstanceConstance


1.2

0.8

2.0

2.6

In situ

0.24 Paa

0.44 S3

1.3 S2

2.2 S1

MERIS

June 4, 2007

1.2

0.8

2.0

2.6

In situ

0.24 Paa

0.44 S3

1.3 S2

2.2 S1

MERIS

June 4, 2007

4. Validation resultsWATER QUALITY PRODUCTS

TSM TSM mapmap. . FinlandFinland


5. Conclusions (1)

1. Atmospheric correctionGood agreement in green-red bandsGeneral improvement with ICOLDeviations in very humic or high chl-a lakes

2. Water constituentsLinear response, some over- and underestimationsAcceptable errors at low concentration rangesLarger errors in turbid lakes


5. Conclusions (2)

First Lake Water Processor for MERIS

Available at Beam Visat 4.2

3 processors for different water types (user decides)

Flexible: Easy tuning for other water types possible


Thank you for your attention!

Antonio Ruiz-Verdú(1) *,Sampsa Koponen(2), Thomas Heege(3), Roland Doerffer(4), Carsten Brockmann(5),

Kari Kallio(6), Timo Pyhälahti(6), Ramón Peña(1), Ángel Polvorinos(7),Jörg Heblinski(3), Pasi Ylöstalo(6), Laura Conde(1), Daniel Odermatt(8),

Victor Estellés(9) and Jouni Pulliainen(10)

DEVELOPMENT OF MERIS LAKE WATER ALGORITHMS: VALIDATION RESULTS FROM EUROPE

* Currently at: INTA (Spain)E-mail [email protected]


(1) Centre for Hydrographic Studies - CEDEX (2) Helsinki University of Technology (TKK)(3) EOMAP GmbH & Co.KG(4) GKSS Forschungszentrum Geesthacht(5) Brockmann Consult(6) Finnish Environment Institute (SYKE), (7) University of Sevilla, (8) University of Zurich - Irchel, (9) University of Valencia, (10) Finnish Meteorological Institute (FMI),

development of meris lake water algorithms...

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