Peter Gege and Stefan Plattner MERIS validation activities ... · Peter Gege and Stefan PlattnerPeter Gege and Stefan Plattner MERIS validation activities at Lake Constance MERIS

DLR Oberpfaffenhofen, Remote Sensing Technology Institute

Peter Gege and Stefan PlattnerPeter Gege and Stefan Plattner

MERIS validation activitiesat Lake Constance

MERIS validation activitiesat Lake Constance

MERIS user workshopSession 3: MERIS water products validaton

Frascati, 11.11.2003

MERIS user workshopSession 3: MERIS water products validaton

Frascati, 11.11.2003


Lake Constance (Bodensee)Lake Constance (Bodensee)


CHRIS-PROBACHRIS-PROBA


MERISMERIS


Available DataAvailable Data

Parameter Sensor July 11 July 19 Sept. 19Lu (TOA ) MERIS x x xLu (TOA) CHRIS-PROBA x - xLu (1.8, 4.0, 5.4 km) ROSIS - x -Lu (1.8, 4.0 km) HYMAP - x -Ship coordinates GPS x x xLu+, Ed+ ZEISS x x xLu-, Eu-, Ed- RAMSES x x xOD Atmosphere MICROTOPS x x xSPM(x,z) ADCP - - xChl-a, Phao Photometer 2x 2x 1xSPM org., inorg. Balance 2x 2x 1xGelbstoff absorption Dual-beam photom. 2x 2x 1xDetritus absorption Integrating sphere x x xa*(�) Phytoplankton Integrating sphere x x xSecchi depth Secchi disk x x xCTD Multisonde - x xPhoto Digital camera x x x


Conditions at MERIS overflightsConditions at MERIS overflights

Rhine station, Sept. 19, 2003, 12:37 h

July 11 July 19 Sept. 19Overflight time (local) 12:25 11:34 12:25Data quality sunglint no L2 dataSun zenith angle (°) 28 35 47MERIS viewing angle (°) 35 34 35Aerosol-OD at 870 nm 0.064 0.054 0.082Angström exponent(Fit for 380, 440, 500, 675, 870 nm)

1.63 1.71 1.52


Variability of water constituentsVariability of water constituents

July 11 July 19 Sept. 19Number of stations (2 depths) 8 8 6Secchi depth (m) 2.9 - 4.5 2.0 - 4.7 3.1 - 3.9Chl-a + Phaeo (µg/l) 2.0 - 4.1 2.3 - 3.9 3.2 - 5.3SPM (mg/l) 1.1 - 2.0 1.2 - 3.1 1.4 - 2.0Gelbstoff (m-1 at 440 nm) 0.18 - 0.23 0.22 - 0.27 0.22 - 0.26Gelbstoff S (nm-1) 0.011-0.013 0.011-0.012 0.010-0.012


Suspended matterSuspended matter

MERIS L2 FR - Suspended Matter [g/m³]2003/09/19


Suspended matterSuspended matter

MERIS L2 FR - Suspended Matter [g/m³]

STATION TSM [g/m³]A 1.83

B1 1.67B2 1.83C 1.67

D1 1.42E 1.83

IN SITU DATA (Depth: 0.5m)

AVG TSM (ROI) SDEV (ROI)1.77 g/m³ 1.56 g/m³

MERIS FR L2

(considered Range: 0.5 - 20 g/m³)

2003/09/19


ChlorophyllChlorophyll

MERIS L2 FR - Chlorophyll a [mg/m³]2003/09/19


ChlorophyllChlorophyll

MERIS L2 FR - Chlorophyll a [mg/m³]2003/09/19

STATION CLa [mg/m³]A 3.87

B1 3.74B2 4.40C 3.47

D1 2.60E 3.69

IN SITU DATA (Depth: 0.5m)

AVG CLa (ROI) SDEV (ROI)3.64 mg/m³ 1.75 mg/m³

MERIS FR L2

(considered Range: 0.8 - 15 mg/m³)


GelbstoffGelbstoff

MERIS L2 FR - Yellow Substance [1/m]2003/09/19


GelbstoffGelbstoff

MERIS L2 FR - Yellow Substance [1/m]2003/09/19

STATION YS [1/m]A 0.353

B1 0.241B2 0.234C 0.240

D1 0.241E 0.264

IN SITU DATA (Depth: 1m)

AVG YS (ROI) SDEV (ROI)0.099 /m 0.038 /m

(considered Range: 0.01 - 0.3 /m)

MERIS FR L2


Pixel noisePixel noise

MERIS L2 FR - Suspended Matter [g/m³]

MERIS L2 FR - Chlorophyll a [mg/m³]

2003/07/15


SPM errorsSPM errors

Aerosol Optical Thickness

Suspended Matter [g/m³]

MERIS L2 FR2003/09/19

Aerosol Epsilon




Aerosol Optical Thickness Aerosol Epsilon




Aerosol Optical Thickness Aerosol Epsilon


Comparison of reflectance spectraComparison of reflectance spectra

400 500 600 700 800Wavelength (nm)

0.00

0.01

0.02

0.03

0.04

Refle

ctan

ce �

Lw /

E d

MERISMERISZEISS above surfaceZEISS above surfaceRAMSES below surfaceRAMSES below surfaceModel fitted to RAMSESModel fitted to RAMSESModel with in-situ dataModel with in-situ data

19.9.2003Station E

ZEISS

RAMSES


Comparison of reflectance spectraComparison of reflectance spectra

400 500 600 700 800Wavelength (nm)

0.00

0.01

0.02

0.03

0.04

Refle

ctan

ce �

Lu /

Ed

RAMSES below surfaceRAMSES below surfaceMERISMERIS

400 500 600 700 800Wavelength (nm)

0.00

0.01

0.02

0.03

0.04

Refle

ctan

ce �

Lu /

Ed

ZEISS above surfaceZEISS above surfaceMERISMERIS

19.9.2003, all stations


Availability of MERIS-FR dataAvailability of MERIS-FR data

MERIS-FR imagettesESA L1b L2ordered 37 37received 27 30Lake Constance covered 15 13- " - with corrupt bitmasks 14 0- " - water product missing 0 4free of errors 1 9DLR Neustrelitz L1b L2downloaded from ftp site 8 8free of errors 8 8Total L1b L2with corrupt bitmasks 14 0free of errors 9 17

Viewing opportunitiesPeriod 1.1. - 30.9.2003 273full coverage of Lake Constance 164- " - and FR data available 114- " - and good weather conditions 45


AcknowledgementAcknowledgement

Andreas Albert, DLR Roland Doerffer, GKSS Kerstin Ebert, DLR Thomas Heege, DLR Danielle Hoja, DLR Stefanie Holzwarth, DLR Harald Krawczyk, DLR Daniela Lipowski, Univ. Konstanz Sabine Miksa, DLR Till Lipowski, Univ. Konstanz Martin Mörtl, Univ. Konstanz Andreas Neumann, DLR Bringfried Pflug, DLR Kurt Sarembe, LfU Paul Schötz, DLR Alfred Sulger, Univ. Konstanz Sabine Thiemann, DLR Michael Weyhmüller, BBW Thomas Wolf, LfU

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Peter Gege and Stefan Plattner MERIS validation activities ... · Peter Gege and Stefan PlattnerPeter Gege and Stefan Plattner MERIS validation activities at Lake Constance MERIS