introduction into the window channels
DESCRIPTION
Introduction into the Window Channels. Description of characteristics and content of the channels: Ch07: 8.7 Ch09: 10.8 Ch10: 12.0 . Contact person: Veronika Zwatz-Meise [email protected] Version 1.0. 13 July 2004. All MSG channels. Channel 01:VIS 0.6 - PowerPoint PPT PresentationTRANSCRIPT
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Introduction into the Window Channels
Description of characteristics and content of the channels:
Ch07: 8.7 Ch09: 10.8 Ch10: 12.0
Contact person:Veronika [email protected] 1.0. 13 July 2004
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All MSG channels• Channel 01: VIS 0.6 • Channel 02: VIS 0.8 • Channel 03: NIR 1.6 • Channel 04: MIR 3.9 • Channel 05 WV 6.2 • Channel 06: WV 7.3 • Channel 07: IR 8.7 • Channel 08: IR 9.7 („Ozon“)• Channel 09: IR 10.8 • Channel 10: IR 12.0 • Channel 11: IR 13.4 („CO2“)• Chanell 12: HRV (High Resolution Visible)
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Sun radiation Earth radiation
Ch07: 8.7 Ch09: 10.8 Ch10: 12.0
Wavelength (micron)
Watt/m2 andmicron
Ozone
Carbondioxid
Watervapour
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Comparison of radiation sources sun - earth
• For wave length < 5 m solar radiation is dominant • For wave length > 5 m radiation of earth is dominant
only VIS
VIS +IR
only IR
• Ch01, 02, 03, 12: only sun radiation • Ch04: both: radiation from sun and earth • Ch 05, 06, 07, 08, 09, 10, 11: only thermal earth radiation
Sun radiation Earth radiationWatt/m2
andmicron
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• Ch07, 09, 10 in window region• Therefore: no fundamental attenuation of the radiation through absorption
EnergyspectrumSource:EUMETSAT
Ch07 Ch09 Ch10
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Figure 3c
Max. signal in the window channels from the surface and lower part of troposphereWeighting
functionsSource:EUMETSAT
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Application areas for the window channels
• Recognition of cloud systems because of the thermal radiation of cloud and earth surface
• Extraction of high thin Cirrus from the whole cloud systems
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Ch07: 8.7
9
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Some characteristica: Ch07: 8.7
• Indicative for high, thin Cirrus cloud– improved recognition of Cirrus– best use through preparation of
RGBs and differences
• Support for discrimination between ice- and water cloud
• From optical point of view (at the time being) no typical new features recognisable
11Ch07:8.7
12Ch09:10.8
13Ch10:12.0
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Ch09: 10.8 and Ch10: 12.0
These channels are comparable to the relevant NOAA channels
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Sun radiation Earth radiation
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Some characteristica: Ch09: 10.8 and Ch10: 12.0
• Usual evaluation of cloud in both channels
• Not much difference between the apperance in the three window channels
• Ch10 is more sensitive for high thin Cirrus– not easy to recognise
through checking by eyes– difference images give
information
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Ch07: 8.7
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Ch09: 10.8
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Ch10: 12.0
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Split window Ch09: 10.8 and Ch10: 12.0
• Ch10 is more sensitive for high thin Cirrus– not easy to recognise
through checking by eyes– difference images give
information
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Absorption of Ice- and Water cloudAfter Source:D. Rosenfeld
Different Absorption of Ice- and Watercloud between 10.8 and 12.0 m
Higher absorption in the ice phase in 12.0
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Examples for visualisation of high Cirrus
Differencen of I07, I09, I10
Source:Jochen [email protected]
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DifferenceI07 - I09Angola
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DifferenceI09 - I10Angola
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DifferenceI07 - I09S-Atlantic
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DifferenceI09 - I10S-Atlantic