swot and user needs workshop, dlr oberpfaffenhofen, 5-6 july 2006 hyressa - hyperspectral remote...
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SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Data Processing
Eduardo de Miguel
Remote Sensing Laboratory
INTA - Spain
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Introduction
• Data processing = Data calibration + quality control + data transformation + information retrieval
• Both at user side and provider side
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Data Processing
• Usual DP tasks at provider side:– Radiometric calibration – Geometric correction– Atmospheric correction (might be included in
radiometric correction)– Evaluating product accuracy (quality control)
• Unusual DP tasks at provider side:– Data transformations (PCA, MNF, spectral
resampling…)
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Data Processing
• Usual DP tasks at user side:– Data transformations– Endmember selection – Spectral unmixing, spectral matching...– Classification– Feature detection– Running models– …
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Standard tools
– Radiometric calibration: linear models– Geometric correction: direct geo-referencing– Atmospheric correction: MODTRAN and
relatives (ATCOR, ACORN, FLAASH), ATREM, vicarious calibration (empirical line)
– Temperature/emissivity separation: TES, others??
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Standard tools
– Spectral tools: …– Transforms: … – Classification: …– Filters and convolutions: …
(See ENVI as show-case of standard tools)
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Standard tools
– Quality control & accuracy measures: ??– Metadata definition: none (ISO19115??)– Metadata documentation/distribution: none– Data inventory/catalogues: none
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
SWOT
• Strengths and Weakness (I)– Geo-registration procedures satisfactory. (It is
re-sampling correctly addressed?)– Radiometric/atmospheric correction is often
close to 5% error in reflectance units.– Reporting geometric accuracy is not clear.– Reporting radiometric accuracy requires
ground spectra / temperature.
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
SWOT
• Strengths and Weakness (II)– BRDF effects (and emission angular effects)
are still outside of the standard processing pipeline.
– Temperature/Emissivity algorithms far from being operational.
– Metadata are not provided in a regular basis nor in a standard way
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Developments
• A review of DP topics in the 2004 EARSel SIG IS workshop and the 2006 IGARSS.– Endmember extraction, spectral unmixing,
advanced classification procedures…– BRDF modelling– Compression– Others– Nothing on quality/accuracy measures and
metadata
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Discussion Points
• It is geometric resampling a problem?• How to evaluate the geometric accuracy?• Which is the way to reduce the 5% error in
atmospheric correction? • Should the spectral unmixing be performed at
the provider side? (it is affected by instrument features, like PSF and spatial sampling)
SWOT and User Needs Workshop, DLR Oberpfaffenhofen, 5-6 July 2006
HYRESSA - HYperspectral REmote Sensing in Europe specific Support Actions
Discussion Points
• It is worth to put effort on data compression?• When will be BRDF correction a common
practice?• What is the users feeling about metadata?• …• (Your entry here)