1. EO CalVal Portal Philippe Goryl ESA/ESRIN
INTER-COMPARISON DATA, PROTOCOLS & GUIDE LINES
FOR CAL &VAL

2. CEOS WGCV Recommendation
Cal/Val portal is the ESA response to the CEOS recommendation
Initiate an activity
document reference methodology
to predict Top of Atmosphere (TOA) radiance
for intercomparison of currently flying and planned wide swath sensors
create a standard for traceability
Create and maintain a fully accessible web page
instrument characteristics
database of instrument data
specific vicarious calibration sites
common format
CEOS Working Group on Calibration and Validation, 18th Plenary Meeting, Beijing, November 2004, Doc No: 12.1

3. EO CALVAL Portal Harmonisation & Interoperability Requirements
Instrument characteristics
(Radiometry, Spectral
resolution, Geometry)
Reference Methods and protocols
(Cal./Val. Techniques)
Data
Calibration Metrics (sensor data)
Diagnostic sites
WTF sites
Ancillary information networks
e.g. AERONET
Database
Database
GECA
Harmonisation & Interoperability Requirements
Other Agencies
Instrument data
Catalogue and data access
methodology

4. Project Elements Web Portal
Description of methodologies (IVOS for the 1st release)
Description of instrument characteristics (SensorML)
All GMES sensors will be supported (optical, radar, atm.Chem.)
Access to EO data
Designed to support all GMES sensors
Version 1: MERIS FR and RR, AATSR, ALOS PRISM and AVNIR2
Version 2: additional Chris/Proba, Vegetation, …
Access to in-situ data
Local database
Access to Nilu, Aeronet, external database (GECA)
Access to tools
CalVal Results
User management, Forum, Help

5. Plan for 2007 WTF continuation
AATSR: full archive reprocessing and rolling archive metric (MERIS calibration site) extraction
Integration and extension to other IVOS
Integration of geometry validation – methodology, GCP, reference data
Proposed standardisation for the geometric validation
Evolution to non optical sensors – SMOS / SAR
Strengthen the link with validation DB
Access to other catalogues/dataset (international cooperation)
Fill the cal/val portal with documentation/project.
Automatise cal/val procedures (reciprocity method over Bolivian site)

6. Plan for 2007 WTF Continuation
Target
A major effort stated in the extension contract of the CalValPortal shall focus on the seamless continuation of the data services provided by USGS covering sensor calibration datasets. This project is known as the WGISS Test Facility (WTF core test sites). The service shall be integrated into the CalValPortal web-interface software.
To reduce duplication of data and to ensure that continuous updating of the content can be performed by the US partners, the datasets shall reside at their original location. A set of appropriate metadata shall be extracted from the existing archive datasets. This metadata shall be integrated into the CalValPortal database system to allow standard queries through the web-interface and streaming download of selected result products.
The calibration sites stored at USGS shall be integrated into the CalValPortal as regular sites, eventually identified by a site group identifier.

7. Plan for 2007 WTF Continuation
Suggested solution
Establish communication To ensure close collaboration with the USGS technical staff, communication channels shall be established.
Analyse existing datasets A thorough inventory of the content of the current WTF web system shall be performed. This study shall identify all data servers attached to the USGS system in terms of Accessibility (current set-up, possibilities to adapt access methods)
Data content
Static or dynamically growing source
Define of common metadata A set of metadata shall be defined that allows the integration of the continuation service into the CalValPortal system. Requirements for this task are:
A simple format
Metadata fields are contained in the source products
Metadata covers sufficient information to allow integration into CalValPortal system.

8. Plan for 2007 WTF Continuation
Suggested solution
Generate metadata
Once the metadata format and the image properties are defined, the WTF server
content needs to be processed to generate metadata and image files. The results
of this stage needs to be transferred to BC.
Integrate into CalValPortal
The software and database schemata of the current CalValPortal system need
to be updated to be able to handle injection of metadata files, automated storage
of quicklook images and the retrieval of remote datasets.
Metadata and image files resulting from 2.4 must be ingested into the CalValPortal
system.
Continuous updates
Methods need to be defined to ensure that the WTF server data content is
mirrored correctly in the CalValPortal. A change in server content can result from
New data being ingested
Obsolete data being removed
Reprocessing of data requires updates

9. Plan for 2007 WTF Continuation
Current status
Contact to has been successfully established. Primary contact persons are:
John L. Dwyer at SAIC, Contractor to the USGS Center for Earth Resources Observation and Science, Jeffrey Morisette at NASA's Goddard Space Flight Center, Terrestrial Information Systems Branch
A thorough analysis of existing datasets server content has been performed and the result has been distributed to the partners. The WTF data content has be analyzed according to the following criteria
Number of datasets per product type/sensor
Availability of metadata
Availability of quicklook images
Web-address and access mode of the servers
Software “spikes” to validate the feasibility of the solution planned have been implemented and successfully tested.
A metadata format has been defined by Brockmann Consult that covers all the needs expressed. This format has been proposed to the partners at USGS/DAAC and has been accepted in general. A detailed analysis is currently taking place.

10. Plan for 2007 WTF Continuation
Current status
Partners at USGS are analysing the efforts needed to generate the metadata and quicklook images. For most of the data stored at WTF, metadata does not exist and has to be generated from the satellite products. Software needs to be written to realise this target. It has been agreed that USGS partners re-use existing software with the capability of reading all data formats to generate metadata.
Metadata and quicklook images should be prepared and be made available for download in a suitable way, which needs to be discussed.
A major obstacle seems to be that USGS has not enough human resources at their disposal to realise the metadata generation task.
Actions
John Dwyer is currently discussing wit the USGS/DAAC technical staff about possibilities to generate metadata and quicklook-images. This discussion shall result in a rough estimate on the manpower needed for realisation.
A tele-conference is been planned after WGISS meeting to iterate further steps.

11. Calibration Support The CalVal Portal will support calibration by
Supplying Satellite Data from multiple Sensors
Supplying in-situ Measurements
Supply Sensor Parameters
Prepare input files for 6S given Sensor Parameters, Atmospheric Conditions, …
Supply a platform to exchange results
Give access to calibration tools
BEAM
6S input file generation
6S RTT …

13. User Navigation Guidance

14. Access to Satellite Data
Daily extraction and registration
MERIS RR L1/2
AATSR
over all sites
- ALOS AVNIR/PRISM
Over selected sites

15. Product Detailed Page

16. Methodology Reference methodology for optical sensors
Vicarious calibration: a reflectance based method
Applicable to
Visible
NIR
Available as a document for download from the Portal
Scientific background
General approach
Cook-book like step-by-step description
Supported by interactive tools and links to SW tools
Future extension: Reference methodologies for
Geometry
Radar instruments
Atmospheric chemistry

17. IVOS Methodology NB : Methodology will be extended from radiometric
Only to Geometric calibration

18. Structure of the Method Description
Introduction, Applicability, Scope
Physical / mathematical description
Technical Description
Overview
Detailed description of Modules
Preparation, Campaign planning
EO data retrieval
EO data extraction
Meteorological data
Aerosol model
Surface reflectance (in-situ data)
Radiative transfer model
Calibration
Application Example (La Crau)
Recommendations of in-situ measurements
Numerical models 6S
SOS code

19. Methodological Reference
PDF/html with scientific background description
PDF/html with application examples (Cook-book)

20. Methodological Reference
html/PDF with scientific background description
html/PDF with application examples (Cook-book) ready
Vicarious calibration in the solar domain using bright land test sites - Methodology
Vicarious calibration in the solar domain using bright land test sites: The La Crau site
Detailed description of current technology
The Acqua Alta Oceanographic Platform (AAOT) Site (Zibordi & Berthon)
The SeaPRISM CIMEL radiometer (Zibordi, Berton & Melin)
Measurements for calibration in the solar domain: The automatic CIMEL radiometer (R. Santer)
RTC for calibration in the solar domain; the Successive Order of Scattering code (R. Santer)
Second Simulation of a Satellite Signal in the Solar Spectrum (Eric Vermote)

21. IVOS Methodology Support

22. IVOS Methodology Support 2

23. Example: use of the cal/val portal for: Cross calibration: ALOS and MERIS over land
MERIS: a reference!
Strong requirements for ocean colour
On board calibration
Clear sky conditions
Two types of sensors:
Spatial resolution=> homogeneous site
Spectral features
ALOS and MERIS extracted over the same stable sites available in the cal/val portal

24. The AVNIR2 spectral bands
MERIS
AVNIR2 spectral bands and the atmospheric transmission for an aerosol free, mid latitude summer atmosphere with WV=2 g.m-2 and O3=300 Dobson
Both MERIS and ALOS precise spectral response are given in the Cal/Val portal

25. Spectral match: Methodology
Derive surface reflectances from MERIS
6S backward
Atmospheric model
Aerosol model
Reconstruct the surface reflectance for ALOS
Introduicing a mean reflectance for each band
BRDF model
Derive TOA ALOS reflectances
6S forward with the same conditions
The ALOS official solar irradiances
6S and pre-processing tool is given in the cal/val portal.
Solar irradiance used in ALOS is given in the cal/val portal.
Angles calculation for ALOS is given in the cal/val portal.

26. Second order terms BRDF correction Aerosol model
Using BRDF model of the site (POLDER-PARASOL)
Aerosol model
Proximity of AERONET station
(access via Cal/Val portal)

27. Results: Intercalibration ALOS AVNIR calibration verification
B1:0.954 B2: B3:0.927 B4:0.829 when accounted for WV, B4 0.876

28. Summary
EO CalValPortal provides data, instrument description and methodologies for Calibration and Validation
Version 1 supports calibration of IVOS sensors
Version 2 (2007)
extension to geometric calibration
validation support
extension to other types of sensors
incorporation of the functionality of the CEOS WGISS Testfacility
CalVal projects can link into share data and results
Globcolour, MAVT/MQWG, ALOS are currently using the portal
Work in accordance with and supported by CEOS
GEOSS is interested in taking on board the CalVal Portal