WGCV Report and Actions Pascal Lecomte – Chair Greg Stensaas – Vice chair Marie-Claire Greening - Secretariat 1 23 rd CEOS Plenary I Phuket, Thailand I 3-5 November 2009

2009 Accomplishments DA-09-01a_6: Ground-based Cal/Val Campaign – Miami – Tuz Golu (2009) DA-09-01a_7: DOME C Experiment DA-09-01a_8: Cal/Val & Post-launch Test Sites (Reference Standards) DA-09-01a_9: Radiometric Standards: Standards for post-launch cal/val have been established DA-09-01a_10: QA4EO CINDI rd CEOS Plenary I Phuket, Thailand I 3-5 November 20092

Current and Future Challenges DA-09-01a_11: Reference Test Site Data Collaboration & Comparison – consolidation & expansion DA-09-01b_1: Land Product Harmonisation – continuation & reporting DA-09-03d_3: Global DEM – continuation DA-09-03d_4: Global DEM – on standby 23 rd CEOS Plenary I Phuket, Thailand I 3-5 November 20093

Requested Commitments DA-09-01a_5: Benchmark Mission Coordination: CLARREO is progressing well (NASA support + dialogue formalised with UK) That task remains opened due to the lack of support from the CEOS Agencies.

Further WGCV Objectives DA-09-01a_6: Ground-based Cal/Val Campaign – Tuz Golu (2010) & possible activities related to Ocean colour (working with the OC constellation) DA-09-01a_7: DOME C Experiment: Extend that task for calibrating microwave instruments at Dome C.

Further WGCV Objectives DA-09-01a_10: QA4EO: – establish a high-level task teams with representatives from all societal benefit areas (SBAs) – A one-page summary describing the key principle of QA4EO – A High-level implementation and action plan will be drafted – A ‘communication toolbox’ – presentations, posters, brochures, etc.

Recommendation 1 from WGCV CEOS has an already-established and endorsed set of global reference sites that provide appropriate and well-characterised reference targets for Cal/Val purposes. In order to enhance sensor Cal/Val and also to allow cross-comparison, the WGCV recommends that CEOS members incorporate regular acquisition over all CEOS endorsed reference standard sites into appropriate sensor acquisition programmes. The resultant datasets should be made available through the CEOS Cal/Val portal. In particular, acquisitions should be timed to match key ground comparisons, e.g. Tuz Gölü August 2010.

Recommendation 2 from WGCV The WGCV recommends that CEOS members endorse Aeronet-OC and Lake Tahoe as CEOS reference standards and their use be encouraged (see 1 above).

Recommendation 3 from WGCV The WGCV recommends planning for an OC surface sites pilot comparison, followed by a CEOS comparison in the timescale of 2011.

Recommendation 4 from WGCV The WGCV actively promotes and encourages intercomparison campaigns to enhance both ground-based and / or satellite sensors. In 2009 successful intercomparison activities were undertaken over the snow fields around DOME C (Antarctica), off the coastal waters in Miami and in the salt lake of Tuz Gölü. Participation from all relevant parties is very much encouraged and the WGCV strongly recommends that CEOS members actively support participation in the CEOS comparison of land surface reflectance in August 2010.

Recommendation 5 from WGCV The WGCV recommends that CEOS members support the continuity and expansion of product validation activities to allow for the quantification of associated uncertainties and to allow fusion between similar products. This includes: – The provision of easy and free access to high spatial resolution imagery (Landsat / Spot class). – The support for ground measurement activities. – The support for the development of the OLIVE (On Line Interactive Validation Exercise) web interface system on the Cal/Val portal for sustainable, transparent and independent validation exercises.

The WGCV and WGISS welcomes the substantial progress made in recent years towards the provision of a global 30m Digital Elevation Model (DEM), although there are still deficiencies in coverage and in validation data. The WGCV and WGISS also recognise the importance of DEMs for GEO societal benefit areas and downstream EO data services. Therefore, it is recommended that CEOS member agencies agree to co-operate in the completion of a complete, gap- free and validated DEM by an agreed goal of June 2010 and no later than June This global DEM should include heights at 30m spacing over land based primarily on existing proven GDEMs, such as that based on data from the ASTER sensor, and for bathymetry down to depths of m on continental shelves, including the production of a much more accurate coastline especially in the Arctic region. Recommendation 6 from WGCV

The WGCV and WGISS recommend that the following CEOS members investigate the setting-up of an OGC-compliant WMS server for colourised hill-shaded DEMs to be employed for the assessment of the potential of their DEM datasets to be used to help to create the GEO Global DEM through the agreed ICEDS web-GIS: – JAXA for ALOS-PRISM and ALOS-PALSAR – DLR for SRTM-X – SPOT Image for Reference 3D – ISRO for Cartosat – NASA for ICESAT-GLAS – ESA for RA and ACE – USGS for GTOPO30v2 Recommendation 7 from WGCV

High resolution satellites are becoming surveying instruments. This poses strong requirements on orbit knowledge and maintenance, particularly for SAR systems: Absolute orbit knowledge is needed well beyond the SAR resolution cell size; better at wavelength accuracy Relative orbit knowledge is needed at sub-wavelength accuracy Controlled orbital spread is required for advanced applications such as polarimetry and interferometry Under-sampled image products cause a performance loss in the impulse response function (IRF) impacting resolution. The WGCV therefore recommends that CEOS members only deliver products that are appropriately sampled, even at the expense of an increased product file size. Recommendation 8 from WGCV