1. HMA-FO Task 1 EOP Metadata
Darmstadt September 2009
Frédéric Houbie, ERDAS

2. Agenda Introduction to HMA-FO Task 1 objectives
Improving the current specifications using MDA, O&M, … Output of HMA-T : management of VGT products
Presentation from STFC
Presentation from EUMETSAT/CNES/CLS
Presentation from GECA (given by S. Smolders)
OGC CR to fulfill the HMA-FO requirements
Slide 2

3. Structure Consortium structure Proposed Work Plan Proposed Schedule
EO Product Metadata Structure
Proposed Extensions
Proposed approach
OGC Process
Validation of the approach
Proposed Schedule
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4. Consortium structure Consortium leader OGC Standardisation process
Test suite
New schemas for systematic & synthesis products
Implementation in HMA Skeleteon & SSE client
New schemas for radar altimeter & limb looking products
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5. Proposed work plan WP1000 Project Management
WP2000 Analysis of the extensions and update of EO GML
T2100 Document Update & OGC Process
T2200 Synthesis and Systematic products
T2300 Radar altimeter, limb looking products & new schemas
WP3000 Tests
T3100 SSE
T3200 CITE
WP 4000 OGC Process
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6. Current EO Product Metadata stack
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7. Proposed extensions Radar Altimeter Limb-looking products
Systematic and Synthesis Products
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8. Radar Altimeter
No particular problem to handle this new model in the current EOP basic structure tree
In principle, the altimeter's operation is straightforward (Figure 3): timed radar pulses are used to measure the distance, h, between the satellite platform and the instantaneous sea surface. With knowledge both of the satellite’s orbit relative to the earth's reference ellipsoid, O, and the geoid, N, the sea-surface height (SSH) relative to the geoid is then known:  = O-N-h
To be useful, the SSH should be determined to O(cm) accuracy, placing severe requirements on geoid knowledge, the altimetric radar, and knowledge of the satellite’s orbit.
To achieve sufficient altimeter accuracy, several corrections must be made to the measured SSH. Delays in the altimeter signal are caused both by tropospheric water vapour and ionospheric free-electron content, both of which vary in space and time and must be corrected for. The radar pulse transmitted from the altimeter has a “footprint” diameter of several kilometres. Over this area, the reflected signal is affected by the sea-state: maximum energy in the return pulse generally does not correspond to reflection from the mean sea-surface. These so-called electromagnetic bias effects contribute significant errors that are difficult to correct. Local atmospheric pressure loading on the ocean produces changes in sea-level of the order of one cm per millibar. This “inverse barometer” effect must be compensated accordingly. Finally, the ocean's tides are generally ignored for oceanographic problems, so must be modelled and removed from the measured SSH signal.
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9. Limb looking products
Limb viewing instruments view the limb of the atmosphere – this could be sideways-viewing, backwards-viewing or a combination.
Issue : geolocation information, currently extend is limited by schematron rule and only in WGS84
Will have to extend the geometry information to 3D and other CRS
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10. Systematic and Synthesis Products
Combined EO products (ex VGT started in HMA-T2)
Already a set of comments in the OGC SWG
Extension of CompositeType
Improvement of processingInformation
Linking between EO Products to be analyzed and improved
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11. Proposed approach
Objective = describing and cataloguing the new products
Analyze the data
Extract important metadata
Create new product type metadata and/or extend existing levels (using new methods like MDA, O&M, ...)
Extend/Improve the current EO EP to facilitate storage and discovery of metadata
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12. OGC Process
Continue the current process of standardisation of EO GML and its cataloguing model, EO EP
Important to bring domain people in the discussion (was lacking in HMA-T).
 Open a Public OGC Wiki for EO GML & EP discussion (like in METEO DWG), without OGC membership required. Of course only OGC members will vote.
Obtain quickly a draft updated document (KO + 8 at the latest) to allow validation by CITE and SSE that it fulfills the requirements, then start the standardisation process of vote with the argument that it is implemented and functional.
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13. Validation of the approach
SSE / HMA-Skeleton
New request/response to validate
Integration in SSE workflow
CITE tests
Update of existing CITE scripts
Creation of new ones for new products type
Update existing schematron files
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14. Project Schedule
Slide 14