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ECV Inventory – Overview and Background

Around 2009 “a certain gentlemen” challenged CEOS to describe how CEOS was actually contributing to the generation of the GCOS ECVs

This triggered a background investigation into what “contributing to a GCOS ECV” actually means

Inspiration was mainly drawn from the GCOS Satellite Supplement, the GCOS Climate Monitoring Principles and the GCOS Guidelines

The full set of GCOS requirements were then filtered and those with functional implications were then represented within a Logical View

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ECV Inventory – Logical View

Logical View is easier to explain/sell than plain text

Logical View is generic – i.e. the processing steps are applicable to all ECVs……e.g.:

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ECV Inventory – Limitations of the Logical View

Although the Logical View is very useful for explaining the big picture, it has limitations, e.g.:

o Does not give visibility of the part of the GCOS requirements baseline that is ECV-specific and generally non-functional in nature (e.g. ECV-specific requirements on accuracy, frequency, coverage, stability, etc)

o Does not give visibility on the part of the GCOS requirements baseline that is generic (i.e. common across all ECVs) but not functional in nature – e.g. provision of documentation on algorithms used….

So another View was needed which could capture all aspects of the GCOS Requirements baseline, as well as provide a means of overlaying the various space agency contributions

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ECV Inventory – Need for Another View

So a “Physical View” was constructed to complement the “Logical View” and became known as the “ECV Inventory”

This ECV Inventory was designed from the outset to fulfil a number of objectives, including:

o Represent the full scope of the GCOS Requirements baseline (including the Functional View)

o Act as a repository for representing the current ECV-relevant data-holdings of agencies in a manner that exposes their degree of compliance with the relevant GCOS requirements

o Act as a repository for representing the planned ECV-relevant data holdings of agencies

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ECV Inventory – Structure and Questionnaire

Structure of ECV Inventory – 2 components:

o Current component (sections: general, dataset usage, dataset stewardship, dataset properties, dataset access…)

o Future Planning component (similar section structure as current component but reduced in scope)

Questionnaires released to agencies in 2012 for the population of the ECV Inventory – these questionnaires were designed so as to ensure that every aspect of the ECV inventory is addressed

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ECV Inventory – Structure of the Questionnaire

o General (e.g.: contact details, dataset identifier, responsible organisation, .....)

o Dataset Usage (anticipated climate applications, ECV that can be generated from the dataset)

o Dataset Stewardship (implementation arrangements for each of the functions identified in the logical architecture)

o Dataset Properties (e.g. start and end-date of the record, until when are commitments in place for continuation of the record, physical quantity the dataset measures, units, sensor, geographical coverage, resolution, accuracy, stability, scientific review, generation process, assessment of stability and homogeneity, peer review, maturity index….)

o Dataset Access (contact details for getting access, format, access conditions, dissemination, documentation ...)

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ECV Inventory - Sample Extracts of the Questionnaire

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ECV Inventory - Sample Extracts of the Questionnaire

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ECV Inventory - Sample Extracts of the Questionnaire

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ECV Inventory - Sample Extracts of the Questionnaire

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ECV Inventory - Summary

Logical View- a very useful entry point - generic (common to all ECVs) and describes in a readily accessible format the main processing steps

But……it does not give the full picture as it is not a suitable format for capturing non-functional and ECV-specific requirements (e.g. accuracy, stability, coverage, documentation needs, etc)

In contrast to the Logical View, the ECV Inventory contains the complete picture (i.e. the full GCOS requirements versus their current and planned implementation status) at the level of individual ECVs but, unlike the logical architecture, is not succinct

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ECV Inventory - Summary Ctd

The ECV Inventory is the essential component/mechanism for the fulfilment of the three main objectives assigned to this Working Group

Looking to the future – if the structure of the GCOS requirements baseline changes (e.g. introduction of application-specific requirements within ECVs) then this may have a direct impact on the ECV Inventory