INSPIRE Thematic Clusters

Example data in accordance with OI application schema (for Copernicus guidelines)

868 Views

Dear OI experts,

we have recently been asked for feedback on a draft technical note on "INSPIRE Metadata Tailoring Guidelines for Copernicus Contributing Missions (CCMs)" currently being developed by ESA.

During the discussions, the question arose how to provide the additional metadata defined in the Orthoimagery application schema (i.e. domain extent, interpolation type, footprint, name, phenomenonTime, beginLifespanVersion and endLifespanVersion) and how to provide the image itself.

The encoding section mainly refers to the encoding based on the GML coverage schema, but does not give any specific examples for how to use these for OI data. Also, it is unclear if coverages are the only (recommended) way to provide the additional OI metadata elements, or if they could also be provided in some other way together with an image file.

Has this been discussed in the TWG OI when developing the data specification, in particular for the case of satellite imagery?

Are you aware of any examples of OI data that have already been provided in compliance with the INSPIRE OI application schema?

Thanks & best regards, Michael

Replies

    • Public

    By Peter STROBL

    Can't answer the metadata part of your question, but when it comes to the delivery of the imagery we recently discussed this here at several instances. The status, as far as I understand it, is the following:

    The ETRS89-LAEA projection used so far as the pan-European standard in all COPERNICUS procured OI (mostly through ESA) would under INSPIRE only allow cell sizes which are powers of 10, which was confirmed in this thread. Accordingly almost all COPERNICUS OI data are NOT INSPIRE compliant.

    I personally doubt that the proposed "zoned geoographic grid" is a viable alternative, at least no one yet delivered a use case, see related the related discussion.
     

    So, for now there is no solution! Given the current rapid developments in Earth Observation, I find this quite worrying.

    • Public

    By Michael LUTZ

    Feedback received from Pierre-Yves Curtinot (IGN France, editor TG OI):

    Dear Michael,

    As with other themes, OI data delivery is based on GML encoding. The way of structuring and completing the content of the resulting GML document is specified in the Orthoimagery GML Application Schema provided by INSPIRE (http://inspire.ec.europa.eu/schemas/oi/3.0/Orthoimagery.xsd). This xsd file includes all the elements of the Orthoimagery  Application schema described in the section 5.3 of the OI DS, since it derives from it. It means that the resulting GML document contains a description of these elements and in particular, of what you call additional metadata (i.e. domain extent, footprint, name). It also gives the characteristics of coverages, which is essential.

    For obvious reasons of efficiency, it is most often preferable to store the range set of the coverage (i.e. pixel values) outside the GML document. In this case, the GML document can point to the associated image files through URIs. Of course, image files may contain descriptive information, additional or not. But it is required to be consistent with the GML part.

    Then the question is how to package GML representation and image files together. The different options are presented in the section 9.4 of the OI DS: multipart representation, reference to an external file, encoding the range inline, GMLJP2.

    If it can help, you’ll find attached a dataset that I produced for the testing of DS in 2010, and that I updated since. I just replaced tif files by text files to be able to send them by email.

    Note that I have been also contacted by the company Airbus Defence and Space who is designing a new INSPIRE-compliant product based on satellite imagery. If you are interested, I can send their contact details to you so you can share your experience.

    Best regards,   Pierre-Yves Curtinot

    Attached example OI dataset:OI example data set

    • Public

    By Julián DELGADO

    Dear Michael, Pierre-Yves

    Many thanks for the provided example. I have worked during last weeks in the application of coverages for Spanish OI datasets (PNOA); and reached a result quite similar than your example. I feel very pleasent that I worked in the correct way.

    What tool did you use to reproduce the example? I used FME and works good, even to carry out a simple validation of the XML structure against INSPIRE XSDs. My idea is to share my work after I document it.

    I attach the file, and some picts too.

    https://themes.jrc.ec.europa.eu/file/view/24123/example-of-spanish-oi-dataset-into-inspire-pnoa
    https://themes.jrc.ec.europa.eu/file/view/24125/oi-example-generation-with-fme
    https://themes.jrc.ec.europa.eu/file/view/24129/oi-result-in-fme
    https://themes.jrc.ec.europa.eu/file/view/24142/oi-result-in-qgis

    My best regards

     

    • Public

    By Jordi ESCRIU

    Since the examples provided seems to cover appropriately the initial requets from Michael, I proceed to close this discussion topic.

    Jordi

This discussion is closed.

This discussion is closed and is not accepting new comments.

Elevation, Orthoimagery, Reference Systems and Geographical Grids Cluster

Elevation, Orthoimagery, Reference Systems and Geographical Grids Cluster

INSPIRE Thematic Cluster Elevation, Orthoimagery, Reference systems, Geographical grids - Join this group to share your knowkledge, learn and collaborate in solving issues related to the Elevation, Orthoimagery, Reference systems and Geographical grids themes