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Is it necessary to set up services for the Coordinate Reference Systems (RS) and the Geographical Grid Systems (GG) data themes?

Dear colleagues,

Regarding the Coordinate Reference Systems (RS) and Geographical Grid Systems (GG) themes,
I am looking for indisputable evidences about the NON-necessity of establishing all the services listed in the Directive 2007/2/EC, article 11, paragraph 1. At present I could mention: Technical Guidelines: - for RS, the data specification reads: “Contrary to the other themes the CRS specification does not concern a downloadable or viewable thematic data set.

Rather, it presents a basic functionality allowing the harmonised and interoperable geographic localisation of spatial objects defined by the other INSPIRE thematic data specifications.” (D2.8.I.1 Data Specification on Coordinate Reference Systems –Technical Guidelines, Executive Summary, Page VI). - Likewise for GG (D2.8.I.2 Data Specification on Geographical Grid Systems – Technical Guidelines, Executive Summary, Page VI). Implementing rules (n. 1089/2010): - In defining the spatial objects for the data sets listed in Annex I to Directive 2007/2/EC, they do not involve RS and GG.

In fact the data structure is not defined for these two themes, as they are not meant to provide data or services but to allow the harmonization of other themes. I kindly ask you to give me a reasoned opinion about this subject, and possibly to share your knowledge of any other documents that support this idea.

I would like your opinion also on another topic regarding Geographical Grid Systems: assuming that you confirm my theory that the establishment of services is not compulsory for this theme, I wonder if it would be convenient for a NMA (National Map Agency) to establish anyway a download service in order to facilitate the work of public and private data producers.

Do you think it could be useful or, quite the opposite, unsuitable?

Thank You

Massimo SPINELLI
ITALIAN MILITARY GEOGRAPHIC INSTITUTE
Florence

  • Peter BAUMANN

    By Peter BAUMANN

    Dear Massimo,

    cannot say much about the normative INSPIRE part, I'm not authoritative. However, being editor of the OGC/ISO coverage standards I am sort of competent technically.

    Re your last question, I'd be happy to discuss with you how OI services can be set up easily with the rasdaman OGC coverage reference implementation, but I would prefer doing this not via the list. If you feel this is of interest please contact me directly via baumann@rasdaman.com .

    best regards,

    Peter

     

     

  • Jordi ESCRIU

    Dear Massimo,

    It is probably difficult to get an official answer to your question.

    However, during the  29th Meeting of the INSPIRE MIG-T host in Ispra 19-20 April 2016 (link to agenda and presentations) I presented the PPT slides attached - "Question & Answer about CRS & GGS", related to your questions.

    The conclusion was that the INSPIRE RS and GG Technical Guidelines only establish requirements and recommendations related to the provision / organisation of INSPIRE data sets from other INSPIRE (data) themes. In other words, RS and GG themes govern the rules for providing, accessing and visualising data sets in the scope of INSPIRE, but they do not mandate the provision of themes-specific data themselves.

    Only in the case of GG it could be discussed the convenience of maintaining and providing INSPIRE datasets materialising the INSPIRE grids (e.g. as another reference datasets), but just as an option since there is no INSPIRE mandate.

    In my honest opinion, it could be useful to provide and describe national grids using such kind of datasets / services.

    A question from a Member State - "Is it was necessary to include in the INSPIRE Monitoring data corresponding to the RS and/or the GG themes?" - motivated this Q&A session during the mentioned MIG-T Meeting - Since there is neither mandate for provision of data for RS nor GG, there is no point to includes such themes in the INSPIRE Monitoring.

    I have also found one discussions topic (maybe I could find any other one) where these questions were also indirectly raised or mentioned, despite not being the central topic:

    https://inspire.ec.europa.eu/forum/discussion/view/97699/projections 

    Hope this helps.

    Jordi

  • Anja Loddenkemper

    By Anja Loddenkemper

    Dear Massimo, dear all,

    I have tried to start the discussion about grid systems in Germany in October 2017, but everybody seemed to agree to what I found out and so there simply was not discussion about it any more. Everybody read and kept silent...

    I had always thought about this fact you mentioned, (that there is no "truthful" INSPIRE for grid systems, why?).
     
    To let the tension grow to nothing...

    There is an OGC Specification telling anything you need about grid systems. It is called "The OpenGIS Abstract Specification, Topic6: Scheme for coverage geometry and functions", published 2006-01-30.

    You find the OGC specification here for download in a very huge list:
    https://www.opengeospatial.org/docs/as (publishing date 2007-12-28)

    Grid systems can be described with a mathematic function. So if you have this function you also have the grid system. The question to be answered is, how to create metadata showing this mathematical funcition. The metadata has to show what the grid system stands for and why it is there, anyway. But it also has to show the mathematical function itself.

    If I have data which are shown with the help of that kind of grid system I just use the mathematical function. I put my data into a WCS and use the mathematical function. My data is presented via WCS, but with the grid system as a basis for the layout of the data. That´s it. INSPIRE is all about the data. Not about the grid, not really. But the metadata for the grid systems in use is important. So there has to be a dataset-metadata for each grid used for presenting data of any kind.

    The specification by OGC is the same as ISO 19123.

    Grid system as an INSPIRE topic is due to the Technical Guidance "INSPIRE Generic Conceptual Model" (published 2014-04-08, https://inspire.ec.europa.eu/documents/inspire-generic-conceptual-model), page 10. There you have the reference to ISO 19123 which is identical to the OGC specification "The OpenGIS Abstract Specification, Topic6: Scheme for coverage geometry and functions", published 2006-01-30.

    In order to have it all in one place... here ist the Technical Guidance for "Geographical Grid Systems": https://inspire.ec.europa.eu/id/document/tg/gg

    I hope it helps, although I only made a rough translation of my email of 27th of October 2017 for GDI-DE AK Metadaten (Spatial Data Infrastructure Germany, working group on metadata) over here in Germany.

    Greetings from Hannover,
    Anja

  • Peter BAUMANN

    By Peter BAUMANN

    Hi all,

    just to add:

    - for CRS definitions, OGC operates a CRS resolver which is described at this wiki: http://external.opengeospatial.org/twiki_public/CRSdefinitionResolver/WebHome . It delivers the CRS definition for the usual EPSG suspects as well as further ones, like the OGC WMS Auto CRSs and time. Also, it allows to compose higher-dimensional CRSs from existing ones, such as for image timeseries datacubes.

    - Categories of grid types are established in the OGC Coverage Implementation Schema (CIS) 1.1, more fine-grain, structured, and comprehensive than the classical subdivision into RectifiedGridCoverage (regular grids) and ReferenceableGridCoverage (everything else).

    - In the process of establishing ISO 19123-1 as an abstract coverage concept and successor of outdated 19123 it was also agreed with the 19111 folks that grids would be described in that 19123-1.

    -Peter

     

  • Jordi ESCRIU

    Dear Massimo,

    Let us know if you resolved your questions / doubts or you need extra information / input.

    If not I will proceed to close this discussion topic.

    All the best

    Jordi

  • Massimo Spinelli

    By Massimo Spinelli

    Dear All,

    Sorry for my delay

    Sure, my doubts have been resolved and I would like to thank everyone.

    Best regards

    Massimo

  • Jordi ESCRIU

    Thank you to you, Massimo!

    As a result, I proceed to close this topic.

    All the best.

This discussion is closed.

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Elevation, Ortho & Grids

Elevation, Ortho & Grids

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