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INSPIRE Community Forum

How to deal with huge volume of coverage data - Case 1. Delivery through Predefined datasets: Revision

Source

Workshop "Implementation and potential of INSPIRE coverage data and WCS" - 30th September 2016 - INSPIRE Conference 2016, Barcelona.

Summary

This approach splits coverage data based on existing distribution units (e.g. like map sheets). These distribution units are then delivered using the same download services than INSPIRE vector data (ATOM or WFS). In such cases, the distribution units are equivalent to a specific tiling scheme.

This is not the most flexible way for delivering coverage data.

Any particular tiling scheme supports a particular purpose; in case of conflicting requirements (such as support of both spatial and temporal access of image timeseries) compromises have to be found. Best practices have been collected, e.g. by Paula Furtado in her PhD thesis (TU Munich, 2001).

Since handling raster data is costly (big data), the only way to achieve efficiency using such kind of services (i.e. ATOM or WFS) is splitting it in digestible pieces or tiles.

At the moment, this is the only option regulated in INSPIRE for delivering raster data, but the rules for delivering it through appropriate services (WCS) are close to be adopted.

In case of sticking to predefined datasets as a delivery option:

  • There is no need to set up guidelines on how to split the data (e.g. tile dimensions, maximum size for each tile).
  • Rather, each data provider should adjust its own parameters taking into account technical specifications: e.g. its server architecture, the weight of the data being delivered, the band width available for distribution to the user.

Conclusions

  • Use of predefined datasets is not the most flexible way for delivering coverage data.
  • To handle big coverage data, the only way to achieve efficiency using ATOM or WFS services is splitting it in digestible pieces or tiles.
  • Choice of tiling parameters is up to each data provider.
Elevation, Ortho & Grids

Elevation, Ortho & Grids

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