Thank you, Martin. I don't work full-time in GIS (I spend about a week thinking about GIS every two years) and resources like this are very useful to keep me up to date. Please keep them coming!
In other news. I finally merged two Geospatial features into Calcite's master branch [1] [2]. These make it possible to add efficient Geospatial indexing in a DB that does not have specialized Geospatial data structures; regular b-tree indexes or sorted tables are sufficient. I'm sure these approaches are well below a specialized GIS system in terms of performance, but allow you to build a hybrid system that does other things (e.g. streaming, documents, XML, analytics) well also. Julian [1] https://issues.apache.org/jira/browse/CALCITE-1861 [2] https://issues.apache.org/jira/browse/CALCITE-2160 On Wed, Sep 23, 2020 at 1:34 PM Martin Desruisseaux <[email protected]> wrote: > > Hello all > > Last week, an Open Geospatial Consortium (OGC) virtual meeting was hold. > During that meeting, we got a link to a video about dynamic Coordinate > Reference Systems (CRS). This video explains issues to be aware for > anyone who wants to locate a point on Earth with a precision better than > 3 meters. In particular the use of WGS84 is not sufficient for such > precision, unless coordinate values are completed by an epoch. > > https://youtu.be/IKM-bR6SwVs > > This video is produced by IOGP (International Association of Oil & Gas > Producers). IOGP is the creator and maintainer of the EPSG geodetic > dataset, which provides Coordinate Reference System definitions used by > about all GIS (Geographic Information Systems) to my knowledge. The > presenter is Roger Lott, who has been the editor of ISO 19111 > (referencing by coordinates) latest revision, of ISO 19162 (Well Known > Text 2) standard and is currently leading the standardization of a file > format for datum shift grids deformation models and more. The recent > advances in OGC/ISO international standards on referencing by > coordinates owe him a lot. > > More details on the topic discussed in the video can be found there: > > > https://www.iogp.org/bookstore/product/geomatics-guidance-note-25-dynamic-versus-static-crss-and-use-of-the-itrf/ > > Martin > >
