6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 1 A Spatial Reference System (by co-ordinates) for Europe

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 2 topics  Reference systems : a reminder  Transformation and conversion  Spatial Reference System Workshop : a 1999 SAI/MEGRIN initiative  Spatial Reference System for Europe : recommendations

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 3 ? egg or grapefruit ? do we live on the same planet?? ….why different spatial reference systems?

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 4 geo-referencing by co-ordinates geo-referencing by co-ordinates

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 5 geodetic datum geodetic datum Z X Y

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 6 map coordinates E N

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 7 ellipsoïd to plan h  E N

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 8 heights geoid earth surface ellipsoid h N H

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 9 change of system Datum 1 N, E, (h) X, Y, Z,  (h) N, E, (h) X, Y, Z,  (h) Datum 2 transformation conversion

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 10 why different systems (1)? geoid earth surface ellipsoid

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 11 why different systems (2)?

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 12 issues  Conversion –mathematical –exact (exception : N)  Transformation –empirical –precision depending on measurements  All changes –time-consuming –risks of errors, discrepancies

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 13 problems...  Limitless and ever expanding list of ’systems’ (national, regional, local)  Increasing needs for large amount of data to be processed ‘on-the-fly’  What specification to include in the CEC call for tenders ?  Etc...

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 14 … and solutions  SAI / MEGRIN Expert Workshop –Marne la Vallée, 29-30/11/99  15 participants –CEC (JRC, DG13, EUROSTAT) –EEA, EUROCONTROL, MEGRIN, EUROGI –Geodesy Experts : EUREF, ISO, CEN, OGC, CERCO, etc..

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe the European system already exists for the experts  ITRS : the global reference  European Continental Plate moves uniformly ~3cm per year

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 16

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe the European system already exists for the experts  ITRS : the global reference  European Continental Plate moves uniformly ~3cm per year  The EUREF sub-Commission of IAG  ETRS89 – stable – shift to global ITRS known (and WGS84) –transfo. parameters known for most European countries!

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe recommendations  No map projection suitable for all pan- European applications  Geo-referenced co-ordinates for the CEC would be geographic co-ordinates (  ) on ETRS89  NMAs to place 1~2 m. accuracy transformation algorithms in public domain  EUREF/CERCO to collect and manage high accuracy transformations

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe heights  nationally defined heights may differ by several dm. (2.3 m. for Belgium)

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 20

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe heights  nationally defined heights may differ by several dm. (2.3 m. for Belgium)  no uniform European height system available yet  EULN in preparation by EUREF/EUVN  Recommendation : that the CEC adopts the EUVN results when made available

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 22 Conclusions interoperability and integration of data from different sources still a key issue  interoperability and integration of data from different sources still a key issue  co-ordinate interoperability is an easily overcome obstacle: –recommend implementation of the existing common reference systems (ETRS89, EULN) –distribute ‘validated’ transformation tools

6th EC-GIS, Jun 2000, Lyon, France A Spatial Reference System for Europe 23 proceedings edited by JRC/SAI also available athttp://