Adrian Custer a écrit :
Any chance you could write up a paragraph explaining what's going on
with axis order? I'm assembling notes for an eventual writeup of the
geotools CRS and this seems like an important corner case. The EPSG
CRS's are all in the lat, long order except for 4326 which is long, lat?
Not exactly. In the EPSG database, the axis order is (latitude,longitude) for most geographic CRS,
including EPSG:4326. The problem is that common usage in the field (derived from early WMS
specification, as explained by Jody) expect (longitude,latitude) order, in violation of what EPSG said.
EPSG:4326 was just cited as an example, but the problem apply to about all geographic CRS defined in
the EPSG database. Axis order used in the field (from early OGC WMS specification) for "EPSG:4326"
(and other geographic CRS) are in violation with the real axis order defined in the EPSG database.
It has been proposed that "EPSG:4326" means "CRS with axis order as defined by OGC, not by EPSG",
which seems to me a door opened for confusion since the CRS is called "EPSG:...", which suggest a
CRS defined by the EPSG authority...
An other problem is that "EPSG:4326" as defined by OGC would be inconsistent with usage of "4326" in
the EPSG database itself (for example the "source" and "target" CRS relations in the
"Coordinate_Operations" table).
Martin.
-------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid0709&bid&3057&dat1642
_______________________________________________
Geotools-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/geotools-devel
