The EPSG Contract

[Daniel Morissette]

And about WMS 1.3, because of the mess that Paul described below there 
is no plan to support WMS 1.3 in MapServer in the forseeable future (or 
more specifically, I am not planning to do it anytime soon). I think WMS 
1.1.1 is still the most popular out there anyway and might be for a bit.

Daniel


Paul Ramsey wrote:
> Well, the news from OGC on the WFS/GML issue seems to be to accept  the 
> implemented facts on the ground for older representations of epsg  codes 
> ("EPSG:XXXX") and enforce the "consistent" behavior for newer  
> representations of epsg codes (urn notation).  And the WMS 1.3  
> specification remains as writ, so when Mapserver implements 1.3 it  will 
> need to follow the specification, such as it is.
> 
> This implies, incidentally, some extra infrastructure at the backend,  
> because the current Mapserver source of EPSG CRS information, the  proj4 
> library, does not include ordinate order in its backend epsg  database 
> (the epsg file).  That leaves a pair of unpleasant  implementation 
> paths: add a whole new concept into proj4, and then  have mapserver 
> require the new library version in order to support  WMS 1.3; or do a 
> hack solution and simply assume all +proj=longlat  combinations have 
> reversed ordinates, unfortunately the hack will  omit other cases, like 
> several south african and some european  projects, that also have a 
> northing/easting order.
> 
> So long story long: no news :)
> 
> P
> 
> On Jan 7, 2006, at 8:30 AM, Arnulf Christl wrote:
> 
>> Any news here? Sorry if i missed it. We want to support 1.3 and are  
>> trying to get an overview of which services will support it in  which 
>> way. We are the poor last layer and have to deal with  whatever you 
>> spit at us.
>>
>> Best, Arnulf
>>
>>
>> Paul Ramsey wrote:
>>
>>> I have also tried the Intergraph WFS and it is in easting/ northing, so
>>> that makes 3 so far:
>>>   Mapserver
>>>   Cubewerx
>>>   Intergraph
>>> Will be interesting to hear what the wfs list says.
>>> Frank Warmerdam wrote:
>>>
>>>> On 5/19/05, Paul Ramsey <pramsey at refractions.net> wrote:
>>>>
>>>>> Is it so bad to suck it up and follow the standards consensus,  no 
>>>>> matter
>>>>> how silly? Sometimes bad decisions are made, but walking away  from 
>>>>> the
>>>>> process destroys all the good decisions too.
>>>>
>>>>
>>>>
>>>>
>>>> Paul,
>>>>
>>>> I do see your point, and I have certainly accepted that when  MapServer
>>>> implements WMS 1.3 it will have to address this issue properly.   
>>>> However,
>>>> the WFS stuff has existed for quite a while (as has GML) but this  
>>>> issue
>>>> is only being raised now in the WFS/GML context.  So we are left
>>>> having to back-fix without any obvious indicate of what is really  
>>>> the right
>>>> thing to do.
>>>>
>>>> I *suspect* that at least for GML 2 the coordinate system does not
>>>> control order of values in coordinate tuples.  I'm sure I have heard
>>>> previous detailed discussios to this effect.  I am not at all  sure of
>>>> the situation with GML3.
>>>>
>>>> Hopefully we can isolate these issues to GML3 and WMS 1.3+ so that
>>>> a simple version check will suffice to make the decision clear.
>>>>
>>>> Best regards,
> 
> 


-- 
------------------------------------------------------------
  Daniel Morissette               dmorissette at dmsolutions.ca
  DM Solutions Group              http://www.dmsolutions.ca/
------------------------------------------------------------