The EPSG Contract

Arnulf Christl arnulf.christl at CCGIS.DE
Tue Jan 10 13:28:51 EST 2006


Daniel Morissette wrote:
> 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:

Thanks for the news, I did not exactly expect it to be good news 
anyway... :-)

Does anybody know of a WMS that is accessible online/free for testing 
purposes that can switch serving 1.1.1 and 1.3 on the fly "correctly"? 
It gives me a headache overlaying WMS 1.1.1 and 1.3 in one client.

Probably we will have to stick to 1.1.1 until this issue has been 
resolved at a "global" scale. Pity for the other stuff that gets 
supported in 1.3 though.

Messymessymessy.

Best,

>> 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,
>>
>>
>>
> 
> 



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