[udig-users] Re: epsg 26591

[andrea antonello <andrea.antonello@xxxxxxxxx>]

Hi Laura,
sorry for coming that late.

> There is not a properly direct link. You should go to this webpage
> http://www.cartografia.regione.lombardia.it/usedde/clientDDE.jsp, then
> select a group and a layer. Then you provide your mail address and then they
> will send you the file in few seconds.
>
> I can send some files if you prefer.

I dowloaded the basins file: Bacini_idrografici_10kmq_poly

and apart of some missing features in the middle, the shape looks good
to me and follows well lombardia's bounds.

> I tried again and with the epsg 3003 it works....

Yes, but it should be shifted, right? 3003 uses a different meridian.

> The problem is that with epsg 26591 also the north arrow rotates... I don't
> kow why.
> I also read that the usage of epsg 3003 and 26591 is deprecated (why?)

In the postgis list I found some explanation:

_________________________________
Please remember to use 3003 intead of 26591.
If I remember well there was some kind of offset error using the former.
It has been deprecated by EPSG on 16 Jan 2003 with this motivation:
"Associated with incorrect datum resulting in map projection longitude
being incompatible with prime meridian."

In fact 26591 uses this prime meridian:
	PRIMEM["Rome",12.45233333333333,AUTHORITY["EPSG","8906"]]

while 3003 uses this one:
	PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]]

The same applies for 3004 vs 26592.
_________________________________


My colleague Silvia is going to test the files too and check a bit
better than me.
Let's see what she finds out.

Ciao
Andrea



>
>
> Laura
>
>
>
>
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Sat, 14 Mar 2009 13:47:06 +0100
>> From: andrea antonello <andrea.antonello@xxxxxxxxx>
>> Subject: Re: [udig-users] epsg 26591
>> Cc: udig-users@xxxxxxxxxxxxxxxxxxxxx
>> Message-ID:
>> <116eb44a0903140547q2e1c19b4s5c47d5086fde3042@xxxxxxxxxxxxxx>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> Hi Laura,
>> could you supply me a direct link to the data in order to test them?
>>
>> Ciao
>> Andrea
>>
>> On Wed, Mar 11, 2009 at 11:31 PM, Laura <bisnulama@xxxxxxxxxxx> wrote:
>>>
>>> I am still having that problem with epsg 26591.
>>>
>>> The shp files I am using from the Lombardia website have this things
>>> written
>>> in their prj:
>>>
>>> PROJCS["Monte Mario (Rome) / Italy zone 1",'
>>> GEOGCS["unnamed",
>>>
>>> DATUM["D_unnamed",SPHEROID["International_1924",6378388,297.0000000000601]],
>>> PRIMEM["Greenwich",0],
>>> UNIT["Degree",0.017453292519943295]],
>>> PROJECTION["Transverse_Mercator"],
>>> PARAMETER["latitude_of_origin",0],
>>> PARAMETER["central_meridian",8.999999999999998],
>>> PARAMETER["scale_factor",0.9996],
>>> PARAMETER["false_easting",1500000],
>>> PARAMETER["false_northing",0],
>>> UNIT["Meter",1]]
>>>
>>> If I load these files they have their epsg 26591 recognized by udig
>>> correctly.
>>> If the epsg of the project is 26591 something wrong happens: the map,
>>> wich
>>> has a rectangular shape is rotated, about 30 degrees west, I mean, it is
>>> a
>>> rectangle but the north of the map heads north-west...
>>> If I set an epsg code 23032 for the project North heads north, which is
>>> ok.
>>>
>>> Can someone help me?
>>> Thanks a lot!
>>>
>>> Laura
>>> _______________________________________________
>>> udig-users mailing list
>>> udig-users@xxxxxxxxxxxxxxxxxxxxx
>>> http://lists.refractions.net/mailman/listinfo/udig-users
>
>
>