Re: Define spatial reference system for local datum

>
> Thank you for your help Sean and Ralf.
>
> When I load polygon table with srid of -1, Udig keeps saying undefined
> spatial reference...unexpected behavior might occur...etc.   And when I try
> to edit the layer, the layer constantly flashing and Udig crashes.
>
>
>
> Sean Fulton wrote:
>>
>> I'm not sure why you want to assign it an SRS of EPSG:4326.
>>
>> uDig will load and Quantum GIS will happily load and edit the layers if
>> you assign an SRID of -1.
>>
>>
>> Sean
>>
>>
>> On 2009-07-01 16:36:44 -0400, tommy408 <tommytomorow@...> said:
>>
>>>
>>> A lot of these tools that connect to postigs db requires a srid.  I was
>>> trying out Udig.  I don't need to use these tools.  I can just work with
>>> shapefile and import it to postgis.
>>>
>>> But what I'm worry about is if I use a defined srid like EPSG:4326 and my
>>> personal map coordinates will mess up because of the projection.  The
>>> world
>>> I'm mapping is flat and endless, it doesn't wrap around like earth map.
>>>
>>>
>>>
>>>
>>> Sean Fulton wrote:
>>>>
>>>> Can you just set the SRID to -1.  What 'map design tool' are you
>>>> using?
>>>>
>>>> Sean
>>>>
>>>> On Jun 30, 3:00 pm, tommy408 <tommytomo...@...> wrote:
>>>>> I'm not mapping anything on earth.  The world I'm doing is flat.  The
>>>>> polygons I'm drawing over is raster image I made.  So I'm trying not to
>>>>> use
>>>>> any ellipsoid projection.
>>>>>
>>>>>
>>>>>
>>>>> Suhr, Ralf wrote:
>>>>>
>>>>>> Do not use a local system. For everything larger than 200meters you
>>>>> need a
>>>>>> srs definition, because you can't messure it exactly.
>>>>>
>>>>>> Take a projection from your living area und shift your geometrys to
>>>>>> the
>>>>>> right place.
>>>>>
>>>>>> -----Ursprüngliche Nachricht-----
>>>>>> Von: postgis-users-boun...@...
>>>>>> [mailto:postgis-users-boun...@...] Im Auftrag von
>>>>>> tommy408
>>>>>> Gesendet: Dienstag, 30. Juni 2009 12:26
>>>>>> An: postgis-us...@...
>>>>>> Betreff: [postgis-users] Define spatial reference system for local
>>>>> datum
>>>>>
>>>>>> I don't need special projection.  My map is a flat plane so I'm trying
>>>>> to
>>>>>> use local datum as my srs because a bunch of gis map design tool ask
>>>>> for
>>>>>> it.
>>>>>
>>>>>> So I'm trying to add a new srs into postgis spatial_ref_sys table with
>>>>> the
>>>>>> following srstext
>>>>>
>>>>>> LOCAL_CS["Non-Earth (Meter)",LOCAL_DATUM["Local
>>>>>> Datum",0],UNIT["Meter",
>>>>>> 1],AXIS["X",EAST],AXIS["Y",NORTH]]
>>>>>
>>>>>> What do I put for proj4text?
>>>>>> --
>>>>>> View this message in context:
>>>>>> http://www.nabble.com/Define-spatial-reference-system-for-local-datum...
>>>>>> Sent from the PostGIS - User mailing list archive at Nabble.com.
>>>>>
>>>>>> _______________________________________________
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>>>>>
>>>>> --
>>>>> View this message in
>>>>> context:http://www.nabble.com/Define-spatial-reference-system-for-local-datum...

>>>>>
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