[postgis-users] Using a buffer with a LineString covering the whole world

[Chris Hermansen]

It might not be that bad, Paul, depending on the latitude of the start
and end points, which - USA <-> France - sounds like they might be
pretty close.  If it was say Seattle Paris, that would be ok.

Paul Ramsey wrote:
> that's really not a good option. mercator does not preserve
> length/distance, so the buffer would end up larger at one end than the
> other, and furthermore would not be the expected width, since it would
> be built far from the latitude of true scale.
>
> P.
>
> On Wed, Feb 11, 2009 at 8:52 AM, Pavel Iacovlev
> <iacovlev.pavel at gmail.com> wrote:
>   
>> As an option you can use google mercator projection for the whole world. But
>> read carefully docs about it to understand the precision loss.
>>
>> http://genuchten.blogspot.com/2008/04/srid-stuff-in-postgis.html would be a
>> good start.
>>
>> On Wed, Feb 11, 2009 at 6:26 PM, Matthes Rieke <matthes.rieke.01 at gmail.com>
>> wrote:
>>     
>>> Hi all,
>>>
>>> I am currently running into this problem: I have a LineString in lat/long
>>> coordinates (SRID 4326 - going from USA to france). I now want to create a
>>> buffer in meters from this. So the normal way to transfrom the coordinates
>>> to a planar CRS, buffering, then transforming back to 4326 does not work
>>> (the Line is covering many UTM zones). What would be a reasonable solution
>>> for this problem?
>>>
>>> Thanks and regards,
>>> Matthes
>>>
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>>>
>>>       
>>
>> --
>> http://iap.md, The future is open
>>
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>>     
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-- 
Regards,

Chris Hermansen         mailto:chris.hermansen at timberline.ca
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