[postgis-users] simplify
Brent Wood
pcreso at pcreso.com
Thu Mar 1 14:59:26 PST 2007
--- Stephen Crawford <src176 at psu.edu> wrote:
> OK, I lied about the "last question for today" thing:
>
> I understand about simplifying on decimal degrees data, but I really want to
> keep the data in WGS84 and then reproject in Geoserver as needed. To
> simplify, should I first Transform() to, say, Mercator, then Simplify(),
> then transform back to WGS84? That seems like ti would be the same problem.
> And most other projections are not appropriate for such a large area....my
> data are for the entire Western Hemisphere.
I do this type of thing routinely to calculate distances & areas, as well as
simplify vessel tracklines & transect datasets. I'm working from 20S to 80S so
there is no way I can use the native coordinate system to generate useful
numbers in PostGIS.
Data stored in EPSG:4326 (lat long) is transformed to an appropriate
equidistant or equal area projection to generate what I require, then that (if
it is a geometry) is transformed back to EPSG:4326.
Cheers,
Brent Wood
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