[gdal-dev] Buffer unit

[Iván Sánchez Ortega]

El Miércoles, 9 de octubre de 2013 07:33:43 Federico Jurio escribió:
> Dear all, I am using WGS84 (4326) and would like to buffer based on meters
> and not degrees. [...]
> Can someone please point me in the right direction?

If you have a working PostGIS instance, you can get your geometries as PostGIS 
geographies, then run st_buffer on them. PostGIS will take care of the dirty 
work of finding a more-or-less appropiate projection for buffering the 
geography.


> [buffering in degrees] is the easy way and i'm sure that the accuracy isn't 
> the best.
> [reprojecting] probably doesn't have the best performance.

This begs the question: What do you want to achieve? Accuracy, or performance?


Personally, if PostGIS geographies aren't available, I'd rather reproject 
whole geometries into WGS84 UTM (EPSG:326xx) depending on the centroid's 
longitude, then buffer, then project back into WGS84 lat-lon (EPSG:4326).


Best,
-- 
Iván Sánchez Ortega <ivan at sanchezortega.es>