[postgis-users] Projection question

[Markus Schaber]

Hi, Ehud,

Ehud Shabtai wrote:

> As I have data from all around the world, is there a single projection
> which would preserve the distance for every location?

Sadly, there is none, as it is geometrically impossible to project a
spherical object into a plain one without loss.

Maybe the best idea is to use a group of zone projections that cover the
whole planet (e. G. UTM) and then write a plpgsql function that maps a
geometry to the appropriate zone srid. This would allow you to write
something like:

transform(buffer(transform(the_geom, find_utm_srid(the_geom)), 100, 4326);'

HTH,
Markus