[postgis-users] Anti-meridian and polar polygon question

[Ken Tanaka]

Hello,

 I'm new to this list and have a general question on PostGIS's 
capabilities. I spent a little time searching the list archives, but 
didn't see this question asked before. Are polygons that cross the 
anti-meridian (international date line) or encircle the poles allowed?

For example is it valid to define a 2x1 degree Pacific box with lon,lat 
coordinates of 179,0 -179,0 -179,1 179,1? Could I then expect to get 
correct area calculations or select other geometry within 100km of this 
area?

(text diagram, use monospaced font)
       180
179,1   :   -179,1
  +----------+
  |     :    |
  +----------+
179,0   :   -179,0

I was also wondering if PostGIS can similarly deal with a polygon that 
goes around a pole, like the coastline of Antarctica?

The Informix DB with the Geodetic Datablade option handles these, but 
does anyone know of other spatially enabled databases that can also do 
this, either free or commercial? I'm involved with a system design team 
that is monitoring GIS capabilities available.

Thanks,
Ken

-- 
= Geospatial Data Services Group ==================
| CIRES, National Geophysical Data Center / NOAA  |
| 303-497-6221                                    |
= Ken.Tanaka(a)noaa.gov ===========================