The srid of the geometry the identifier in the spatial_reference_sys table that defines the datum, coordinates of your geometry etc of the geometry in question). Spatial reference system of the geometry. If your st_srid(the_geom) = -1 and you fed it to distance_sphere/distance_spheroid, it wouldn't matter as long as your coordinates are actually measured along the ellipsoid you specify (or approximate ellipsoid of distance_sphere). The distance_sphere never takes a spheroid as I recall - and always assumes a sphere and is faster than spheriod but less accurate.
Hope that helps, Regina ________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Willy-Bas Loos Sent: Tuesday, September 09, 2008 8:56 AM To: PostGIS Users Discussion Subject: Re: [postgis-users] why specify spheroid? > distance_sphere and distance_spheroid don't even look at the srid of the geometry fed to them Why is that? ----------------------------------------- The substance of this message, including any attachments, may be confidential, legally privileged and/or exempt from disclosure pursuant to Massachusetts law. It is intended solely for the addressee. If you received this in error, please contact the sender and delete the material from any computer.
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