STBuffer (geography Data Type)
Returns a geography object that represents the union of all points whose distance from a geography instance is less than or equal to a specified value.
STBuffer() calculates a buffer in the same manner as BufferWithTolerance, specifying tolerance = distance * .001 and relative = false.
A negative buffer removes all points within the given distance of the boundary of the geography instance.
The error between the theorectical and computed buffer is max(tolerance, extents * 1.E-7) where tolerance = distance * .001. For more information on extents, see geography Data Type Method Reference.
The following example creates a LineString geography instance. It then uses STBuffer() to return the region within 1 meter of the instance.
DECLARE @g geography; SET @g = geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656)', 4326); SELECT @g.STBuffer(1).ToString();