[postgis-users] Ellipses and WGS84

[David W Talmage - CONTRACTOR]

Bruce Rindahl wrote:
> Your parameter r is in map units.  For your example r = 1 or a 1 degree 
> circle.  The center section should be :
> buffer(GeomFromText('Point(0.0 0.0)', 4326), 1)
> Now you have a circle (polygon actually) with a radius of 1 unit 
> (degrees) centered at point 0,0.
> Next you need to scale the circle to create an ellipse.  You do this 
> with the scale factors a and b.  These parameters are dimensionless 
> (ratios).
 >...

Ratios!  I get it now.  Thanks!  My SELECT now works as I expected it to.