Hello!

1.To estimate the vegetation area included in each ellipse, which spatial analysis fountion could I use?

2. I would like to know how to estimate the vegetation area included in each ellipse, which spatial analysis fountion could I use to "cut" the vegetation polygons with each ellipse?

3.I try to use the ST_intersection but failed,I can not get the intersection of the geom and the footprint;

--create table cont_veg as select a.Time, a.Wdir,a.z0,a.KM_p01a,a.KM_p01b,a.KM_p01c, ST_area(st_intersection(a.footprint, b.ST_Union)) as veg_cont from footprint_ART_def a,veg_uni b where st_intersects(a.footprint, b.ST_Union);

and could you tell me the exactly meaning of the 'veg_cont'?

4.For the rotation angle (radians) of the ellipse in the x,y projection (in ST_makeellipse) how can I get it ?

Thanks in avance!!!

Jinhui chen