procedure qds2( buff, nx, ny, x, y, sgnl, sgnln)

# determine aperture signal and area

int	nx
int	ny
real	buff[nx,ny]
int	x
int	y
double  sgnl
int     sgnln
define	SIZE 21
int 	xxx[SIZE]
data  	xxx/ 2,3,4,
           1,2,3,4,5,
           1,2,3,4,5,
           1,2,3,4,5,
             2,3,4/
int 	yyy[SIZE]
data	yyy/ 1,1,1,
	   2,2,2,2,2,
	   3,3,3,3,3,
	   4,4,4,4,4,
	     5,5,5/
int	xx[5]
int	yy[5]
real	px
int	k

begin

xx[1] = x - 2
xx[2] = x - 1
xx[3] = x
xx[4] = x + 1
xx[5] = x + 2

yy[1] = y - 2
yy[2] = y - 1
yy[3] = y
yy[4] = y + 1
yy[5] = y + 2

sgnl = 0
do k = 1, SIZE {
   px = buff[xx[xxx[k]],yy[yyy[k]]]
   sgnl = sgnl + px
}

sgnln = SIZE

end
#