Linear sampling methods

Z

u

(x^; d)g(d) ds(d); x^ 2 ; (7.1.2)

is known as the far eld operator and

true

denotes the far eld pattern

of the fundamental solution (1.2.40). The far eld operator F has smooth

kernel, is thus compact in L

( ) and in general equation (7.1.1) does not

have a solution. We temporarily assume that we are able to solve (7.1.1)

and in a second step show how to modify the approach to treat the general

case.