In a system for determining the direction of a received signal, e.g. a reflected radar signal or a signal from a remote transmitter, a directional receiving antenna having a directive pattern, such as that shown
Such a theorem comes from directional derivative considerations of a convex functional and is discussed in design monographs like (Fedorov 1972; Berger and Wong 2005). For example, if m is the dimension of θ and δx is the design that takes all observations at x, it can be shown that ...
on one straight line, but belonging to the same plane; defining separate points of an intersection of the spheres; the number of such points can be equal either to zero or one, or two; determining a single valid point; and calculating a position of the transponder from this one point. ...
the directional magnetometers of the same pair being located on the same axis of a trihedron in symmetrical manner with respect to the centre of said trihedron, said plurality of magnetometer pairs being disposed in such a way as to measure the tensor of the gradient of the magnetic field vec...