The free induction decay (FID) in the MRI of an object can be approximated as
\[
s(t)=\iint m(x,y)\,e^{-j2\pi\,(K_x(t)x+K_y(t)y)}\,dx\,dy,
\]
where \(K_x(t)=\int_0^t G_x(\tau)\,d\tau\) and \(K_y(t)=\int_0^t G_y(\tau)\,d\tau\).
Here \(G_x\) and \(G_y\) are pulses of identical period and are in–phase. By changing the amplitude of the pulses, one can obtain the two–dimensional Fourier transform of the object __________________.