A class of singular Fourier integral operators in synthetic aperture   radar imaging
  In this article, we analyze the microlocal properties of the linearized forward scattering operator $F$ and the normal operator $F^{*}F$ (where $F^{*}$ is the $L^{2}$ adjoint of $F$) which arises in Synthetic Aperture Radar imaging for the common midpoint acquisition geometry. When $F^{*}$ is applied to the scattered data, artifacts appear. We show that $F^{*}F$ can be decomposed as a sum of four operators, each belonging to a class of distributions associated to two cleanly intersecting Lagrangians, $I^{p,l} (\Lambda_0, \Lambda_1)$, thereby explaining the latter artifacts. 
G. Ambartsoumian, R. Felea, V. P. Krishnan, C. Nolan and E. T. Quinto
math.AP math.DG