5. Appendix: effect of GN

The power associated with each pixel of \(I_{GN}\) can be expressed as [RD4]

(1)\[\left\vert I_{GN}(r,\ a) \right\vert^2=\ 2\int_{}^{}{{\sigma({r,\ a,\ z})}^2\left[ 1-\cos({k_z(r,a)z}) \right]}\ dz \tag{5.1}\]

where \({\sigma({r,\ a,\ z})}^2\) is the uncorrelated reflectivity density of the distributed target along z, and \(k_z(r,\ a)\ =\ k_z(r,\ a,\ 1)\ -\ k_z(r,\ a,\ 2)\) is the interferometric pair vertical wavenumber.