“…The ensemble of target decorrelation and APS results in a non Gaussian distribution of the data, which complicates the a-priori assessment of the LDF estimator performance for any given scenario. In the existing literature the computation of InSAR lower bounds is commonly approached as the problem of estimating a set of deterministic parameters in presence of decorrelation noise (23), (24), whereas the role of the APS is in general neglected. Within this chapter it will be shown that, under the hypothesis that a single, distributed, target is present within the SAR resolution cell, the roles of target decorrelation and APSs may be jointly treated by exploiting the Hybrid Cramér-Rao Bound (HCRB), where the unknowns are both deterministic parameters and stochastic variables.…”