Statistical analysis of achievable resolution limit in the near field source localization context

In this fast communication, we derive the statistical resolution limit (SRL), characterizing the minimal parameter separation, to resolve two closely spaced known near-field sources impinging on a linear array. Toward this goal, we conduct on the first-order Taylor expansion of the observation model a Generalized Likelihood Ratio Test (GLRT) based on a Constrained Maximum Likelihood Estimator (CMLE) of the SRL. More precisely, the minimum separation between two near-field sources, that is detectable for a given probability of false alarm and a given probability of detection, is derived herein. Finally, numerical simulations are done to quantify the impact of the array geometry of the signal sources power distribution and of the array aperture on the statistical resolution limit.

► We derive the statistical resolution limit to resolve two closely spaced known near-field sources. ► We conduct a generalized likelihood ratio test based on a constrained maximum likelihood estimator of the SRL. ► The minimum separation between two near-field sources, that is detectable for a given probability of false alarm and a given probability of detection, is derived herein. ► Numerical simulations are done to quantify the impact of the array geometry, the signal sources power distribution and of the array aperture on the SRL.