Abstract:
Accurate detection of maritime targets in all adverse weather conditions requires detailed knowledge and a correct understanding of the signals reflected by the sea surface and its environment. The first objective proposed in this thesis is to find a statistical model that accurately describes the behavior of the intensive sea echo ""Clutter"", and provides a precise long tail. Under this context, two approximate Weibull models with thermal noise are proposed to describe high-resolution sea clutter. For the first model, we derive the expressions of the PDF and CCDF for single and multiple pulses. For the second model, we also derive the expression of the CCDF for single as well as multiple pulses. In addition, we provide the formula of the moments. The parameters estimation for each model is conducted using the PCFE method of the CCDF function based on the N-M algorithm. The simulations were carried out on synthesized sea data as well as on real sea data collected by the McMaster IPIX radar. All the results obtained from synthesized and real IPIX data with a different range resolution (60, 30, 15, 9, and 3 meters) and different polarization modes (HH, VV, HV, and VH) confirmed that the proposed models provide the best-fit performance for sea data, especially in the tail regions, outperforming the CG models with additive thermal noise in most cases. The second work in this thesis is based on the mixture of a proposed Weibull models. In all cases studied, the proposed model provides an accurate fit to the actual IPIX sea data and shows a precise tail, outperforming the mixture of the CG models. Finally, in the context of maritime radar detection, two novel CFAR detectors are suggested for Weibull and CG models with the presence of thermal noise and interfering targets. The proposed detectors have been studied on the basis of synthesized data and real IPIX data. All the results show a high probability of detection as well as an excellent false alarm rate regulation, especially in the case of the presence of spiky clutter.
