Coherent Target Detection in Heavy-Tailed Compound-Gaussian Clutter
Presented by Prof. Fulvio GINI on 16 Oct 2012 from 15:50 to 17:50
Track: Coherent target detection
Coherent radar target detection is the subject of the second part of the talk. In high resolution radar systems the disturbance cannot be modelled as Gaussian distributed and the classical detectors suffer from high losses. Then, according to the adopted disturbance model, optimum and sub-optimum detectors are derived and their performance analyzed against a non-Gaussian background. First, the problem of detecting completely known and fluctuating random signals, possibly with unknown parameters, against correlated non-Gaussian clutter modelled as a compound-Gaussian process is then described exploiting different degrees of knowledge on target and clutter statistical characteristics. A generalized likelihood ratio test (GLRT) detector and a fully adaptive constant false alarm rate (CFAR) detector are derived and different novel interpretations of the detection algorithms provided in order to highlight the relationships and the differences among them and the links with the Gaussian clutter case. Each interpretation suggested different ways to implement the optimum detector and allowed to derive sub-optimum detectors easier to implement than the optimum and with very low losses. Modern radar systems generally operate in non-homogeneous and non-stationary clutter environment. In this condition the amplitude statistics and the power spectral density of the disturbance are unknown. Therefore, the adaptive versions of the algorithms previously described, which estimate the clutter covariance matrix, are then introduced. An estimation algorithm is described which guarantees the CFAR property and its performance are investigated and compared to that of the maximum likelihood (ML) estimator. The important cases of target signal partially unknown or modelled as a subspace random process are also analyzed. The proposed detectors are tested against both simulated data and measured high resolution sea clutter data to investigate the dependence of their performance on the various clutter and signal parameters.
Location: EGO, Cascina
Address: The European Gravitational Observatory (http://www.ego-gw.it), site of the Virgo interferometer, is located in the countryside of the Comune of Cascina, a few kilometres from town of Pisa.