The radar sensor has proven to be an invaluable tool to civilian agencies and military forces for the undertaking of wide area surveillance. Conventional radar signal processing is performed in the single dimension of time, that is, a time series of data received from a single channel is analysed for the presence of targets. There was considerable interest in the idea that the dynamic behavior of radar returns from sea clutter might be modelled as a chaotic dynamical system. The chaotic paradigm was investigated for high-resolution radar case where it was postulated that only the underlying texture component was chaotic in nature. The chapter presents a brief overview of the radar detection problem as it applies to the wide area surveillance of targets, and discusses a series of detection strategies of increasing complexity for addressing increasingly difficult target detection scenarios. It reviews the basic aspects of detection theory through stochastic models of land and sea clutter, and the Swerling models.