High Fidelity Clutter Model for Active Sonar

Active sonar clutter usually appears on a display as an amalgamation of point scatterers that exhibit both object and individual reflective and kinematic behavior. We propose to demonstrate the feasibility of constructing a realistic active sonar clutter model based on a few generalized concepts to synthesize most clutter types observed on Mid-Frequency active sonars. Realism is achieved by using the statistics of known clutter object attributes obtained from existing databases. The clutter model uses superellipsoids to define basic building blocks. Each type of clutter block is populated with discrete point scatters. The population, density, scattering coefficient, velocity, and fading characteristics of the scatterers are described using the appropriate statistics. The acoustic propagation response function for each scatterer is obtained using a high fidelity acoustic model. A realistic time series of a clutter object echo is obtained by convolving the transmit waveform with the system, propagation and clutter object response functions. Because all the functions, save one, are represented as delta functions, this is not computationally intensive. The model includes the effects of own ship motion, the specific sonar design, waveforms, and acoustic propagation including attenuation and multipath arrivals. The clutter exhibits deterministic and stochastically dependent, spatial, temporal, and intensity characteristics.