Radar Sea Clutter Characteristic Statistical Analysis And Simulation

The performance capability of radar system is the processing ability to deal with the interested targets under various kinds of noise, clutter, and jam environments. The core of Radar echo simulation is modeling the scatter and transmission of radar echo signal and varied radar clutter signals. So it is very important to study the character of radar clutter, with a proper model. And it is very significant to radar design and analysis.Sea surface, as the radar backscatter, is very complex. Sea breeze, ocean current, ocean wave, tides and different water quality has a great effect on sea clutter. In addition, seawater movements, water fluctuations inside, turbulence, the reflection of radar wave between waves, diffraction of the edge of the wave, all of these made the radar spectrum not only a very irregular shape but also the reflex unit probability distribution function beyond the conventional function. Different sea-state clutter amplitudes distribution must use different statistics model to represent, such distributions including Weibull, LogNormal, and K. The purpose of this thesis is to study the sea clutter data measured and find which amplitudes distribution models are applicable for different sea-state clutter. Then, the model was used to simulate different sea-state clutter.First, some models of sea clutter amplitude distribution were introduced. Through the analysis of the IPIX radar sea clutter data, and by the histogram analysis of the I/Q component of the IPIX data, it showed that the low sea-state amplitudes should use K distribution to indicate while the high sea-state amplitudes could use LogNormal or K distribution to describe. At the same time, we analyzed the power spectrum density of different sea-state clutter and found that Gaussian power spectrum density model is suitable to indicate the high and low sea-state clutter. Then the processes of simulation for each clutter were presented. Zero Memory Nonlinearity (ZMNL) transformation is used to simulate the high sea-state LogNormal amplitude distribution clutter; the method of high and low sea-state K amplitude distribution clutter simulation is based on the theory of Spherically Invariant Random Process (SIRP). Finally the experimental results were performed a qualitative and quantitative testing. By using a mapping method for qualitative examination, simulation data was very close to the theoretical distribution of observation. Moreover, using the K-S andχ2 hypothesis testing for the quantitative examination, the simulation data also passed the K-S andχ2 hypothesis testing with a certain confidence level. Actually,a rapid and accurate simulation of radar clutter is necessary for studying sea clutter characteristics and target detection. Simulation of the sea clutter data provides a theoretical basis and foundation for target detection and interference suppression.