The Sidelobe Suppression Techniques And Characteristics Of Sea Clutter Of The Surveillance Radar On Sea

Shore-based detection radar is an important component of coastal defense system. This paper mainly studies on the signal processing technology of the shore-based detection radar and focuses on the side-lobe suppression and sea clutter in the environment. Experimental data give enough support to the theoretical analysis.Pulse compression technology is achieved by the matched filter. However, the matched filter suffers with the range sidelobe which will mask the small scatters nearby. In order to solve the problem and improve the performance of pulse compression, the traditional way is to use window function. Other optimization methods used in the time domain have two main categories: one is optimal filtering, including the recursive least squares, weighted least squares algorithm, minimum mean square error algorithm, etc; the other is the iterative approximation algorithm such as the recursive least mean square error algorithm and its modified algorithms. The algorithms are compared in the content and performance. The comparison results show that iterative approximation algorithm has a better performance on sidelobe suppression. This paper analysis the disadvantages of each method and propose a preliminary solution.However, the sidelobe problem is not only present in the match filter, but also in Doppler filter. As amplitude frequency response of transversal filter also suffers with the sidelobe. It will result in the peak of the output waveform broadening, and mask the small scatters nearby. window functions and the optimal filter method can suppress the sidelobe in Doppler filter.Detection radar sea clutter will suffer interference of the sea clutter. The paper analyzes sea clutter on the X-band in the magnitude distribution of experimental data, calculates sea clutter power spectral density, temporal correlation and spatial correlation. According to the characteristics of sea clutter, analyze the impact of detection. By analyzing the characteristics of ship motion in waves, Doppler shift of each movement pattern is calculated, according to sea clutter and ship motion spectral bands, qualitative and quantitative analysis The impact to imaging information from sea clutter. Used the experimental sea clutter data we can sea that then the ship sailing in the radial velocity of 0.9m / s to 2.34m / s, the sea clutter band and the target band aliased.