A Design Method of Sea Clutter Suppression Curve for Marine Radar Based on Wavelet Transform

Abstract

The invention relates to a design method for a sea clutter inhibition curve of a marine radar based on wavelet transformation, and belongs to the technical field of signal processing of the marine navigation radar. Echo data of the radar in the measuring range is decomposed via discrete wavelet transformation, a high-frequency coefficient is zeroed, and a high-level approximate part is used to estimate power level of sea clutters. A corresponding adjustable sea clutter inhibition curve is calculated according to a range parameter and a sea clutter inhibition intensity parameter, and the estimated power level of the practical sea clutters is overlapped with the adjustable sea clutter inhibition curve to obtain a general sea clutter inhibition curve. The inhibition curve design method is highly adaptive to a traditional sea clutter inhibition method relied on statistical characteristics, it is not required to predict distribution which the power level of background clutters obeys in advance, the method has a good inhibition effect for near sea clutters, and the problem that sea clutters surrounding the circular center of a radar screen are hard to eliminate is overcome; and the design method is flexible to use, and includes different inhibition levels, so that a user can carry out sea clutter inhibition of different levels according to practical sea-condition information.

Description

technical field [0001] The invention belongs to the technical field of marine navigation radar signal processing, and relates to a method for designing a sea clutter suppression curve for marine radar based on wavelet transform. Background technique [0002] In recent years, the shipbuilding industry has developed vigorously, and the supporting shipboard electronics industry has also developed rapidly. Ship navigation radar is one of the necessary equipment for civil ships to sail, and its function is directly related to market competitiveness. The main criterion for measuring a radar is to measure the accuracy and effectiveness of the radar's clutter suppression. Navigational radar mainly operates on the sea surface, and clutter mainly comes from ocean waves. Therefore, how to effectively filter out ocean clutter is a subject that people have been studying all the time. [0003] The traditional sea clutter suppression method is to use the STC curve. On the one hand, the S...

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Problems solved by technology

In recent years, most of the radar products purchased by most coastal fishermen are foreign radars, such as Furuno of Japan and Atlas of Germany. Most of the small and medium-sized radar receivers of these companies use logarithmic intermediate frequency amplifiers, which are sent to the baseband after linear envelope detection. Although the logarithmic intermediate frequency amplifier can suppress the strong radar echo signal at close range to a certain extent, the echo signal in the near range is still higher than the signal strength in the distance. If it is directly used for detection and judgment, it will be found that the radar screen is close to The distance circle at the center of the circle is basically occupied by radar clutter, and it is impossible to distinguish between the target and the clutter. Even with constant false alarm processing, the effect is still not significant

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