Joint fractal-based method for detecting small target under sea clutter background

A small target detection and sea clutter technology, applied in radio wave measurement systems, instruments, etc., can solve the problems that the chaotic characteristics of sea clutter have not been fully verified theoretically, and the prediction model does not have ergodicity, etc., and achieve high detection probability Effect

CN102914769AInactive Publication Date: 2013-02-06NANJING UNIV OF INFORMATION SCI & TECH
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2013-02-06
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a joint fractal-based method for detecting a small target under a sea clutter background. The joint fractal-based method is higher in detection probability. The detection problem of a non-additive model is transformed into a classification problem, i.e. whether a target exists or not is equivalent to belong to a class in which a pure sea clutter exists, and a characteristic joint detection algorithm is provided. A bilogarithmic graph is established by using a trend fluctuation method through sea clutter data, a slope, namely a Hurst index, is fitted by using a least square method within a scale-free interval, and is used as a characteristic scalar, a nodal increment of a keypoint in the bilogarithmic graph is used as another characteristic scalar, therefore, a double-scalar obtained by each group of sea clutter data corresponds to one point in the bilogarithmic graph, n groups of corresponding points (i=1,...n) of the pure sea clutter data are obtained by using the steps, a space optimal classification line omega is obtained by using a convex hull function, sea clutters of regions in which the target possibly exits are obtained by using the same steps, and finally, by using whether the points exist in the space optimal classification line omega or not as a criterion, when the points exists in the space optimal classification line omega, no target exists, and when the points are outside the space optimal classification line omega, the target exists.
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Description

Technical field:

[0001] The invention relates to the field of radar data processing, in particular to a radar detection method for a sea target and a sea clutter detection method. Background technique:

[0002] Sea clutter is the backscattered echo from a piece of sea surface illuminated by the radar transmission signal. When the radar detects the target above or close to the sea surface, it must overcome the interference of the echo of the sea surface itself. When the radar reflection cross-section (RCS) of a weak target on or near the sea is small, its radar echo is often lost in sea clutter and noise, and sea clutter is also affected by radar polarization, operating frequency, and antenna angle of view. And sea conditions, wind direction and other factors, showing obvious non-stationary, non-Gaussian, making it difficult to describe the sea clutter with a fixed statistical model.

[0003] Through the precise analysis of sea clutter in the time domain, explore the essenti...

Examples

Embodiment Construction

[0019] Step 1 takes the echo data of the fully coherent radar as input, recorded as x(i)i=1,2,...,N (N is the length of the input echo data, generally 2 15 ), subtract the average value from x(i), calculate the local sum, and establish a new sequence.

[0020] Y ( i ) = Σ k = 1 i [ x ( k ) - x > ] , ( i = 1,2 , · · · , N ) - - - ( 1 )

[0021] Where is the mean value of the input echo data.

[0022] Step 2 Divide the new sequence Y(i) into N of length m m =int(...