Estimation Method of Instantaneous Frequency Curve of Floating Small Target Echo in Sea Clutter
A technology of instantaneous frequency and sea clutter, applied in the field of signal processing, can solve the problem of accurate estimation of the instantaneous frequency curve of small targets that cannot be floated, and achieve the effect of reducing estimation error and improving stability.
Active Publication Date: 2018-11-30
XIDIAN UNIV
View PDF4 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0005] The purpose of the present invention is to propose a method for estimating the instantaneous frequency curve of the echo of a small floating target in sea clutter, so as to solve the problem that the above-mentioned prior art cannot accurately estimate the instantaneous frequency curve of the floating small target in the background of sea clutter
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0040] The present invention will be further described below in conjunction with accompanying drawing:
[0041] refer to figure 1 , the implementation steps of the present invention are as follows:
[0042] Step 1. Construct the state equation and observation equation of the nonlinear frequency modulation target signal under the background of sea clutter.
[0043] (1.1) Divide the observation time interval [0, T] into L disjoint sub-intervals: [(k-1)ΔT, kΔT], at the kth observation moment, use chirp time-frequency particles to simulate the target signal the s k (t) is:
[0044]
[0045] where t∈[(k-1)ΔT, kΔT), k=2,3,...,L, a k Indicates the amplitude of the target signal at the kth moment, Indicates the initial phase of the target signal at the kth moment, f k-1 Indicates the target signal s at the kth moment k (t) Doppler frequency of the left endpoint, f k Indicates the target signal s at the kth moment k (t) Doppler frequency of the right endpoint;
[0046] (1...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The present invention discloses a method for estimating the instantaneous frequency curve of the echoes of floating small targets in sea clutters. The method includes the following steps that: 1, the state equation and observation equation of target signals under the background of sea clutters are constructed; 2, a generalized likelihood ratio linear threshold detector is used to calculate particle gain according to the two equations; 3, initial particles are generated, and the total gain of particles is calculated; 4, re-sampling weight is calculated according to the total gain of the particles; 5, re-sampling is carried out through using the re-sampling weight, and the particle gain is updated iteratively, so that particle-gain sets at L time points are obtained, and forward state estimation can be obtained with maximum total gain as an estimation criterion; 6, the state equation and observation equation of the target signals of a backward dynamic system are constructed; 7, observation data input to the backward dynamic system in an reverse order, so that target signal state estimation X<^> can be obtained; and 8, instantaneous frequency curve estimation can be obtained through using X<^>. The method has the advantages of high stability in state estimation and small estimation error, and can be used for the state estimation of target signals in the background of sea clutters.
Description
technical field [0001] The invention belongs to the technical field of signal processing, and in particular relates to a method for estimating an instantaneous frequency curve, which can be used for detecting floating small targets under the background of sea clutter. Background technique [0002] In the field of radar, the detection of low-speed floating small targets on the sea surface is a challenging problem. Due to the weak echo and small Doppler shift of floating targets, they are often submerged in non-Gaussian non-stationary sea clutter. For the detection of such targets, the observation time needs to be long enough, and the radar has high spatial resolution. When the observation time is long, the echo signal is affected by the swell and shows amplitude fluctuation and complex Doppler frequency shift. The known information is that Doppler shift is an unknown smooth function with respect to time. At this time, the nonlinear frequency modulation signal can be used t...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01S7/41
CPCG01S7/414
Inventor 水鹏朗施赛楠蒋晓薇
Owner XIDIAN UNIV