Method for detecting moving target based on spatial slices of transformed spatio-temporal frequency space

Patent metadata

Field	Value
Publication number	US-12282092-B2
Application number	US-202318120609-A
Country	US
Kind code	B2
Filing date	Mar 13, 2023
Priority date	Apr 22, 2022
Publication date	Apr 22, 2025
Grant date	Apr 22, 2025

Abstract

The present disclosure belongs to the field of underwater target detection, and in particular, to a method for detecting a moving target based on spatial slices of transformed spatio-temporal frequency space. The method includes: segmenting a target radiated acoustic signal received by an M-element horizontal line array in an underwater acoustic environment with a low signal-to-noise ratio (SNR); performing N-point discrete Fourier transform (DFT) on the received signal on each array element in each period of time; performing frequency domain beamforming on an array signal after each section of DFT, and performing stacking after compensating a phase difference between arrays brought by an azimuth of each primitive element; performing coordinate transformation on a frequency-azimuth-time three-dimensional (3D) matrix space obtained; taking a slice from the obtained frequency-azimuth-time 3D space subjected to the coordinate transformation; and performing segmented Radon transform on the spatial slice obtained to detect the target.

First claim

The invention claimed is:

1. A method for detecting a moving target based on spatial slices of transformed spatio-temporal frequency space, comprising the following steps:
step 1: segmenting a target radiated acoustic signal s(t) received by an M-element horizontal line array in an underwater acoustic environment with a low signal-to-noise ratio (SNR);
step 2: performing N-point discrete Fourier transform (DFT) on the received signal on each array element in each period of time τ p in step 1, wherein N=T 0 ·f s ;
step 3: performing frequency domain beamforming on an array signal after each section of DFT in step 2, and performing stacking after compensating a phase difference between arrays brought by an azimuth α(τ p ) of each primitive element;
step 4: performing coordinate transformation on a frequency-azimuth-time (f-α-t) three-dimensional (3D) matrix space obtained in step 3;
step 5: taking a slice from the frequency-azimuth-time (f-cos θ-t) 3D space subjected to the coordinate transformation obtained in step 4; and
step 6: performing segmented Radon transform on the spatial slice obtained in step 5 to detect the target.

2. The method for detecting a moving target based on spatial slices of transformed spatio-temporal frequency space according to claim 1 , wherein step 1 is specifically as follows:
s m (τ p ,n )= s ((τ p −1) T b +n )  (1),

where
τ p =1,2, . . . , P, n= 1,2, . . . , T 0 f s , and m= 1,2, . . . , M , and

P represents a number of segments into which data is divided, τ p represents a p-th segment of signal, T 0 represents a length of each segment of signal, in unit of second, T b represents a segmentation stride, in unit of second, f s is a sampling rate of the signal, τ p represents a slow time, n represents a fast time, and m is an array element number.

3. The method for detecting a moving target based on spatial slices of transformed spatio-temporal frequency space according to claim 1 , wherein step 2 is specifically as follows:

s
⁡
(

τ
p

.
ω

)

=

1
N

⁢

∑

n
=
0

N
-
1

⁢
A
⁢

e

i
⁢

k
→

·

r
→

0

⁢

e

i
⁢

ω
p

⁢

τ
p

[

1

e

-
i

⁢

2
⁢
π
⁢

f
0

c

⁢
d
⁢
cos
⁢

⁢

α
⁡
(

τ
p

)

…

e

-
i

⁢

2
⁢
π
⁢

f
0

(

M
-
1

Assignees

• Univ Harbin Eng

Inventors

• Piao Shengchun
• Shi Yunjia
• Guo Junyuan
• Zhang Minghui

Classifications

• G06F17/11 Primary

  for solving equations {, e.g. nonlinear equations, general mathematical optimization problems (optimization specially adapted for a specific administrative, business or logistic context G06Q10/04)} · CPC title

• G01S15/88

  Sonar systems specially adapted for specific applications (seismic or acoustic prospecting or detecting G01V1/00) · CPC title

• G01S3/801

  Details {(G01S3/82, G01S3/84, G01S3/86 take precedence)} · CPC title

• G01S5/20

  Position of source determined by a plurality of spaced direction-finders · CPC title

• G01S1/76

  Systems for determining direction or position line · CPC title