Method and device for suppressing range ambiguity
A method and device for suppressing range ambiguity and a computer readable storage medium are provided. The method includes: determining a pulse timing relationship of a transmission signal; determining orthogonal nonlinear frequency modulation signals; modulating the transmission signal by using the orthogonal nonlinear frequency modulation signals; transmitting the modulated transmission signal according to the pulse timing relationship, and determining echo data of the modulated transmission signal; and generating an image according to a polarization scattering matrix for the echo data of the modulated transmission signal.
1. A method for suppressing range ambiguity, comprising:
determining a pulse timing relationship of a transmission signal;
determining orthogonal nonlinear frequency modulation signals;
modulating the transmission signals by using the orthogonal nonlinear frequency modulation signals;
transmitting the modulated transmission signal according to the pulse timing relationship, and determining echo data of the modulated transmission signal; and
generating an image according to a polarization scattering matrix for the echo data of the modulated transmission signal,
wherein determining the orthogonal nonlinear frequency modulation signals comprises:
determining a time-frequency relationship function of nonlinear frequency modulation signals according to a piecewise linear function, and determining a time domain function of the nonlinear frequency modulation signals according to the time-frequency relationship function;
determining a correlation performance parameter of the nonlinear frequency modulation signals according to the time domain function, and determining a mathematical model of the nonlinear frequency modulation signals according to the correlation performance parameter;
initializing the nonlinear frequency modulation signals according to pulse width and bandwidth settings of the nonlinear frequency modulation signals; and
performing iteration on the initialized nonlinear frequency modulation signals by using an augmented Lagrange algorithm according to the mathematical model to obtain the orthogonal nonlinear frequency modulation signals.
2. The method of claim 1 , wherein determining the pulse timing relationship of the transmission signal comprises:
determining the pulse timing relationship of the transmission signal according to a pulse repetition frequency of the transmission signal, wherein the pulse timing relationship is represented as PRI=1/PRF, and PRF denotes the pulse repetition frequency of the transmission signal.
3. The method of claim 1 , wherein the transmission signal comprises a left circular polarization signal and a right circular polarization signal, and modulating the transmission signal by using the orthogonal nonlinear frequency modulation signals comprises:
modulating the left circular polarization signal by using s 1 , and modulating the right circular polarization signal by using s 2 , s 1 and s 2 being the orthogonal nonlinear frequency modulation signals.
4. The method of claim 1 , further comprising: determining the polarization scattering matrix for the echo data of the transmission signal, and
transmitting the modulated transmission signal according to the pulse timing relationship and determining echo data of the modulated transmission signal comprises:
alternately transmitting the modulated transmission signal according to the pulse timing relationship; and
determining the echo data of the modulated transmission signal according to the pulse timing relationship and the polarization scattering matrix, the echo data of the modulated transmission signal being represented in a form of the polarization scattering matrix S CTLR ,
S
C
T
L
R
=
(
S
H
L
S
H
R
S
VL
S
VR
)
,
where,
S HL = +j ,( s 1 )
S HR = −j ,( s 2 )
S VL = +j ,( s 1 )
S VR = −j ,( s 1 ),
S HL denotes an echo of an echo channel having a transmission channel L and a receiving channel H for the modulated transmission signal, S HR denotes an echo of an echo channel having a transmission channel R and a receiving channel H for the modulated transmission signal, S VL denotes an echo of an echo channel having a transmission channel L and a receiving channel V for the modulated transmission signal, S VR denotes an echo of an echo channel having a transmission channel R and a receiving channel V for the modulated transmission signal, L denotes an electromagnetic wave polarization manner of left circular polarization, R denotes an electromagnetic wave polarization manner of right circular polarization, H denotes an electromagnetic wave polarization manner of horizontal polarization, and V denotes an electromagnetic wave polarization manner of vertical polarization.
5. The method of claim 4 , wherein the polarization scattering matrix S CTLR for the echo data of the transmission signal is represented as
S
C
T
L
R
=
(
S
H
L
S
H
R
S
VL
S
VR
)
,
where S HL denotes an echo of an echo channel having a transmission channel L and a receiving channel H, S HR denotes an echo of an echo channel having a transmission channel R and a receiving channel H, S VL denotes an echo of an echo channel having a transmission channel L and a receiving channel V, S VR denotes an echo of an echo channel having a transmission channel R and a receiving channel V, L denotes an electromagnetic wave polarization manner of left circular polarization, R denotes an electromagnetic wave polarization manner of right circular polarization, H denotes an electromagnetic wave polarization manner of horizontal polarization, and V denotes an electromagnetic wave polarization manner of vertical polarization.
6. The method of claim 4 , wherein determining the polarization scattering matrix for the echo data of the transmission signal comprises:
determining ground object scattering coefficients S HL S HR S VL and S VR in the polarization scattering matrix S CTLR , where,
S HL = +j
S HR = −j
S VL = +j
S VR = −j ,
where , , and denote echoes of a linear polarimetric echo channel, denotes an echo of a linear polarimetric echo channel having a transmission channel H and a receiving channel H, denotes an echo of a linear polarimetric echo channel having a transmission channel V and a receiving channel H, denotes an echo of a linear polarimetric echo channel having a transmission channel H and a receiving channel V, denotes an echo of a linear polarimetric echo channel having a transmission channel V and a receiving channel V, L denotes an electromagnetic wave polarization manner of left circular polarization, R denotes an electromagnetic wave polarization manner of right circular polarization, H denotes an electromagnetic wave polarization manner of horizontal polarization, and V denotes an electromagnetic wave polarization manner of vertical polarization; and
obtaining the polarization scattering matrix for the echo data of the transmission signal according to the ground object scattering coefficients S HL , S HR , S VL and S VR .
7. The method of claim 1 , wherein generating the image according to the polarization scattering matrix for the echo data of the modulated transmission signal comprises:
determining a quadruple polarimetric image of a hybrid polarimetric synthetic aperture radar (SAR) system according to the polarization scattering matrix for the echo data of the modulated transmission signal; and
determining a quadruple polarimetric image of a quadrature polarimetric SAR system according to the quadruple polarimetric image of the hybrid polarimetric SAR system,
wherein the quadruple polarimetric image of the quadrature polarimetric SAR system comprises:
S
H
H
=
1
2
·
(
S
H
L
+
S
H
R
)
S
H
V
=
1
2
j
·
(
S
H
L
-
S
H
R
)
S
V
H
=
1
2
·
(
S
V
L
+
S
V
R
)
S
VV
=
1
2
j
·
(
S
V
L
-
S
V
R
)
,
where S HH denotes an image of a quadrature polarimetric echo channel having a transmission channel H and a receiving channel H, S HV denotes an image of a quadrature polarimetric echo channel having a transmission channel V and a receiving channel H, S VH denotes an image of a quadrature polarimetric echo channel having a transmission channel H and a receiving channel V, S VV denotes an image of a quadrature polarimetric echo channel having a transmission channel V and a receiving channel V, S HL denotes an image of an echo channel having a transmission channel L and a receiving channel H for the modulated transmission signal, S HR denotes an image of an echo channel having a transmission channel R and a receiving channel H for the modulated transmission signal, S VL denotes an image of an echo channel having a transmission channel L and a receiving channel V for the modulated transmission signal, S VR denotes an image of an echo channel having a transmission channel R and a receiving channel V for the modulated transmission signal, L denotes an electromagnetic wave polarization manner of left circular polarization, R denotes an electromagnetic wave polarization manner of right circular polarization, H denotes an electromagnetic wave polarization manner of horizontal polarization, and V denotes an electromagnetic wave polarization manner of vertical polarization.
8. A device for suppressing range ambiguity, comprising:
a processor, and
a memory configured to store a computer program capable of running on the processor, wherein the processor, when the computer program runs thereon, executes operations of:
determining a pulse timing relationship of a transmission signal;
determining orthogonal nonlinear frequency modulation signals;
modulating the transmission signals by using the orthogonal nonlinear frequency modulation signals;
transmitting the modulated transmission signal according to the pulse timing relationship, and
determining echo data of the modulated transmission signal; and generating an image according to a polarization scattering matrix for the echo data of the modulated transmission signal,
wherein the processor, when the computer program runs thereon, further executes operations of:
determining a time-frequency relationship function of nonlinear frequency modulation signals according to a piecewise linear function, and determining a time domain function of the nonlinear frequency modulation signals according to the time-frequency relationship function;
determining a correlation performance parameter of the nonlinear frequency modulation signals according to the time domain function, and determining a mathematical model of the nonlinear frequency modulation signals according to the correlation performance parameter;
initializing the nonlinear frequency modulation signals according to pulse width and bandwidth settings of the nonlinear frequency modulation signals; and
performing iteration on the initialized nonlinear frequency modulation signals by using an augmented Lagrange algorithm according to the mathematical model to obtain the orthogonal nonlinear frequency modulation signals.
9. The device of claim 8 , wherein the processor, when the computer program runs thereon, further executes an operation of:
determining the pulse timing relationship of the transmission signal according to a pulse repetition frequency of the transmission signal, wherein the pulse timing relationship is represented as PRI=1/PRF, and PRF denotes the pulse repetition frequency of the transmission signal.
10. The device of claim 8 , wherein the transmission signal comprises a left circular polarization signal and a right circular polarization signal, and the processor, when the computer program runs thereon, further executes an operation of:
modulating the left circular polarization signal by using S 1 , and modulating the right circular polarization signal by using S 2 , S 1 and S 2 being the orthogonal nonlinear frequency modulation signals.
11. The device of claim 8 , wherein the processor, when the computer program runs thereon, further executes operations of:
transmitting the modulated transmission signal according to the pulse timing relationship and determining echo data of the modulated transmission signal comprises:
alternately transmitting the modulated transmission signal according to the pulse timing relationship; and
determining the echo data of the modulated transmission signal according to the pulse timing relationship and the polarization scattering matrix, the echo data of the modulated transmission signal being represented in a form of the polarization scattering matrix S CTLR
S
C
T
L
R
=
(
S
H
L
S
H
R
S
VL
S
VR
)
,
where,
S HL = +j ,( s 1 )
S HR = −j ,( s 2 )
S VL = +j ,( s 1 )
S VR = −j ,( s 2 ),
S HL denotes an echo of an echo channel having a transmission channel L and a receiving channel H for the modulated transmission signal, S HR denotes an echo of an echo channel having a transmission channel R and a receiving channel H for the modulated transmission signal, S VL denotes an echo of an echo channel having a transmission channel L and a receiving channel V for the modulated transmission signal, S VR denotes an echo of an echo channel having a transmission channel R and a receiving channel V for the modulated transmission signal, L denotes an electromagnetic wave polarization manner of left circular polarization, R denotes an electromagnetic wave polarization manner of right circular polarization, H denotes an electromagnetic wave polarization manner of horizontal polarization, and V denotes an electromagnetic wave polarization manner of vertical polarization.
12. The device of claim 11 , wherein the polarization scattering matrix S CTLR for the echo data of the transmission signal is represented as
S
C
T
L
R
=
(
S
H
L
S
H
R
S
VL
S
VR
)
,
where S HL denotes an echo of an echo channel having a transmission channel L and a receiving channel H, S HR denotes an echo of an echo channel having a transmission channel R and a receiving channel H, S VL denotes an echo of an echo channel having a transmission channel L and a receiving channel V, S VR denotes an echo of an echo channel having a transmission channel R and a receiving channel V, L denotes an electromagnetic wave polarization manner of left circular polarization, R denotes an electromagnetic wave polarization manner of right circular polarization, H denotes an electromagnetic wave polarization manner of horizontal polarization, and V denotes an electromagnetic wave polarization manner of vertical polarization.
13. The device of claim 11 , wherein the processor, when the computer program runs thereon, further executes operations of:
determining ground object scattering coefficients S HL S HR , S VL and S VR in the polarization scattering matrix S CTLR , where,
S HL = +j
S HR = −j
S VL = +j
S VR = −j ,
where , , and denote echoes of a linear polarimetric echo channel, denotes an echo of a linear polarimetric echo channel having a transmission channel H and a receiving channel H, denotes an echo of a linear polarimetric echo channel having a transmission channel V and a receiving channel H, denotes an echo of a linear polarimetric echo channel having a transmission channel H and a receiving channel V, denotes an echo of a linear polarimetric echo channel having a transmission channel V and a receiving channel V, L denotes an electromagnetic wave polarization manner of left circular polarization, R denotes an electromagnetic wave polarization manner of right circular polarization, H denotes an electromagnetic wave polarization manner of horizontal polarization, and V denotes an electromagnetic wave polarization manner of vertical polarization; and
obtaining the polarization scattering matrix for the echo data of the transmission signal according to the ground object scattering coefficients S HL , S HR , S VL and S VR .
14. The device of claim 8 , wherein the processor, when the computer program runs thereon, further executes operations of:
determining a quadruple polarimetric image of a hybrid polarimetric synthetic aperture radar (SAR) system according to the polarization scattering matrix for the echo data of the modulated transmission signal; and
determining a quadruple polarimetric image of a quadrature polarimetric SAR system according to the quadruple polarimetric image of the hybrid polarimetric SAR system,
wherein the quadruple polarimetric image of the quadrature polarimetric SAR system comprises:
S
H
H
=
1
2
·
(
S
H
L
+
S
H
R
)
S
H
V
=
1
2
j
·
(
S
H
L
-
S
H
R
)
S
V
H
=
1
2
·
(
S
V
L
+
S
V
R
)
S
VV
=
1
2
j
·
(
S
V
L
-
S
V
R
)
,
where S HH denotes an image of a quadrature polarimetric echo channel having a transmission channel H and a receiving channel H, S HV denotes an image of a quadrature polarimetric echo channel having a transmission channel V and a receiving channel H, S VH denotes an image of a quadrature polarimetric echo channel having a transmission channel H and a receiving channel V, S VV denotes an image of a quadrature polarimetric echo channel having a transmission channel V and a receiving channel V, S HL denotes an image of an echo channel having a transmission channel L and a receiving channel H for the modulated transmission signal, S HR denotes an image of an echo channel having a transmission channel R and a receiving channel H for the modulated transmission signal, S VL denotes an image of an echo channel having a transmission channel L and a receiving channel V for the modulated transmission signal, S VR denotes an image of an echo channel having a transmission channel R and a receiving channel V for the modulated transmission signal, L denotes an electromagnetic wave polarization manner of left circular polarization, R denotes an electromagnetic wave polarization manner of right circular polarization, H denotes an electromagnetic wave polarization manner of horizontal polarization, and V denotes an electromagnetic wave polarization manner of vertical polarization.
15. A non-transitory computer readable storage medium having stored thereon a computer program, wherein the computer program, when being executed by a processor, implements operations of:
determining a pulse timing relationship of a transmission signal;
determining orthogonal nonlinear frequency modulation signals;
modulating the transmission signals by using the orthogonal nonlinear frequency modulation signals;
transmitting the modulated transmission signal according to the pulse timing relationship, and determining echo data of the modulated transmission signal; and generating an image according to a polarization scattering matrix for the echo data of the modulated transmission signal,
wherein the computer program, when being executed by the processor, implements operations of:
determining a time-frequency relationship function of nonlinear frequency modulation signals according to a piecewise linear function, and determining a time domain function of the nonlinear frequency modulation signals according to the time-frequency relationship function;
determining a correlation performance parameter of the nonlinear frequency modulation signals according to the time domain function, and determining a mathematical model of the nonlinear frequency modulation signals according to the correlation performance parameter;
initializing the nonlinear frequency modulation signals according to pulse width and bandwidth settings of the nonlinear frequency modulation signals; and
performing iteration on the initialized nonlinear frequency modulation signals by using an augmented Lagrange algorithm according to the mathematical model to obtain the orthogonal nonlinear frequency modulation signals.
16. The non-transitory computer readable storage medium of claim 15 , wherein the computer program, when being executed by the processor, implements an operation of:
determining the pulse timing relationship of the transmission signal according to a pulse repetition frequency of the transmission signal, wherein the pulse timing relationship is represented as PRI=1/PRF, and PRF denotes the pulse repetition frequency of the transmission signal.
17. The non-transitory computer readable storage medium of claim 15 , wherein the transmission signal comprises a left circular polarization signal and a right circular polarization signal, and the computer program, when being executed by the processor, implements an operation of:
modulating the left circular polarization signal by using s 1 , and modulating the right circular polarization signal by using s 2 , s 1 and s 2 being the orthogonal nonlinear frequency modulation signals.