1. A design method of wave position parameters is applied to a satellite-borne SAR of a phased-array antenna, wherein the wave position parameters comprise the total number of wave positions, the central viewing angle of each wave position, the beam width of each wave position, the final near-end viewing angle and the final far-end viewing angle of each wave position, and the method comprises the following steps:

acquiring the total wave position number of the wave position to be designed;

determining the central view angle of each wave position according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna and the total number of the wave positions to be designed;

determining the beam width of each wave position according to the central visual angle of each wave position, the normal beam width of the phased array antenna and the normal visual angle of the phased array antenna;

and under the condition that the performance index of the satellite-borne SAR meets the preset condition, determining the final near-end visual angle and the final far-end visual angle of each wave position according to the central visual angle of each wave position.

2. The method of claim 1, wherein the obtaining a total number of wave bits to be designed comprises:

determining a minimum beam jump and a normal beam width of the phased array antenna;

determining a minimum central view and a maximum imaging view of the spaceborne SAR;

and determining the total wave position according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna, the maximum imaging view angle of the satellite-borne SAR and the normal beam width of the phased array antenna.

3. The method of claim 1, wherein the performance indicators of the spaceborne SAR comprise a data rate, an imaging bandwidth and a distance ambiguity, the preset conditions comprise a first condition, a second condition and a third condition, and the determining the final near-end view angle and the final far-end view angle of each wave position in case that the performance indicators of the spaceborne SAR meet the preset conditions comprises:

acquiring the data rate of the satellite-borne SAR;

under the condition that the data rate of the satellite-borne SAR meets the first condition, determining the imaging bandwidth of the satellite-borne SAR according to the initial far-end visual angle and the initial near-end visual angle of each wave position;

under the condition that the imaging bandwidth of the satellite-borne SAR meets the second condition, determining the distance ambiguity of the satellite-borne SAR according to the final pulse repetition frequency;

and under the condition that the range ambiguity of the satellite-borne SAR meets the third condition, determining a final near-end view angle and a final far-end view angle of each wave position.

4. The method of claim 3, wherein the obtaining the data rate of the on-board SAR comprises:

determining an initial near-end perspective and an initial far-end perspective of each of the wave positions;

determining a final pulse repetition frequency and a final pulse width of the spaceborne SAR according to the initial far-end visual angle and the initial near-end visual angle;

and determining the data rate of the satellite-borne SAR according to the initial near-end visual angle, the initial far-end visual angle, the final pulse repetition frequency of the satellite-borne SAR and the final pulse width of the satellite-borne SAR.

5. The method of claim 3, wherein the method further comprises:

determining a final near-end view angle and a final far-end view angle for each of the wave bits if the imaging bandwidth does not satisfy the second condition.

6. The method of claim 3, wherein the method further comprises:

under the condition that the data rate is determined not to meet the first condition, adjusting the initial far-end visual angle and the initial near-end visual angle, and re-determining a final pulse repetition frequency and a final pulse width of the satellite-borne SAR; or, under the condition that the distance ambiguity does not satisfy the third condition, adjusting the initial far-end view angle and the initial near-end view angle, and re-determining a final pulse repetition frequency and a final pulse width of the spaceborne SAR;

and determining the data rate of the spaceborne SAR according to the initial near-end visual angle, the initial far-end visual angle, the re-determined final pulse repetition frequency of the spaceborne SAR and the re-determined final pulse width of the spaceborne SAR.

7. The method of claim 4, wherein said determining an initial proximal perspective and an initial distal perspective for each of said wave sites comprises:

obtaining the beam width allowance of the wave position;

and determining an initial near-end visual angle and an initial far-end visual angle of each wave position according to the central visual angle of each wave position, the beam width of each wave position and the beam width allowance of each wave position.

8. The method of claim 7, wherein the determining a final pulse repetition frequency and a final pulse width of the on-board SAR from the initial far-end view angle and the initial near-end view angle comprises:

determining the initial pulse repetition frequency of the spaceborne SAR according to the strip mode azimuth ambiguity of the spaceborne SAR;

determining an initial duty cycle of the phased array antenna according to the maximum power consumption of the phased array antenna;

determining the initial pulse width of the satellite-borne SAR according to the initial pulse repetition frequency of the satellite-borne SAR and the initial duty ratio of the phased-array antenna;

determining the echo time of the satellite-borne SAR according to the initial pulse width of the satellite-borne SAR, the initial far-end visual angle of each wave position and the initial near-end visual angle of each wave position;

and under the condition that the echo time of the satellite-borne SAR can avoid the transmission window interference of the satellite-borne SAR and the sub-satellite point echo interference of the satellite-borne SAR, determining the final pulse repetition frequency and the final pulse width of the satellite-borne SAR.

9. The method of claim 8, wherein the method further comprises:

and under the condition that the echo time of the satellite-borne SAR cannot avoid the transmitting window interference of the satellite-borne SAR and the sub-satellite point echo interference of the satellite-borne SAR, adjusting the initial pulse repetition frequency and the initial duty ratio to obtain the redetermined initial pulse width.

10. A wave position parameter design device applied to a satellite-borne SAR of a phased-array antenna, wherein the wave position parameters comprise wave position total number, a central view angle of each wave position, a beam width of each wave position, a final near-end view angle and a final far-end view angle of each wave position, and the device comprises:

the acquisition module is used for acquiring the wave position total number of the wave positions to be designed;

a first determining module, configured to determine a central view angle of each wave position according to a minimum central view angle of the satellite-borne SAR, a minimum beam jump of the phased array antenna, and the total number of wave positions to be designed;

a second determining module, configured to determine a beam width of each wave position according to a central viewing angle of each wave position, a normal beam width of the phased array antenna, and a normal viewing angle of the phased array antenna;

and the third determining module is used for determining a final near-end visual angle and a final far-end visual angle of each wave position according to the central visual angle of each wave position under the condition that the performance index of the satellite-borne SAR meets the preset condition.

11. An electronic device comprising a memory and a processor, the memory storing a computer program operable on the processor, wherein the processor implements the steps of the method of any one of claims 1 to 9 when executing the program.

12. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 9.

Background

The existing satellite-borne Synthetic Aperture Radar (SAR) wave position design has the following problems:

the first problem is that the overlapping rate between wave positions is 10% to 50%, and in the case of selecting 1 wave position for imaging, the observation target is usually not in the center of the imaging band, and cannot image the target with the best performance, and sometimes the observation target may deviate from the imaging band, causing imaging failure.

The existing satellite-borne SAR wave position design adopts the design of a fixed imaging bandwidth, the wave beam of a small view angle wave position is generally widened greatly, the high-precision directional diagram modeling is not facilitated, the directional diagram measurement is needed, and the problem that the longer test time is needed under the condition that the number of the directional diagrams to be measured is large exists.

Problem three, although the wave level design of any pointing mode has more degrees of freedom, if the wave level design of any pointing mode is free, the problem that automatic design is difficult to realize exists, and the wave level design of any pointing mode needs to subversively modify the existing ground system, so that the imaging mode is not easy to realize as soon as possible.

Disclosure of Invention

In view of this, embodiments of the present application provide a method, an apparatus, a device, and a storage medium for designing a wave position parameter.

The technical scheme of the embodiment of the application is realized as follows:

in a first aspect, an embodiment of the present application provides a method for designing a wave position parameter, which is applied to a satellite-borne SAR of a phased array antenna, where the wave position parameter includes a total number of wave positions, a central view angle of each wave position, a beam width of each wave position, a final near-end view angle and a final far-end view angle of each wave position, and the method includes: acquiring the total wave position number of the wave position to be designed; determining the central view angle of each wave position according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna and the total number of the wave positions to be designed; determining the beam width of each wave position according to the central visual angle of each wave position, the normal beam width of the phased array antenna and the normal visual angle of the phased array antenna; and under the condition that the performance index of the satellite-borne SAR meets the preset condition, determining the final near-end visual angle and the final far-end visual angle of each wave position according to the central visual angle of each wave position.

In a second aspect, an embodiment of the present application provides a device for designing a wave position parameter, which is applied to a satellite-borne SAR of a phased array antenna, where the wave position parameter includes a total number of wave positions, a central view angle of each wave position, a beam width of each wave position, a final near-end view angle and a final far-end view angle of each wave position, and the device includes: the acquisition module is used for acquiring the wave position total number of the wave positions to be designed; a first determining module, configured to determine a central view angle of each wave position according to a minimum central view angle of the satellite-borne SAR, a minimum beam jump of the phased array antenna, and the total number of wave positions to be designed; a second determining module, configured to determine a beam width of each wave position according to a central viewing angle of each wave position, a normal beam width of the phased array antenna, and a normal viewing angle of the phased array antenna; and the third determining module is used for determining a final near-end visual angle and a final far-end visual angle of each wave position according to the central visual angle of each wave position under the condition that the performance index of the satellite-borne SAR meets the preset condition.

In a third aspect, an embodiment of the present application provides an electronic device, including: a memory storing a computer program operable on a processor and a processor implementing the steps of the method when executing the program.

In a fourth aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps in the method.

In the embodiment of the application, the total number of wave positions of the wave positions to be designed is firstly acquired, then the central view angle of each wave position is determined according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna and the total number of the wave positions to be designed, the beam width of each wave position is determined according to the central view angle of each wave position, the normal beam width of the phased array antenna and the normal view angle of the phased array antenna, and finally the final near-end view angle and the final far-end view angle of each wave position are determined under the condition that the performance index of the satellite-borne SAR meets the preset condition. Therefore, under the condition of designing the wave position, the wave position of which the central visual angle is closest to the visual angle corresponding to the target can be designed, the method ensures that the central visual angle difference of adjacent wave positions is minimum, the wave position parameters obtained by design improve the overlapping degree between the wave positions, is beneficial to placing the observation target in the center of an imaging band, can image the target with the best performance, and prevents the imaging failure caused by the fact that the observation target deviates from the imaging band.

In the embodiment of the application, the beam width of each wave position is determined according to the central viewing angle of each wave position, the normal beam width of the phased array antenna and the normal viewing angle of the phased array antenna, the design of non-fixed imaging bandwidth is adopted, the problem that the beam of a small-viewing-angle wave position is generally widened greatly, high-precision directional diagram modeling is not facilitated, directional diagram measurement needs to be carried out, and under the condition that the directional diagram to be measured is more, the problem that long testing time needs to be spent exists.

In the embodiment of the application, the provided wave position parameter design method can realize automatic design, and solves the problem that the automatic design is difficult to realize in the wave position design of any pointing mode; the wave position parameter design method provided by the application does not need subversive transformation on the existing ground system, and solves the problems that subversive transformation on the existing ground system is needed in wave position design of any pointing mode, and the imaging mode is not easy to realize as soon as possible.

Drawings

Fig. 1 is a schematic flow chart illustrating an implementation of a method for designing a wave position parameter according to an embodiment of the present disclosure;

fig. 2 is a flowchart of a method for designing a wave position of a satellite-borne SAR in an arbitrary pointing mode according to an embodiment of the present application;

fig. 3 is a schematic implementation flowchart of a method for designing a final near-end viewing angle and a final far-end viewing angle of a wave position according to an embodiment of the present disclosure;

fig. 4 is a schematic flow chart illustrating an implementation of a method for designing a final pulse repetition frequency and a final pulse width according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a design apparatus for wave position parameters according to an embodiment of the present disclosure;

fig. 6 is a schematic diagram of a hardware entity according to an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

It should be understood that the embodiments described herein are provided for explaining the technical solutions of the present application, and are not intended to limit the scope of the present application.

Fig. 1 is a schematic diagram of an implementation flow of a design method of a wave position parameter provided in an embodiment of the present application, and is applied to a satellite-borne SAR of a phased array antenna, where the wave position parameter includes a total number of wave positions, a central view angle of each wave position, a beam width of each wave position, a final near-end view angle and a final far-end view angle of each wave position, as shown in fig. 1, and includes:

s101, acquiring the total wave position number of the wave positions to be designed;

the space-borne SAR is an effective means for observing from space to the ground, has the advantages of all-time, all-weather and high resolution, can accurately survey and draw the terrain and the landform in detail, acquires the information of the earth surface and finally generates a high-resolution image of a target scene. A phased array antenna refers to an antenna that changes a pattern shape by controlling a feeding phase of a radiation element in an array antenna. With the development of antenna technology and radar technology, a large number of modern high-performance radars such as satellite-borne SAR adopt a phased array antenna system, and active phased array antennas are applied more and more widely and have higher and higher antenna performance.

The wave position refers to a position covered by a beam of the space-borne SAR at a certain angle in azimuth or elevation. The wave position is determined by five parameters of wave position total number, central visual angle, near visual angle, far-end visual angle and beam width. Wherein the wave position total number represents the total number of the position intervals covered by the satellite-borne SAR in the pitching direction.

Here, the total number of wave bits to be designed may be obtained according to parameters of the satellite-borne SAR and parameters of the phased array antenna.

Step S102, determining the central view angle of each wave position according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna and the total number of the wave positions to be designed;

to maximize the degree of overlap between multiple wave positions, the beam sweep step may be set equal to the minimum beam hop of the phased array antenna. The central view angle of each wave position is determined according to the wave beam scanning step. The central view angle of each of the wave positions may be determined, for example, using the following equation (1);

θ_c(k)＝θ_c，min+(k-1)·Δθ (1)；

wherein, theta_c(k) For the central view angle of each wave position, K is 1 to K, which is an integer, K is the total number of wave positions of the wave position to be designed, and c is the abbreviation of center; theta_c，minMin is a minimum central visual angle of the satellite-borne SAR, and min is short for a small (minor); Δ θ is the minimum beam jump of the phased array antenna.

Minimum central view angle theta of the spaceborne SAR_c，minCan be calculated by the following formula (2);

θ_c，min＝θ_norm-ceil((θ_norm-θ_min+BW_norm/2)/Δθ)×Δθ (2)；

wherein, theta_normIs the angle of view when the beam of the phased array antenna is not scanned, also called the normal angle of view, norm is short for normal (normal), theta_minIs the required minimum imaging viewing angle; delta theta is the wave beam scanning step, and in order to maximize the overlapping degree between wave positions, the wave beam scanning step is equal to the minimum wave beam jumping degree of the phased array antenna; ceil () is a round-up computation method.

BW_normFor normal antenna beam widthThe degree can be calculated by the following formula (3);

wherein, λ is the emission signal wavelength of the spaceborne SAR, H_antThe height of the phased array antenna is denoted by ant, which is called antenna (antenna) for short.

Step S103, determining the beam width of each wave position according to the central view angle of each wave position, the normal beam width of the phased array antenna and the normal view angle of the phased array antenna;

the beam width refers to the angle between two half-power points of the beam. In relation to the antenna gain, the larger the antenna gain, the narrower the beam.

In the implementation process, in order to fully utilize the gain of the phased array antenna to obtain high system sensitivity and facilitate high-precision directional diagram modeling, the beam width in the range direction is not widened, and the beam width of each wave position can be determined by using the following formula (4);

BW(k)＝BW_norm/cos(θ_c(k)-θ_norm) (4)；

wherein BW (k) is the beam width of each said wave bit; BW (Bandwidth)_normIs a normal beamwidth of the phased array antenna; theta_c(k) The central visual angle of each wave position; theta_normThe view angle at which the beam of the phased array antenna is not scanned is also referred to as the normal view angle.

And 104, under the condition that the performance index of the satellite-borne SAR meets the preset condition, determining the final near-end visual angle and the final far-end visual angle of each wave position according to the central visual angle of each wave position.

In some embodiments, the technical or performance indicators of the on-board SAR include echo time, duty cycle, data rate, bearing ambiguity, and range ambiguity. Wherein the echo time comprises an echo starting time and an echo ending time; duty cycle refers to the proportion of the power-on time relative to the total time within a pulse cycle; the data rate represents the number of bits of data information transmitted in one second, and the unit is bit/second (b/s); the ambiguity is expressed as the ratio of the fuzzy noise to the radar imaging echo signal; the azimuth ambiguity and the range ambiguity are one of important indexes for measuring the performance of a Synthetic Aperture Radar (SAR) system. The azimuth ambiguities are caused, among other things, by the side lobes of the antenna pattern and the azimuth limited sampling. The range ambiguity is a phenomenon that the quality of a satellite-borne SAR image is reduced because an echo of a surveying and mapping band and an echo of other scenes with integral pulse repetition periods difference reach a receiver at the same time, and the echo of the surveying and mapping band and an echo of a fuzzy area are mixed together. The performance indexes of the azimuth ambiguity and the distance ambiguity are accurately evaluated, the accurate prediction of the image quality which can be obtained by the satellite-borne SAR system is facilitated, and the method has important significance for optimizing the design of the satellite-borne SAR system.

And under the condition that the performance indexes meet preset conditions, determining the final near-end visual angle and the final far-end visual angle of each wave position.

In the embodiment of the application, the total number of wave positions of the wave positions to be designed is firstly acquired, then the central view angle of each wave position is determined according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna and the total number of the wave positions to be designed, the beam width of each wave position is determined according to the central view angle of each wave position, the normal beam width of the phased array antenna and the normal view angle of the phased array antenna, and finally the final near-end view angle and the final far-end view angle of each wave position are determined under the condition that the performance index of the satellite-borne SAR meets the preset condition. Therefore, the wave position parameters obtained by design improve the overlapping degree between the wave positions, are beneficial to placing the observation target in the center of the imaging belt, can image the target with the best performance, and prevent the observation target from deviating from the imaging belt to cause imaging failure.

In the embodiment of the application, the beam width of each wave position is determined according to the central viewing angle of each wave position, the normal beam width of the phased array antenna and the normal viewing angle of the phased array antenna, the design of non-fixed imaging bandwidth is adopted, the problem that the beam of a small-viewing-angle wave position is generally widened greatly, high-precision directional diagram modeling is not facilitated, directional diagram measurement needs to be carried out, and under the condition that the directional diagram to be measured is more, the problem that long testing time needs to be spent exists.

In the embodiment of the application, the provided wave position parameter design method can realize automatic design, and solves the problem that the automatic design is difficult to realize in the wave position design of any pointing mode; the wave position parameter design method provided by the application does not need subversive transformation on the existing ground system, and solves the problems that subversive transformation on the existing ground system is needed in wave position design of any pointing mode, and the imaging mode is not easy to realize as soon as possible.

The design method of the wave position parameter provided by the embodiment of the application is applied to a satellite-borne SAR of a phased array antenna, the wave position parameter comprises the total wave position number, the central view angle of each wave position, the beam width of each wave position, the final near-end view angle and the final far-end view angle of each wave position, the technical or performance index of the satellite-borne SAR comprises a data rate, an imaging bandwidth and a distance ambiguity, the preset condition comprises a first condition, a second condition and a third condition, and the design method comprises the following steps:

step S111, determining the minimum beam jump and the normal beam width of the phased array antenna;

in an implementation process, the minimum beam jump and the normal beam width of the phased array antenna can be determined according to the phased array antenna used by the satellite-borne SAR.

Step S112, determining a minimum central view angle and a maximum imaging view angle of the satellite-borne SAR;

in the implementation process, the minimum central view angle and the maximum imaging view angle of the spaceborne SAR are determined according to the system design of the spaceborne SAR.

Step S113, determining the total wave position according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna, the maximum imaging view angle of the satellite-borne SAR and the normal beam width of the phased array antenna;

in practice, the total number of wave bits K can be determined using the following equation (5);

wherein, theta_maxMax represents the maximum for the maximum imaging view angle of the spaceborne SAR; BW (Bandwidth)_normIs a normal beamwidth of the phased array antenna; theta_c,minIs the minimum central view angle of the spaceborne SAR; Δ θ is the minimum beam jump of the phased array antenna, min represents the minimum.

Step S114, determining the central view angle of each wave position according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna and the total number of the wave positions to be designed;

step S115, determining the beam width of each wave position according to the central view angle of each wave position, the normal beam width of the phased array antenna and the normal view angle of the phased array antenna;

step S116, acquiring the data rate of the satellite-borne SAR;

the data rate is one of the important technical indexes for describing a data transmission system, and refers to the speed of transmitting information on a communication line, and the number of bits transmitted in a unit time (usually one second).

In the implementation process, the data rate of the satellite-borne SAR can be determined according to the initial near-end view angle and the initial far-end view angle of the wave position and the parameters of the satellite-borne SAR.

In the implementation process, the data rate r of the satellite-borne SAR can be obtained by using the following formula (6);

wherein f is_sIs the sampling frequency, R_s,fIs the slope distance, R, corresponding to the initial far-end viewing angle_s,nIs the corresponding slant distance of the initial near-end visual angle, which is called slant (slant) for short, f is far (far) for short, n is near (near) for short, tau is the pulse width, n is_bIs the quantization bit number, C is the speed of light, b is the bit (bit), PRF is the pulse repetition frequency (pulse repetition)on frequency，PRF)。

Sampling frequency f_sThe value of (b) may be a frequency value which is greater than or equal to 1.2 times the bandwidth of the SAR received signal, and the bandwidth of the SAR received signal is calculated by the following formula (7);

where ρ is_gIs the ground distance resolution required by the satellite-borne SAR, g is ground (ground), eta for short_nIs the angle of incidence for the initial proximal viewing angle.

Step S117, under the condition that the data rate of the satellite-borne SAR meets the first condition, determining the imaging bandwidth of the satellite-borne SAR according to the initial far-end visual angle and the initial near-end visual angle of each wave position;

in an implementation process, a data rate threshold (data rate upper limit) of the satellite-borne SAR may be determined according to a data transmission link design scheme of the satellite-borne SAR, and then the first condition may be that the data rate of the satellite-borne SAR is smaller than the data rate threshold, that is, under the condition that the data rate of the satellite-borne SAR is determined to be smaller than the data rate threshold, the imaging bandwidth of the satellite-borne SAR is determined according to an initial far-end view angle and an initial near-end view angle of each wave position.

In the implementation process, the imaging bandwidth SW of the satellite-borne SAR can be calculated by using the following formula (8);

SW＝R_g，f-R_g，n (8)；

wherein R is_g,fIs the ground distance, R, corresponding to the initial far-end viewing angle_g,nIs the ground distance corresponding to the initial near-end perspective. Here, the ground distance refers to the ground distance, and the middle finger view angle in equation (8) corresponds to the distance from the ground position to the sub-satellite point.

Step S118, under the condition that the imaging bandwidth of the satellite-borne SAR meets the second condition, determining the distance ambiguity of the satellite-borne SAR according to the final pulse repetition frequency;

in the implementation process, an imaging bandwidth threshold (lower imaging bandwidth limit) of the satellite-borne SAR may be determined according to a design requirement of the satellite-borne SAR, and then the second condition may be that the imaging bandwidth of the satellite-borne SAR is greater than the imaging bandwidth threshold, that is, the distance ambiguity of the satellite-borne SAR is determined according to the final pulse repetition frequency under the condition that it is determined that the imaging bandwidth of the satellite-borne SAR is greater than the imaging bandwidth threshold.

In the implementation process, the range ambiguity RASR of the spaceborne SAR can be calculated by using the following formulas (9), (10), (11) and (12);

wherein j is 0.

Wherein j ≠ 0.

Wherein j is ± 1, ± 2, …, ± q.

Wherein, Sa_iAnd S_iRespectively the range ambiguity at the ith time point in the data window and the signal power,is the back-scattering coefficient of the light,is a two-way antenna pattern, R_ijIs the slant distance, eta_ijThe incidence angle is, q is the distance ambiguity zone number, the ambiguity zone number is determined according to the minimum slope distance which is the slope distance from SAR to the subsatellite point, and the maximum slope distance which is the slope distance tangent with the earth.

Step S119, under the condition that the range ambiguity of the satellite-borne SAR meets the third condition, determining a final near-end view angle and a final far-end view angle of each wave position.

In the implementation process, a distance ambiguity threshold value can be set according to actual needs, and then the third condition is that the distance ambiguity of the spaceborne SAR is smaller than the distance ambiguity threshold value, that is, under the condition that the distance ambiguity of the spaceborne SAR is smaller than the distance ambiguity threshold value, the final near-end view angle and the final far-end view angle of each wave position are determined.

In the embodiment of the application, under the condition that the data rate, the imaging bandwidth and the distance ambiguity of the satellite-borne SAR meet preset conditions, the final near-end visual angle and the final far-end visual angle of each wave position can be effectively determined.

The design method of the wave position parameter provided by the embodiment of the application is applied to a satellite-borne SAR of a phased array antenna, the wave position parameter comprises the total wave position number, the central view angle of each wave position, the beam width of each wave position, the final near-end view angle and the final far-end view angle of each wave position, the technical or performance index of the satellite-borne SAR comprises a data rate, an imaging bandwidth and a distance ambiguity, the preset condition comprises a first condition, a second condition and a third condition, and the design method comprises the following steps:

step S120, acquiring the total wave position number of the wave positions to be designed;

step S121, determining a central view angle of each wave position according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna and the total number of the wave positions to be designed;

step S123, determining the beam width of each wave position according to the central view angle of each wave position, the normal beam width of the phased array antenna and the normal view angle of the phased array antenna;

step S124, determining an initial near-end visual angle and an initial far-end visual angle of each wave position;

in practice, determining the initial proximal view and the initial distal view for each of the wave positions may include the steps of:

a1, obtaining the beam width margin of the wave position;

in practice, the beamwidth margin may be chosen to be twice the distance to beam pointing error. The range directional beam pointing error is determined according to the attitude error of the satellite-borne SAR and the pointing error of the phased array antenna.

And A2, determining an initial near-end visual angle and an initial far-end visual angle of each wave position according to the central visual angle of each wave position, the beam width of each wave position and the beam width margin of each wave position.

In practice, the initial near-end view angle and the initial far-end view angle of each wave position can be determined by using the following formulas (13) and (14);

θ_near(k)＝θ_c(k)-(BW-BW_margin)/2 (13)；

θ_far(k)＝θ_c(k)+(BW-BW_margin)/2 (14)；

wherein, BW_marginMargin of beam width and margin of margin.

Step S125, determining the final pulse repetition frequency and the final pulse width of the satellite-borne SAR according to the initial far-end visual angle and the initial near-end visual angle;

here, since the initial far-end view angle, the initial near-end view angle, and the final pulse width of the satellite-borne SAR may determine the echo time of the satellite-borne SAR, the final pulse width of the satellite-borne SAR is determined by the final pulse repetition frequency and the duty ratio, and the echo time of the satellite-borne SAR needs to be set to avoid transmission window interference and sub-satellite point echo interference, the final pulse repetition frequency and the final pulse width of the satellite-borne SAR need to be determined according to the initial far-end view angle and the initial near-end view angle. The final pulse repetition frequency and the final pulse width of the satellite-borne SAR are determined in detail, which can be seen in steps S141 to S146 below.

Step S126, determining the data rate of the satellite-borne SAR according to the initial near-end visual angle, the initial far-end visual angle, the final pulse repetition frequency of the satellite-borne SAR and the final pulse width of the satellite-borne SAR;

step S127, under the condition that the data rate of the satellite-borne SAR meets the first condition, determining the imaging bandwidth of the satellite-borne SAR according to the initial far-end view angle and the initial near-end view angle of each wave position;

step S128, under the condition that the data rate is determined not to meet the first condition, adjusting the initial far-end visual angle and the initial near-end visual angle, and re-determining the final pulse repetition frequency and the final pulse width of the satellite-borne SAR; determining the data rate of the spaceborne SAR again according to the initial near-end visual angle, the initial far-end visual angle, the re-determined final pulse repetition frequency of the spaceborne SAR and the re-determined final pulse width of the spaceborne SAR;

in the implementation, as in step S117 in the above embodiment, a data rate threshold (data rate upper limit) of the on-board SAR is determined, then the first condition may be that the data rate of the on-board SAR is smaller than the data rate threshold, that is, in a case that it is determined that the data rate of the on-board SAR is greater than the data rate threshold, the initial far-end view angle and the initial near-end view angle need to be adjusted. For example, the adjustment method may be: and adding the adjustment amount to the initial near-end visual angle to obtain an updated initial near-end visual angle, and subtracting the adjustment amount from the initial far-end visual angle to obtain an updated initial far-end visual angle, wherein the adjustment amount can be set according to actual needs.

Step S129, under the condition that the imaging bandwidth of the satellite-borne SAR meets the second condition, determining the range ambiguity of the satellite-borne SAR according to the final pulse repetition frequency;

step S130, determining a final near-end view angle and a final far-end view angle of each wave position when the imaging bandwidth does not satisfy the second condition;

in the implementation process, referring to step S118 in the above embodiment, an imaging bandwidth threshold (lower imaging bandwidth limit) of the satellite-borne SAR may be determined first, and the second condition may be that the imaging bandwidth of the satellite-borne SAR is greater than or equal to the imaging bandwidth threshold, and then the imaging bandwidth of the satellite-borne SAR is smaller than the imaging bandwidth threshold, that is, in the case that the imaging bandwidth of the satellite-borne SAR is determined to be smaller than the imaging bandwidth threshold, the final near-end view angle and the final far-end view angle of each of the wave positions may be determined, in this case, if the initial near-end view angle and the initial far-end view angle are continuously adjusted, the imaging bandwidth is difficult to meet the requirement, so that in the case that the imaging bandwidth and the distance ambiguity cannot be simultaneously met, the imaging bandwidth needs to be guaranteed first.

Step S131, determining a final near-end view angle and a final far-end view angle of each wave position under the condition that the distance ambiguity of the satellite-borne SAR meets the third condition;

step S132, under the condition that the distance ambiguity does not meet the third condition, adjusting the initial far-end view angle and the initial near-end view angle to re-determine the final pulse repetition frequency and the final pulse width of the satellite-borne SAR; and determining the data rate of the spaceborne SAR according to the initial near-end visual angle, the initial far-end visual angle, the re-determined final pulse repetition frequency of the spaceborne SAR and the re-determined final pulse width of the spaceborne SAR.

In the implementation process, referring to step S119 in the above embodiment, a distance ambiguity interval may be set according to actual needs, and then the third condition is that the distance ambiguity of the spaceborne SAR is in the set distance ambiguity interval, that is, under the condition that the distance ambiguity of the spaceborne SAR is not in the set distance ambiguity interval, the initial far-end view angle and the initial near-end view angle are adjusted to re-determine the final pulse repetition frequency and the final pulse width of the spaceborne SAR.

In the embodiment of the present application, in a case that the imaging bandwidth does not satisfy the second condition, a final near-end view angle and a final far-end view angle of each of the wave positions are determined. In this way, the final near-end viewing angle and the final far-end viewing angle of each wave position can be effectively obtained.

In this embodiment of the application, when it is determined that the data rate does not satisfy the first condition, or when the distance ambiguity does not satisfy the third condition, the initial far-end view and the initial near-end view are adjusted, and a final pulse repetition frequency and a final pulse width of the satellite-borne SAR are re-determined; and determining the data rate of the spaceborne SAR according to the initial near-end visual angle, the initial far-end visual angle, the re-determined final pulse repetition frequency of the spaceborne SAR and the re-determined final pulse width of the spaceborne SAR. In this way, the initial far-end viewing angle and the initial near-end viewing angle can be adjusted to obtain the final near-end viewing angle and the final far-end viewing angle of each wave position which meet the preset condition.

The embodiment of the application provides a method for determining a final pulse repetition frequency and a final pulse width of a satellite-borne SAR according to an initial far-end visual angle and an initial near-end visual angle, which comprises the following steps:

step S141, determining the initial pulse repetition frequency of the satellite-borne SAR according to the strip mode azimuth ambiguity of the satellite-borne SAR;

in implementation, the initial pulse repetition frequency of the on-board SAR may be determined to be a minimum pulse repetition frequency (PRFmin).

Determining PRFmin using the following equation (15) for calculating the band mode orientation ambiguity;

wherein m is an integer and represents the serial number of the fuzzy zone, the theoretical maximum value of m is infinity, and the influence of the first fuzzy zone is generally the maximum; f. of_dcIs the Doppler center frequency, Δ f_dcIs an estimated deviation of the Doppler Center frequency, and dc is an abbreviation of Doppler Center (Doppler Center); g_a(f) For directional antenna pattern, if the transmitting and receiving antenna patterns are different, the antenna pattern should be changedModified to G_T(T)*G_R(R), a is an antenna (antenna), T is a transmitting (transmit) short term, and R is a receiving (receiving) short term; PRF is pulse repetition frequency; b is_pFor the azimuth processing bandwidth, p is short for processing (processing), and the entire doppler bandwidth of the echo signal is not necessarily used in the processing, and a part may be filtered out.

In implementation, the maximum pulse repetition frequency (PRFmax) may be set at the same time, and PRFmax may be set to be 2 to 3 times of PRFmin.

Step S142, determining the initial duty ratio of the phased array antenna according to the maximum power consumption of the phased array antenna;

in implementation, a maximum duty cycle (DRmax) and a minimum duty cycle (DRmin) may be set, where the maximum duty cycle is mainly determined by the maximum power consumption of the phased array antenna, and the minimum duty cycle (DRmin) may be determined by the allowable system sensitivity drop (Δ NESZ) and the maximum duty cycle (DRmax), as shown in the following equation (16):

DR_min＝DR_max÷10^ΔNEsz/10 (16)；

where Δ NESZ is the amount of decrease in system sensitivity.

The initial duty cycle of the phased array antenna may then be set to the maximum duty cycle.

S143, determining the initial pulse width of the satellite-borne SAR according to the initial pulse repetition frequency of the satellite-borne SAR and the initial duty ratio of the phased-array antenna;

in implementation, the initial pulse width (τ) of the on-board SAR may be determined using equation (17) below;

initial pulse width (τ) is initial duty cycle/initial PRF (17).

Step S144, determining the echo time of the satellite-borne SAR according to the initial pulse width of the satellite-borne SAR, the initial far-end visual angle of each wave position and the initial near-end visual angle of each wave position;

in practice, the echo start time may be calculated using the following equation (18);

the echo end time can be calculated by the following formula (19);

wherein tau is the initial pulse width of the satellite-borne SAR, R_s，fSlope distance, R, corresponding to the initial far-end viewing angle_s，nThe slope distance corresponding to the initial proximal viewing angle.

Step S145, determining the final pulse repetition frequency and the final pulse width of the satellite-borne SAR under the condition that the echo time of the satellite-borne SAR can avoid the transmission window interference of the satellite-borne SAR and the off-satellite point echo interference of the satellite-borne SAR;

in the implementation process, the following formula (20) can be utilized to calculate and obtain the interference front echo time of the transmitting window of the satellite-borne SAR;

T_e1＝j·T_pri-τ-T_g (20)；

the following formulas (21) to (24) can be utilized to calculate and obtain the echo time calculation of the transmitting window interference back porch of the satellite-borne SAR;

T_e2＝j·T_pri+τ+T_g (21)；

j＝j_min，j_min+1，...，j_max (22)；

J_min＝int(T_min·PRF_min) (23)；

j_max＝int(T_far·PRF_max) (24)；

wherein, T_minAnd T_farRespectively corresponding echo time of a near-end visual angle and a far-end visual angle; t is_priIs a pulse repetition interval; t is_gIs the protection time, g is abbreviation of protection (guard); transmission window interference front echo time T of satellite-borne SAR_e1Interference back-porch echo time T of transmitting window of satellite-borne SAR_e2The corner mark e1 represents the transmit interference front edge and e2 represents the transmit interference back edge. e is shorthand for transmit (emit).

The leading edge time and the trailing edge time of the echo interference of the subsatellite point can be obtained by calculation by using the following formulas (25) and (26);

wherein h is the height of the satellite, the satellite refers to a satellite platform provided with an SAR, and the satellite-borne SAR refers to the SAR arranged on the satellite platform; i, i can be determined using the following equations (27) to (30)_min、i_maxAnd T_nad(ii) a nad is a shorthand for the subsatellite point (nadir), nad1 represents the subsatellite point echo leading edge, and nad2 represents the subsatellite point echo trailing edge.

i＝i_min，i_min+1，...，i_max (27)；

i_min＝j_min-int[(T_nad+τ+2T_g)·PRF_min] (28)；

i_max＝j_max-int(T_nad·PRF_max) (29)；

Wherein int in equation 28 is the rounding operation.

In the implementation process, whether the echo time of the satellite-borne SAR can avoid the transmission window interference of the satellite-borne SAR and the off-satellite point echo interference of the satellite-borne SAR is analyzed, and the final pulse repetition frequency and the final pulse width of the satellite-borne SAR are determined under the condition that the echo time can be avoided.

And step S146, under the condition that the echo time of the satellite-borne SAR cannot avoid the transmission window interference of the satellite-borne SAR and the satellite-borne point echo interference of the satellite-borne SAR, adjusting the initial pulse repetition frequency and the initial duty ratio to obtain the redetermined initial pulse width.

In practice, the initial pulse repetition frequency is adjusted by adding a set value to the initial pulse repetition frequency and re-determining the initial pulse repetition frequency until the initial pulse repetition frequency is equal to the maximum pulse repetition frequency. Under the condition that the initial pulse repetition frequency is equal to the maximum pulse repetition frequency, if the echo time of the satellite-borne SAR is determined to be incapable of avoiding the transmission window interference of the satellite-borne SAR and the satellite-borne point echo interference of the satellite-borne SAR, the initial duty ratio needs to be adjusted, the initial duty ratio can be reduced by a set value, the initial duty ratio is obtained again, and the initial pulse repetition frequency is reset to be equal to the minimum pulse repetition frequency. Obtaining a redetermined initial pulse width under the condition that the initial duty ratio is greater than or equal to the set minimum duty ratio; and resetting the maximum duty cycle, the minimum pulse repetition frequency and the maximum pulse repetition frequency when the initial duty cycle is smaller than the set minimum duty cycle.

In the embodiment of the application, according to the initial far-end view angle and the initial near-end view angle, under the condition that the echo time of the satellite-borne SAR can avoid the interference of a transmitting window of the satellite-borne SAR and the interference of an off-satellite point echo of the satellite-borne SAR, the final pulse repetition frequency and the final pulse width of the satellite-borne SAR are determined.

Fig. 2 is a flowchart of a method for designing a random directional mode wave position of a satellite-borne SAR according to an embodiment of the present application, and as shown in fig. 2, the method includes:

step S201, determining a central visual angle and the total number of wave positions of each wave position;

in implementation, the total number of wave bits may be determined with reference to steps S111 to S113 of the above embodiment; the central view angle of each wave position is determined with reference to step S102 of the above embodiment.

Step S202, determining the beam width of each wave position;

in implementation, the beam width of each wave position can be determined by referring to step S103 of the above embodiment

And step S203, determining a final near-end visual angle and a final far-end visual angle of each wave position.

In implementation, the final near-end view angle and the final far-end view angle of each wave position may be determined with reference to steps S116 to S119 of the above embodiment.

In the embodiment of the application, a method for designing the wave position of the satellite-borne SAR in any pointing mode based on the phased array antenna is provided, the central visual angle of the wave position is designed by taking the minimum beam jump degree of the phased array antenna as stepping, the near-end visual angle and the far-end visual angle of the wave position are selected by taking performance indexes as constraints, and the problem that an observation target is not located in the center of an imaging zone is solved.

Fig. 3 is a schematic implementation flowchart of a method for designing a final near-end viewing angle and a final far-end viewing angle of a wave position according to an embodiment of the present application, and as shown in fig. 3, the method includes:

s301, acquiring an initial near-end visual angle and an initial far-end visual angle;

in practice, reference may be made to steps a1 and a2 of the above example.

Step S302, determining the final pulse repetition frequency and the final pulse width;

in implementation, reference may be made to steps S141 to S146 of the above embodiment.

Step S303, determining whether the final pulse repetition frequency and the final pulse width are successfully obtained;

if the final pulse repetition frequency and the final pulse width are not successfully determined, go to step S304 to adjust the initial near-end view angle and the initial far-end view angle;

step S304, adjusting an initial near-end visual angle and an initial far-end visual angle;

step S305, acquiring a data rate;

in the case of successful determination of the final pulse repetition frequency and the final pulse width, the data rate is acquired.

Step S306, determining whether the data rate meets the constraint condition;

under the condition that the data rate is determined not to meet the constraint condition, the method goes to step S304 to adjust the initial near-end visual angle and the initial far-end visual angle; under the condition that the data rate is determined to meet the constraint condition, turning to step S307 to obtain the distance ambiguity and the imaging bandwidth;

step S307, obtaining distance ambiguity and imaging bandwidth;

step S308, determining whether the imaging bandwidth is larger than or equal to the minimum imaging bandwidth;

under the condition that the imaging bandwidth is determined to be smaller than the minimum imaging bandwidth, the process is turned to the step S310 and the process is ended; in the case where it is determined that the imaging bandwidth is equal to or greater than the minimum imaging bandwidth, it goes to step S309 to determine whether the distance ambiguity satisfies the index requirement.

Step S309, determining whether the distance ambiguity meets an index;

under the condition that the distance ambiguity is determined not to meet the index requirement, the step S304 is carried out to adjust the initial near-end visual angle and the initial far-end visual angle; in the case where it is determined that the distance ambiguity satisfies the index requirement, the flow proceeds to step S310.

And step S310, ending.

In the embodiment of the application, under the condition of meeting the data rate, the imaging bandwidth and the distance ambiguity, the final near-end visual angle and the final far-end visual angle of each wave position can be effectively determined.

Fig. 4 is a schematic flow chart of an implementation of a method for designing a final pulse repetition frequency and a final pulse width according to an embodiment of the present application, as shown in fig. 4, the method includes:

step S401, setting a minimum pulse repetition frequency, a maximum duty ratio and a minimum duty ratio, determining that an initial pulse repetition frequency is equal to the minimum pulse repetition frequency, and determining that the initial duty ratio is equal to the maximum duty ratio;

step S402, determining the pulse width according to the initial pulse repetition frequency and the initial duty ratio;

in implementation, reference may be made to equation (17) in step S143 of the above embodiment.

Step S403, determining whether the echo time can avoid the interference of a transmitting window and the echo interference of the off-satellite point;

in the implementation, reference may be made to step S145 in the above embodiment.

Under the condition that the echo time can avoid the interference of a transmitting window and the interference of the echo of the satellite point, the step S404 is carried out, and the final pulse repetition frequency and the final pulse width are determined; under the condition that the echo time can not avoid the interference of the transmitting window and the echo interference of the satellite points, turning to the step S405, and adjusting the initial pulse repetition frequency;

step S404, determining the final pulse repetition frequency and the final pulse width;

step S405, adjusting the initial pulse repetition frequency;

step S406, determining whether the initial pulse repetition frequency is less than or equal to the maximum pulse repetition frequency;

under the condition that the initial pulse repetition frequency is determined to be less than or equal to the maximum pulse repetition frequency, the step S402 is switched to determine the initial pulse repetition frequency again; in case it is determined that the initial pulse repetition frequency is greater than the maximum pulse repetition frequency, go to step S407, and reset the initial duty cycle.

Step S407, resetting the initial duty ratio and resetting the initial pulse repetition frequency to be equal to the minimum pulse repetition frequency;

in implementation, reference may be made to step S146 of the above embodiment.

Step S408, determining whether the reset initial duty ratio is larger than or equal to the minimum duty ratio;

and when the reset initial duty ratio is determined to be larger than or equal to the minimum duty ratio, the step S402 is switched to determine the initial pulse repetition frequency and the initial pulse width again, and when the reset initial duty ratio is determined to be smaller than the minimum duty ratio, the step S401 is switched to reset the maximum duty ratio, the minimum pulse repetition frequency and the maximum pulse repetition frequency.

In the embodiment of the application, according to the initial far-end view angle and the initial near-end view angle, under the condition that the echo time of the satellite-borne SAR can avoid the interference of a transmitting window of the satellite-borne SAR and the interference of an off-satellite point echo of the satellite-borne SAR, the final pulse repetition frequency and the final pulse width of the satellite-borne SAR are determined.

Based on the foregoing embodiments, the present application provides a wave position parameter design apparatus, which includes modules and sub-modules included in the modules, and can be implemented by a processor in a wave position design device; of course, it may also be implemented by logic circuitry; in implementation, the processor may be a Central Processing Unit (CPU), a Microprocessor (MPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), or the like.

Fig. 5 is a schematic structural diagram of a device for designing a wave position parameter according to an embodiment of the present application, and as shown in fig. 5, the device 500 includes:

an obtaining module 501, configured to obtain a total number of wave bits of a wave bit to be designed;

a first determining module 502, configured to determine a central view angle of each wave position according to a minimum central view angle of the space-borne SAR, a minimum beam jump of the phased array antenna, and the total number of wave positions to be designed;

a second determining module 503, configured to determine a beam width of each wave position according to a central viewing angle of each wave position, a normal beam width of the phased array antenna, and a normal viewing angle of the phased array antenna;

a third determining module 504, configured to determine, according to the central view angle of each wave position, a final near-end view angle and a final far-end view angle of each wave position under the condition that it is determined that the performance index of the satellite-borne SAR satisfies a preset condition.

In some embodiments, the obtaining module 501 includes a first determining submodule, a second determining submodule, and a third determining submodule, wherein the first determining submodule is configured to determine a minimum beam jump and a normal beam width of the phased array antenna; the second determining submodule is used for determining a minimum central view angle and a maximum imaging view angle of the satellite-borne SAR; the third determining submodule is used for determining the total wave position according to the minimum central view angle of the satellite-borne SAR, the minimum beam jump degree of the phased array antenna, the maximum imaging view angle of the satellite-borne SAR and the normal beam width of the phased array antenna.

In some embodiments, the performance index of the spaceborne SAR includes a data rate, an imaging bandwidth and a distance ambiguity, the preset condition includes a first condition, a second condition and a third condition, the third determining module 504 includes an obtaining sub-module, a fourth determining sub-module, a fifth determining sub-module and a sixth determining sub-module, wherein the obtaining sub-module is configured to obtain the data rate of the spaceborne SAR; the fourth determining submodule is used for determining the imaging bandwidth of the satellite-borne SAR according to the initial far-end visual angle and the initial near-end visual angle of each wave position under the condition that the data rate of the satellite-borne SAR meets the first condition; the fifth determining submodule is used for determining the distance ambiguity of the satellite-borne SAR according to the final pulse repetition frequency under the condition that the imaging bandwidth of the satellite-borne SAR meets the second condition; the sixth determining submodule is configured to determine a final near-end view and a final far-end view of each wave position when the range ambiguity of the satellite-borne SAR satisfies the third condition.

In some embodiments, the acquisition sub-module comprises a first determination unit, a second determination unit and a third determination unit, wherein the first determination unit is configured to determine an initial near-end view angle and an initial far-end view angle of each wave position; the second determining unit is configured to determine a final pulse repetition frequency and a final pulse width of the satellite-borne SAR according to the initial far-end view and the initial near-end view; the third determining unit is configured to determine a data rate of the spaceborne SAR according to the initial near-end view angle, the initial far-end view angle, a final pulse repetition frequency of the spaceborne SAR, and a final pulse width of the spaceborne SAR.

In some embodiments, the third determining module 504 further comprises a seventh determining sub-module for determining a final near-end view angle and a final far-end view angle for each of the wave positions if the imaging bandwidth does not satisfy the second condition.

In some embodiments, the third determination module 504 further includes a first re-determination sub-module and a second re-determination sub-module, wherein the first re-determination sub-module is configured to, if it is determined that the data rate does not satisfy the first condition, adjust the initial far-end view angle and the initial near-end view angle, and re-determine a final pulse repetition frequency and a final pulse width of the on-board SAR; or, under the condition that the distance ambiguity does not satisfy the third condition, adjusting the initial far-end view angle and the initial near-end view angle, and re-determining a final pulse repetition frequency and a final pulse width of the spaceborne SAR; and the final re-determination submodule is used for re-determining the data rate of the satellite-borne SAR according to the initial near-end visual angle, the initial far-end visual angle, the re-determined final pulse repetition frequency of the satellite-borne SAR and the re-determined final pulse width of the satellite-borne SAR.

In some embodiments, the first determining unit includes an obtaining subunit and a first determining subunit, wherein the obtaining subunit is configured to obtain a beam width margin of the wave position; the determining subunit is configured to determine an initial near-end view angle and an initial far-end view angle of each wave position according to the central view angle of each wave position, the beam width of each wave position, and the beam width margin of the wave position.

In some embodiments, the second determining unit includes a second determining subunit, a third determining subunit, a fourth determining subunit, a fifth determining subunit, and a sixth determining subunit, where the second determining subunit is configured to determine an initial pulse repetition frequency of the on-board SAR according to a strip-mode azimuth ambiguity of the on-board SAR; the third determining subunit is configured to determine an initial duty cycle of the phased array antenna according to a maximum power consumption of the phased array antenna; the fourth determining subunit is configured to determine an initial pulse width of the satellite-borne SAR according to an initial pulse repetition frequency of the satellite-borne SAR and an initial duty cycle of the phased-array antenna; the fifth determining subunit is configured to determine an echo time of the satellite-borne SAR according to an initial pulse width of the satellite-borne SAR, an initial far-end view angle of each wave position, and an initial near-end view angle of each wave position; the sixth determining subunit is configured to determine a final pulse repetition frequency and a final pulse width of the satellite-borne SAR when it is determined that the echo time of the satellite-borne SAR can avoid the transmission window interference of the satellite-borne SAR and the satellite-based point echo interference of the satellite-borne SAR.

In some embodiments, the second determining unit further includes a re-determining subunit, configured to, when it is determined that the echo time of the on-board SAR cannot avoid the transmission window interference of the on-board SAR and the sub-satellite point echo interference of the on-board SAR, adjust the initial pulse repetition frequency and the initial duty cycle to obtain a re-determined initial pulse width.

The above description of the apparatus embodiments, similar to the above description of the method embodiments, has similar beneficial effects as the method embodiments. For technical details not disclosed in the embodiments of the apparatus of the present application, reference is made to the description of the embodiments of the method of the present application for understanding.

It should be noted that, in the embodiment of the present application, if the method of wave bit design described above is implemented in the form of a software functional module and sold or used as a standalone product, it may also be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing an imaging device to execute all or part of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read Only Memory (ROM), a magnetic disk, or an optical disk. Thus, embodiments of the present application are not limited to any specific combination of hardware and software.

Correspondingly, an embodiment of the present application provides an electronic device, and fig. 6 is a schematic diagram of a hardware entity provided in the embodiment of the present application, and as shown in fig. 6, the hardware entity of the device 600 includes: comprising a memory 601 and a processor 602, said memory 601 storing a computer program operable on the processor 602, said processor 602 implementing the steps in the methods provided in the embodiments described above when executing said program.

The Memory 601 is configured to store instructions and applications executable by the processor 602, and may also buffer data (e.g., image data, audio data, voice communication data, and video communication data) to be processed or already processed by the processor 602 and modules in the device 600, and may be implemented by a FLASH Memory (FLASH) or a Random Access Memory (RAM).

Embodiments of the present application provide a computer-readable storage medium, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps in the above method.

Here, it should be noted that: the above description of the storage medium and device embodiments is similar to the description of the method embodiments above, with similar advantageous effects as the method embodiments. For technical details not disclosed in the embodiments of the storage medium and apparatus of the present application, reference is made to the description of the embodiments of the method of the present application for understanding.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.

Those of ordinary skill in the art will understand that: all or part of the steps for realizing the method embodiments can be completed by hardware related to program instructions, the program can be stored in a computer readable storage medium, and the program executes the steps comprising the method embodiments when executed; and the aforementioned storage medium includes: various media that can store program codes, such as a removable Memory device, a Read Only Memory (ROM), a magnetic disk, or an optical disk. Alternatively, the integrated units described above in the present application may be stored in a computer-readable storage medium if they are implemented in the form of software functional modules and sold or used as independent products. Based on such understanding, the technical solutions of the embodiments of the present application may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a device to perform all or part of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a removable storage device, a ROM, a magnetic or optical disk, or other various media that can store program code.

The above description is only for the embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.