Antenna parameter design method of synthetic aperture radiometer and synthetic aperture radiometer

Abstract

The invention discloses an antenna parameter design method of a synthetic aperture radiometer and the synthetic aperture radiometer, and belongs to the technical field of synthetic aperture radiometers. Wherein an antenna array in the synthetic aperture radiometer is used for uniformly sampling an observation target on a spatial frequency; each antenna in the antenna array is a sub-array antenna; the antenna parameter design method comprises the step of matching the zero point position of a sub-array antenna pattern with the grating lobe position of an array factor of an antenna array to obtain the antenna parameter of the synthetic aperture radiometer. According to the method, the number of subsequent receiving channels and correlators does not need to be increased, the sampling interval of a spatial frequency domain does not need to be changed, the spatial frequency sampling period is not shortened, meanwhile, the original signal processing flow of the aperture radiometer is not affected, and grating lobes can be suppressed on the premise that the system complexity, accuracy, angular resolution and calculation efficiency are not sacrificed.

Description

Technical Field

[0001] The present invention belongs to the technical field of synthetic aperture radiometers, and more specifically, relates to a method for designing antenna parameters of a synthetic aperture radiometer and a synthetic aperture radiometer. Background Art

[0002] Synthetic Aperture Interferometric Radiometer (SAIR) has the capabilities of instantaneous imaging, passive observation, and all-weather operation. These advantages have enabled it to be widely used in recent years in fields such as remote sensing and earth observation, climate and weather research, agriculture, and target detection. However, due to the trade-off between resolution and system complexity, synthetic aperture interferometric radiometer systems often do not meet the Nyquist sampling criterion, so they need to perform sparse sampling in the spatial frequency domain, but this will cause grating lobes to appear in the array factor, which in turn leads to spatial grating lobes and aliasing artifacts in the imaging results.

[0003] By designing a suitable antenna array, grating lobes can be reduced or suppressed. However, this is a challenging task because in most SAIR applications, in order to balance performance and system complexity, the minimum element spacing is often greater than half of the wavelength and cannot meet the Nyquist sampling law. To address the above problems, some researchers have additionally added three smaller antennas, each with a diameter half that of the larger antenna, to achieve the required minimum baseline, but this method still requires further increasing the number of subsequent receiving channels and correlators, resulting in a high system complexity. There is also work that changes the sampling interval in the spatial frequency domain by interpolating the spatial frequency without changing the antenna spacing, but this method will result in a higher inversion error for the system. In addition, some researchers have introduced a linear array with a smaller spatial frequency sampling period, effectively doubling the aliasing-free field of view and thus reducing the number of grating lobes, but this method will reduce the angular resolution of the system. Some researchers have also started from the perspective of signal processing and proposed an adaptive sidelobe suppression method, but this method has a large computational cost and low computational efficiency. These methods mainly reduce the impact of grating lobes or sidelobes by optimizing the array layout and imaging algorithms, but at the cost of sacrificing system complexity, accuracy, angular resolution, or computational efficiency. Summary of the Invention

[0004] Aiming at the above defects or improvement requirements of the prior art, the present invention provides a method for designing antenna parameters of a synthetic aperture radiometer and a synthetic aperture radiometer, aiming to suppress grating lobes without sacrificing system complexity, accuracy, resolution, and computational efficiency.

[0005] To achieve the above object, in a first aspect, the present invention provides a method for designing antenna parameters of a synthetic aperture radiometer; wherein, the antenna array in the synthetic aperture radiometer is used to uniformly sample the observation target in spatial frequency; each antenna in the antenna array is a sub-array antenna; the sub-array antenna includes: antenna elements arranged in N rows and M columns; both N and M are positive integers.

[0006] The method for designing antenna parameters includes: matching the zero position of the sub-array antenna pattern with the grating lobe position of the antenna array factor to obtain the antenna parameters of the synthetic aperture radiometer.

[0007] Further preferably, the above antenna parameters include: the spacing between sub-array antennas in the antenna array, the number of rows N, the number of columns M, and the spacing between antenna elements in the sub-array antenna.

[0008] The above method for designing antenna parameters includes:

[0009] Setting the spacing between sub-array antennas, the number of rows N, and the number of columns M in the antenna array to corresponding preset values respectively;

[0010] Setting the value of the array factor of the sub-array antenna at the position of (ξ g1 , η g1 ) to 0, so that the zero position of the sub-array antenna pattern matches the grating lobe position of the antenna array factor closest to the main lobe, and obtaining the spacing between antenna elements in the sub-array antenna; where (ξ g1 , η g1 ) is the grating lobe position of the antenna array factor closest to the main lobe.

[0011] Further preferably, the expression of the array factor of the sub-array antenna is:

[0012]

[0013] where (ξ, η) is an arbitrary position in the field of view coordinate system of the synthetic aperture radiometer; θ and respectively represent the elevation angle and azimuth angle when the antenna array observes the position of (ξ, η); d sx and d sy are respectively the antenna spacings of the antenna elements in the sub-array antenna in the x-axis direction and y-axis direction in the xy coordinate system where the antenna array is located; the x-axis direction of the xy coordinate system where the antenna array is located is parallel to the row direction of the sub-array antenna, and the y-axis direction is parallel to the column direction of the sub-array antenna.

[0014] Further preferably, ξ g1 and η g1 are respectively:

[0015]

[0016] where k u1 is 1 or -1; k u1 is 1 or -1; (ξ 0 , η 0 ) is the main lobe position of the antenna array array factor; Δu and Δv are respectively the minimum sampling baselines of the sub-array antennas in the x-axis direction and the y-axis direction in the xy coordinate system where the antenna array is located; d x and d y are respectively the spacings of the sub-array antennas in the x-axis direction and the y-axis direction in the xy coordinate system where the antenna array is located; λ is the wavelength corresponding to the operating frequency of the synthetic aperture interferometric radiometer.

[0017] Further preferably, in the xy coordinate system where the antenna array is located, the antenna spacing of the antenna elements in the sub-array antenna in the x-axis direction and the antenna spacing in the y-axis direction

[0018] Further preferably, the above antenna parameter design method further includes: after obtaining the spacings of the antenna elements in the sub-array antenna, taking the value of the array factor of the sub-array antenna at any grating lobe position of the antenna array array factor equal to 0 as the target, and adjusting the sub-array antenna spacing, the number of rows N, and / or the number of columns M in the antenna array.

[0019] In a second aspect, the present invention provides a synthetic aperture radiometer, in which the antenna array therein is used to uniformly sample the observation target in spatial frequency; each antenna in the antenna array is a sub-array antenna; the sub-array antenna includes: antenna elements arranged in N rows and M columns; both N and M are positive integers;

[0020] The antenna parameters of the synthetic aperture radiometer are designed by the antenna parameter design method provided in the first aspect of the present invention.

[0021] In a third aspect, the present invention provides an electronic device, including: a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, it executes the antenna parameter design method provided in the first aspect of the present invention.

[0022] In a fourth aspect, the present invention further provides a computer-readable storage medium, the computer-readable storage medium includes a stored computer program, wherein when the computer program is run by a processor, it controls the device where the storage medium is located to execute the antenna parameter design method provided in the first aspect of the present invention.

[0023] In a fifth aspect, the invention further provides a computer program product, including computer program / instructions, and when the computer program / instructions are executed by a processor, they implement the antenna parameter design method provided in the first aspect of the present invention.

[0024] Generally speaking, through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:

[0025] 1. The present invention provides a synthetic aperture radiometer and its antenna parameter design method. The traditional antenna in the traditional synthetic aperture radiometer is replaced with a sub-array antenna. On this basis, the antenna parameters of the synthetic aperture radiometer are designed so that the zero position of the sub-array antenna pattern matches the grating lobe position of the antenna array array factor; the present invention does not need to increase the number of subsequent receiving channels and correlators, nor does it need to change the sampling interval in the spatial frequency domain, nor does it reduce the spatial frequency sampling period, and at the same time does not affect the original signal processing flow of the aperture radiometer, and can suppress grating lobes without sacrificing system complexity, accuracy, angular resolution and computational efficiency.

[0026] 2. Further, in the synthetic aperture radiometer and its antenna parameter design method provided by the present invention, since the grating lobe closest to the main lobe has a greater impact on the imaging result compared to other grating lobes, therefore, the grating lobe closest to the main lobe of the antenna array array factor is preferentially suppressed. By setting the value of the array factor of the sub-array antenna to 0 at the position of the grating lobe closest to the main lobe of the antenna array array factor, the spacing between antenna elements in the sub-array antenna can be calculated, which can further reduce the computational complexity in the design process.

[0027] 3. Further, in the synthetic aperture radiometer and its antenna parameter design method provided by the present invention, after obtaining the spacing between antenna elements in the sub-array antenna, the spacing between sub-array antennas, the number of rows N and / or the number of columns M in the antenna array are further adjusted so that the value of the array factor of the sub-array antenna at any grating lobe position of the antenna array array factor is equal to 0, thereby further improving the suppression effect of grating lobes. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the working process of the synthetic aperture interferometric radiometer provided by an embodiment of the present invention;

[0029] Figure 2 It is a schematic diagram of the arrangement of the antenna array in the synthetic aperture radiometer provided by an embodiment of the present invention;

[0030] Figure 3 It is a schematic diagram of the traditional antenna provided by an embodiment of the present invention;

[0031] Figure 4 It is a schematic diagram of the sub-array antenna provided by an embodiment of the present invention;

[0032] Figure 5Schematic diagram of the pattern simulation results of the traditional antenna and the sub-array antenna provided by the embodiments of the present invention; wherein, (a) is the pattern of the traditional antenna; (b) is the pattern of the sub-array antenna; (c) is the cross-sectional comparison diagram of the patterns of the traditional antenna and the sub-array antenna when η = 0; (d) is the cross-sectional comparison diagram of the patterns of the traditional antenna and the sub-array antenna when ξ = 0;

[0033] Figure 6 Patterns of the traditional antenna array and the sub-array antenna array provided by the embodiments of the present invention and cross-sectional comparison diagrams of the two; wherein, (a) is the pattern of the traditional antenna array; (b) is the pattern of the sub-array antenna array; (c) is the cross-sectional comparison diagram of the patterns of the traditional antenna array and the sub-array antenna array when η = 0; (d) is the cross-sectional comparison diagram of the patterns of the traditional antenna array and the sub-array antenna array when ξ = 0;

[0034] Figure 7 Original brightness temperature distribution and corresponding imaging results when there is a target at or near the grating lobe provided by the embodiments of the present invention; wherein, (a) is the original brightness temperature distribution when there is a target at or near the grating lobe; (b) is the imaging result of the synthetic aperture radiometer based on the traditional array; (c) is the imaging result of the synthetic aperture radiometer based on the sub-array array; (d) is the cross-sectional comparison diagram of the original brightness temperature distribution, the imaging result of the synthetic aperture radiometer based on the traditional array, and the imaging result of the synthetic aperture radiometer based on the sub-array array when η = 0;

[0035] Figure 8 Original brightness temperature distribution and corresponding imaging results when there are multiple targets in the scenario provided by the embodiments of the present invention; wherein, (a) is the original brightness temperature distribution when there are multiple targets at or near the grating lobe; (b) is the imaging result of the synthetic aperture radiometer based on the traditional array; (c) is the imaging result of the synthetic aperture radiometer based on the sub-array array; (d) is the cross-sectional comparison diagram of the original brightness temperature distribution, the imaging result of the synthetic aperture radiometer based on the traditional array, and the imaging result of the synthetic aperture radiometer based on the sub-array array when η = 0. Detailed implementation manners

[0036] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] In order to achieve the above objectives, in a first aspect, the present invention provides a method for designing antenna parameters of a synthetic aperture radiometer.

[0038] The synthetic aperture interferometric radiometer consists of multiple antennas distributed at different positions. As Figure 1 shown, by performing complex correlation on the signals received by the antennas, the visibility function corresponding to different baselines can be obtained in the spatial frequency domain; then, using an inversion algorithm to process these visibility samples, an estimated value of the brightness temperature distribution of the observed scene can be obtained.

[0039] In the synthetic aperture interferometric radiometer system, under far-field conditions, the visibility function V(u ij ,v ij ) and the brightness temperature distribution T(ξ,η) satisfy the following relationship:

[0040]

[0041] where T m (ξ,η) is the corrected brightness temperature distribution; is the spatial frequency, specifically the wavelength-normalized interval between the i-th antenna and the j-th antenna; (x i ,y i ) are the Cartesian coordinates of the i-th antenna; λ is the wavelength corresponding to the operating frequency of the synthetic aperture interferometric radiometer; represents the direction cosine, θ and represent the elevation angle and azimuth angle in the spherical coordinate system respectively; Ω is the equivalent solid angle of the antenna; f(ξ,η) is the normalized antenna pattern; is the fringe-nulling function; is the tilt factor.

[0042] In actual calculations, it is usually assumed that and r ij ≈1. According to Equation (1), the relationship between the estimated corrected brightness temperature distribution and the actual corrected brightness temperature distribution is:

[0043]

[0044] Substituting Equation (2) into Equation (3), we can obtain:

[0045]

[0046] where AF(ξ-ξ',η-η') is the array factor of the antenna array.

[0047] It can be seen from Equation (5) that the influence of the antenna array on the performance of the synthetic aperture interferometric radiometer system is jointly determined by the array arrangement and the element antennas.

[0048] From the perspective of unit antenna design, the present invention calculates the grating lobe positions of the array factor of the antenna array according to the antenna array structure, and designs a sub-array antenna to replace the traditional unit antenna, so that the null positions of the sub-array antenna pattern match the grating lobe positions, thereby suppressing the array grating lobes without increasing the system complexity and calculation cost, and maintaining the performance such as resolution, sensitivity, and accuracy of the synthetic aperture interferometric radiometer.

[0049] Specifically, the antenna array in the synthetic aperture radiometer of the present invention is used to uniformly sample the observation target in spatial frequency; each antenna in the antenna array is a sub-array antenna; the sub-array antenna includes: antenna elements arranged in N rows and M columns; both N and M are positive integers; and the sub-array antennas in the antenna array are all the same.

[0050] The antenna parameter design method includes: obtaining the antenna parameters of the synthetic aperture radiometer by matching the null positions of the sub-array antenna pattern with the grating lobe positions of the array factor of the antenna array; wherein, the antenna parameters include: the spacing between sub-array antennas in the antenna array, the number of rows N, the number of columns M, and the spacing between antenna elements in the sub-array antenna.

[0051] The calculation formula of the sub-array antenna pattern is as follows:

[0052]

[0053] Among them, the first term is the array factor of the sub-array antenna, and the second term f n (ξ) is the pattern of the antenna element in the sub-array antenna. The array factor of the sub-array antenna can be rewritten as:

[0054]

[0055] where (ξ,η) is an arbitrary position in the field of view coordinate system of the synthetic aperture radiometer; θ and respectively represent the elevation angle and azimuth angle when the antenna array observes the position (ξ,η); d sx and d sy are respectively the antenna spacings of the antenna elements in the sub-array antenna in the x-axis direction and y-axis direction in the xy coordinate system where the antenna array is located; the x-axis direction of the xy coordinate system where the antenna array is located is parallel to the row direction of the sub-array antenna, and the y-axis direction is parallel to the column direction of the sub-array antenna.

[0056] If the grating lobes are to be suppressed, the nulls of the array factor of the sub-array antenna should match the grating lobes (ξ g ,η g ) of the array factor of the antenna array, that is, the following equation needs to be satisfied:

[0057]

[0058] It should be noted that there are various arrangements of the antenna array, which can be arranged in a rectangular, Y-shaped, hexagonal or other shapes, as long as it satisfies that the antenna array uniformly samples the observation target in spatial frequency, and no limitation is made here. Preferably, the antenna array is rectangular. At this time, the antenna array is rectangular, and the sub-array antennas are distributed on the sides of the rectangle.

[0059] In the xy coordinate system where the antenna array is located, the spacings of the sub-array antennas in the x-axis direction and the y-axis direction are respectively denoted as d x and d y , and the corresponding minimum sampling baselines (minimum sampling intervals) are respectively Δu and Δv, which are expressed as: Then the grating lobe positions of the antenna array factor are:

[0060]

[0061] where (ξ 0 , η 0 ) is the main lobe position of the antenna array factor; represents rounding down.

[0062] Since the grating lobe closest to the main lobe has a greater impact on the imaging result compared to other grating lobes, preferably, in an alternative embodiment, the grating lobe closest to the main lobe of the antenna array factor is preferentially suppressed, and the corresponding grating lobe positions (ξ g1 , η g1 ) are when k u = ±1, and (ξ g1 , η g1 ) when k v = ±1; specifically, k u1 is 1 or -1; k u1 is 1 or -1.

[0063] At this time, the spacing between the antenna elements in the above sub-array antenna is calculated as follows:

[0064] Set the spacing, number of rows N, and number of columns M of the sub-array antennas in the antenna array to the corresponding preset values; in this embodiment, they are all set to the corresponding empirical values, and preferably ensure that the number of antenna elements in the sub-array antenna is as small as possible;

[0065] By making the array factor of the sub-array antenna at (ξ g1 , η g1The value at the position is set to 0 to achieve the matching between the null position of the sub-array antenna pattern and the grating lobe position closest to the main lobe of the antenna array factor, and thus the spacing between the antenna elements within the sub-array antenna is calculated. Specifically, in the xy coordinate system where the antenna array is located, the antenna spacing of the antenna elements in the sub-array antenna in the x-axis direction The antenna spacing in the y-axis direction wherein both the sub-array antenna spacing and the number of antenna elements in the sub-array antenna are empirically set values that are preset.

[0066] Preferably, in an alternative embodiment, on the premise of ensuring that the grating lobe closest to the main lobe is effectively suppressed, by adjusting the sub-array antenna spacing (i.e., the minimum sampling interval in the array) and / or the number of antenna elements in the sub-array antenna (i.e., the number of rows N and columns M) in the antenna array, so that other grating lobes are suppressed, that is Furthermore, the above requirements can also be met by adjusting the arrangement mode of the sub-array antenna.

[0067] Preferably, during the design process, ensure that the number of antenna elements in the sub-array antenna is as small as possible.

[0068] In summary, for the synthetic aperture radiometer and its antenna parameter design method provided by the present invention, by matching the null point of the sub-array antenna with the grating lobe position of the array, the grating lobe can be effectively suppressed. In a traditional SAIR system, the existence of grating lobes usually causes targets outside the non-aliasing field of view to enter the imaging result, thus misleading the detection of targets. The effective suppression of the grating lobe by the method provided by the present invention means that the signals generated by targets outside the non-aliasing field of view will not cause aliased targets in the imaging result due to the grating lobe, thereby reducing the interference of these targets to the system. By reducing aliasing interference, the system can avoid false detection and missed detection phenomena, which is of great significance for improving the detection efficiency and accuracy, especially in multi-target detection and dense target environments.

[0069] To further illustrate the antenna parameter design method of the synthetic aperture radiometer provided by the present invention, a specific embodiment is described in detail below:

[0070] The antenna array in the synthetic aperture radiometer of this embodiment is a 36-element equally spaced planar array, the minimum element spacing is 21 mm, the operating frequency is 94 GHz, corresponding to d min = 6.58λ, and its arrangement is as Figure 2 shown.

[0071] According to the formula The position of the grating lobe can be expressed as:

[0072]

[0073] Then, the number of antenna elements in the subarray antenna is set to 3×3, that is, N = M = 3. The radiation pattern of the subarray antenna is expressed as:

[0074]

[0075] In order to match the nulls of the subarray antenna with the grating lobes of the array, the following equation needs to be satisfied:

[0076]

[0077] To preferentially suppress the grating lobe closest to the main lobe of the antenna array factor, that is, k = ±1. At this time,

[0078] As described above, the nulls of the designed subarray antenna can match the grating lobes closest to the main lobe, so the first grating lobe can be effectively suppressed.

[0079] Next, two types of antennas were simulated using HFSS: a conventional antenna and a subarray antenna. As Figure 3 shown, a rectangular horn antenna was selected for the conventional antenna, and the antenna aperture was 21 mm × 16 mm; as Figure 4 shown, the aperture of the subarray antenna was the same as that of the conventional antenna, but it consisted of 3×3 horn antennas with an aperture of 7 mm × 5.33 mm. The simulation results of the radiation patterns of the conventional antenna and the subarray antenna are as Figure 5 shown, and their performance indicators such as the half-power beamwidth (HPBW), gain, and aperture size are listed in Table 1.

[0080] Table 1 Comparison of HPBW and gain of antennas

[0081]

[0082] From Figure 5 it can be seen that under the constraint of the same minimum element spacing (i.e., the spacing between subarray antennas in the antenna array), the subarray antenna generates nulls at specific angles, and its sidelobe level is significantly lower than that of the conventional antenna. As shown in Table 1, under the same size constraint, the performance indicators of the subarray antenna can reach a level comparable to that of the rectangular horn antenna, so using the subarray antenna to replace the conventional antenna will not cause a significant decline in the main performance.

[0083] Next, according to the formula multiply the array factor AF of the antenna array by the radiation patterns of the conventional antenna and the subarray antenna respectively, and the corresponding array radiation patterns can be obtained, as Figure 6 shown. From Figure 6 it can be seen that the nulls of the subarray antenna match the grating lobes closest to the main lobe, thereby effectively suppressing these grating lobes.

[0084] Furthermore, the imaging performances of synthetic aperture radiometers based on traditional arrays and sub-arrays were compared. When there is a target at or near the grating lobe and when there are multiple targets in the scene, the different original brightness temperature distributions and the imaging results of synthetic aperture radiometers based on traditional arrays and sub-arrays are as shown in Figure 7 and Figure 8 . Among them, both Figure 7 and Figure 8 include the original brightness temperature distribution, the imaging result of the synthetic aperture radiometer based on the traditional array, the imaging result of the synthetic aperture radiometer based on the sub-array, and the cross-sectional view of the imaging result.

[0085] It can be seen from Figure 7 and Figure 8 that when there are interfering targets in the scene (for example, when there is a target at or near the grating lobe), aliasing artifacts will appear in the imaging result of the synthetic aperture radiometer based on the traditional antenna array, while the synthetic aperture radiometer based on the sub-array provided by the present invention effectively suppresses the generation of artifacts and further improves the imaging quality. In the multi-point source scene, the background fluctuation and amplitude in the imaging result of the synthetic aperture radiometer based on the traditional antenna array are high, while the background in the imaging result of the synthetic aperture radiometer based on the sub-array provided by the present invention is flatter and the target is more prominent.

[0086] In summary, the synthetic aperture radiometer based on the sub-array provided by the present invention shows better performance in suppressing artifacts and reducing background noise. The present invention first analyzes the position of the grating lobe in the array factor according to the known array layout, and then designs the sub-array antenna to replace the traditional horn antenna, so that the zero point of the sub-array antenna matches the grating lobe of the array factor to suppress the grating lobe in the array pattern, and can suppress the aliasing artifacts and background interference in the imaging result without increasing the system complexity and computational complexity, while maintaining the performance of the array in terms of resolution and sensitivity.

[0087] In a second aspect, the present invention provides a synthetic aperture radiometer, in which the antenna array is used to uniformly sample the observation target in spatial frequency; each antenna in the antenna array is a sub-array antenna; the sub-array antenna includes: antenna elements arranged in N rows and M columns; both N and M are positive integers;

[0088] The antenna parameters of the synthetic aperture radiometer are designed by the antenna parameter design method provided in the first aspect of the present invention.

[0089] The related technical solutions are the same as the antenna parameter design method provided in the first aspect of the present invention, and will not be elaborated here.

[0090] In a third aspect, the present invention provides an electronic device, comprising: a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, it executes the antenna parameter design method provided in the first aspect of the present invention.

[0091] The related technical solutions are the same as the antenna parameter design method provided in the first aspect of the present invention, and will not be elaborated here.

[0092] In a fourth aspect, the present invention further provides a computer-readable storage medium, where the computer-readable storage medium includes a stored computer program, and when the computer program is run by a processor, it controls the device where the storage medium is located to execute the antenna parameter design method provided in the first aspect of the present invention.

[0093] The related technical solutions are the same as the antenna parameter design method provided in the first aspect of the present invention, and will not be elaborated here.

[0094] In a fifth aspect, the invention further provides a computer program product, including a computer program / instructions, and when the computer program / instructions are executed by a processor, they implement the antenna parameter design method provided in the first aspect of the present invention.

[0095] The related technical solutions are the same as the antenna parameter design method provided in the first aspect of the present invention, and will not be elaborated here.

[0096] It is easy for those skilled in the art to understand that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for designing antenna parameters of a synthetic aperture radiometer, characterized in that: The antenna array in the synthetic aperture radiometer is used to uniformly sample the observed target in spatial frequency; Each antenna in the antenna array is a sub-array antenna; The subarray antenna comprises: antenna elements in N rows and M columns; N and M are both positive integers; The antenna parameter design method comprises: obtaining the antenna parameters of the synthetic aperture radiometer by matching the zero point position of the subarray antenna pattern with the grating lobe position of the antenna array array factor.

2. The antenna parameter design method according to claim 1, characterized in that: The antenna parameters include: the sub-array antenna spacing, the number of rows N, the number of columns M in the antenna array, and the spacing of antenna elements in the sub-array antenna; The antenna parameter design method comprises: The sub-array antenna spacing, the number of rows N and the number of columns M in the antenna array are respectively set to corresponding preset values; The array factor of the sub-array antenna is (ξ g1 ,η g1 ) is set to 0, so that the position of the subarray antenna pattern zero point matches the position of the grating lobe closest to the main lobe of the antenna array factor, and the spacing of the antenna elements in the subarray antenna is obtained; Among them, (ξ g1 ,η g1 ) is the grating lobe position closest to the main lobe of the antenna array array factor.

3. The antenna parameter design method according to claim 2, characterized in that: The array factor expression of the subarray antenna is: Among them, (ξ,η) is an arbitrary position in the field of view coordinate system of the synthetic aperture radiometer; θ and denote the elevation angle and azimuth angle of the antenna array when observing the position (ξ,η); d sx and d sy They are respectively the antenna spacings of the antenna elements in the subarray antenna in the x-axis direction and the y-axis direction in the xy coordinate system where the antenna array is located; the x-axis direction of the xy coordinate system where the antenna array is located is parallel to the row direction of the subarray antenna, and the y-axis direction is parallel to the column direction of the subarray antenna.

4. The antenna parameter design method according to claim 3, characterized in that: ξ g1 and η g1 They are: Among them, k u1 is 1 or -1; k u1 is 1 or -1; (ξ0,η0) is the main lobe position of the antenna array array factor; Δu and Δv are the minimum sampling baselines of the subarray antenna in the x-axis direction and the y-axis direction in the xy coordinate system where the antenna array is located, respectively; d x and d y are respectively the spacings of the sub-array antennas in the x-axis direction and the y-axis direction in the xy coordinate system where the antenna array is located; λ is the wavelength corresponding to the operating frequency of the comprehensive aperture interferometer.

5. The antenna parameter design method according to claim 4, characterized in that: In the xy coordinate system where the antenna array is located, the antenna spacing of the antenna elements in the subarray antenna in the x-axis direction Antenna spacing in the y-axis direction 6. The antenna parameter design method according to any one of claims 2 to 5, characterized in that: Also includes: After obtaining the spacing of antenna elements in the subarray antenna, the subarray antenna spacing, the number of rows N and / or the number of columns M in the antenna array are adjusted with the array factor of the subarray antenna being equal to 0 at any grating lobe position of the antenna array array factor.

7. A synthetic aperture radiometer, characterized in that: The antenna array inside is used to uniformly sample the observed target in spatial frequency; Each antenna in the antenna array is a sub-array antenna; the sub-array antenna includes: antenna elements in N rows and M columns; N and M are both positive integers; The antenna parameters of the synthetic aperture radiometer are designed by the antenna parameter design method described in any one of claims 1-6.

8. An electronic device, characterized in that: include: A memory and a processor, wherein the memory stores a computer program, and the processor executes the antenna parameter design method according to any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed by a processor, the device where the storage medium is located is controlled to execute the antenna parameter design method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The invention comprises a computer program / instruction, which, when executed by a processor, implements the antenna parameter design method according to any one of claims 1 to 6.

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