技术领域technical field
本发明涉及的是一种水声信号处理方法。The invention relates to an underwater acoustic signal processing method.
背景技术Background technique
超短基线阵因其自身尺寸小，易于安装等特点，在水下目标定位中被广泛应用。传统超短基线阵常采用尺寸小于发射信号半波长的三角阵，由于阵列孔径小，传统的超短基线阵远距离定位精度往往不高，可以通过改进阵型或增大阵列孔径来解决这一问题，但这些手段会带来相位模糊的问题。所以，在提高超短基线阵的定位精度的同时，兼顾抗相位模糊的方法对于超短基线定位系统十分重要。Due to its small size and easy installation, the ultra-short baseline array is widely used in underwater target positioning. The traditional ultra-short baseline array often uses a triangular array whose size is smaller than half the wavelength of the transmitted signal. Due to the small aperture of the array, the long-distance positioning accuracy of the traditional ultra-short baseline array is often not high. This problem can be solved by improving the array or increasing the array aperture. , but these methods will bring the problem of phase ambiguity. Therefore, while improving the positioning accuracy of the ultra-short baseline array, the method of anti-phase ambiguity is very important for the ultra-short baseline positioning system.
国内外学者采用过多种方法解决这一问题，具有代表性的研究主要有：喻敏([1]喻敏,惠俊英,孙大军.超短基线基阵基元相移差的测量[J].应用声学,2006(04):229-233.)提出了利用8元阵的方法，由同一方向上间距最大的阵元组合提高系统的定位精度，再通过小于半波长的阵元组合进行相位补偿，实现了抗相位模糊；郑翠娥([2]郑翠娥,李琪,孙大军,张殿伦.一种超短基线定位系统阵型的改进方法[J].中国海洋大学学报(自然科学版),2009,39(03):505-508.)改变了发射信号的形式，利用了双脉冲的发射信号，使用正交4元阵定位法解决相位模糊问题，在去掉了冗余阵元的同时提高了定位精度；郑恩明([3]郑恩明,陈新华,孙长瑜,余华兵.一种四元超短基线阵实现高精度定位[J].应用声学,2013,32(01):15-22.)通过优化阵型形成间距不等的四元阵，在减小阵元个数的同时，简化了发射信号的形式，并且保证了与文献[1]中的8元阵型相当的定位精度；但是，受限于物理工艺，对于频率较高的信号，阵元间距通常难以满足小于半波长的条件，此时上述方法不再适用。Scholars at home and abroad have used many methods to solve this problem, and the representative research mainly includes: Yu Min ([1] Yu Min, Hui Junying, Sun Dajun. Measurement of phase shift difference of ultra-short baseline array elements[J ]. Applied Acoustics, 2006 (04): 229-233.) proposed the method of using an 8-element array to improve the positioning accuracy of the system by combining the array elements with the largest spacing in the same direction, and then through the combination of array elements less than half the wavelength. Phase compensation to achieve anti-phase ambiguity; Zheng Cui'e ([2] Zheng Cui'e, Li Qi, Sun Dajun, Zhang Dianlun. An improved method for ultra-short baseline positioning system formation[J]. Journal of Ocean University of China (Natural Science Edition), 2009 ,39(03):505-508.) changed the form of the transmitted signal, used the double-pulse transmitted signal, and used the orthogonal 4-element array positioning method to solve the phase ambiguity problem, and improved the Positioning accuracy; Zheng Enming ([3] Zheng Enming, Chen Xinhua, Sun Changyu, Yu Huabing. A quaternary ultra-short baseline array to achieve high-precision positioning [J]. Applied Acoustics, 2013, 32(01): 15-22.) through optimization The formation forms a quaternary array with unequal spacing, which simplifies the form of the transmitted signal while reducing the number of array elements, and ensures the positioning accuracy equivalent to the 8-element formation in the literature [1]; however, it is limited by Physical technology, for signals with higher frequencies, it is usually difficult to satisfy the condition that the array element spacing is less than half a wavelength, and the above method is no longer applicable at this time.
发明内容Contents of the invention
本发明的目的在于提供一种能够解决当信号频率较高难以满足阵列孔径小于半波长的条件时所产生的相位模糊问题的超短基线阵抗相位模糊的方法。The purpose of the present invention is to provide an ultra-short baseline array anti-phase ambiguity method that can solve the phase ambiguity problem that occurs when the signal frequency is high and it is difficult to meet the condition that the array aperture is smaller than half the wavelength.
本发明的目的是这样实现的：The purpose of the present invention is achieved like this:
(1)根据超短基线阵的阵型，获得同一方向上任意两个阵元间相位的最大模糊周期数，确定两个阵元间相位模糊周期数的取值范围；(1) According to the formation of the ultra-short baseline array, the maximum ambiguity period number of the phase between any two array elements in the same direction is obtained, and the value range of the phase ambiguity period number between the two array elements is determined;
(2)根据两个阵元测得的相位差和最大模糊周期数计算出该组阵元所有可能的目标方向角；(2) Calculate all possible target orientation angles of the group of array elements according to the phase difference measured by the two array elements and the maximum number of ambiguity cycles;
(3)计算目标方向角的扇面宽度系数，设置目标方向角的扇面宽度；(3) Calculate the sector width coefficient of the target direction angle, and set the sector width of the target direction angle;
(4)根据所有可能的目标方向角和扇面宽度，在直方图上统计所有目标方向角度的出现次数，出现次数最多的角度即为估计的目标方向角；(4) According to all possible target direction angles and sector widths, the number of occurrences of all target direction angles is counted on the histogram, and the angle with the largest number of occurrences is the estimated target direction angle;
(5)根据估计的目标方向角计算出各组阵元的模糊周期数的估计值。(5) Calculate the estimated value of the fuzzy cycle number of each array element according to the estimated target direction angle.
本发明提出了一种超短基线阵抗相位模糊的方法，以解决当信号频率较高难以满足阵列孔径小于半波长的条件时所产生的相位模糊问题。The invention proposes an ultra-short baseline array anti-phase ambiguity method to solve the phase ambiguity problem generated when the signal frequency is high and it is difficult to meet the condition that the array aperture is smaller than half the wavelength.
本发明的有益效果是：(1)在基阵接收到的信号频率较高，难以满足阵列孔径小于半波长的条件下，能够有效实现抗相位模糊，突破了阵列尺寸对于基阵定位性能的限制；(2)与传统的三角阵相比可以提高定位精度，并且充分利用了冗余的阵元信息，在关注的角度范围内即θ∈[-60°，60°]时，抗相位模糊的正确性近似100％。The beneficial effects of the present invention are: (1) Under the condition that the signal frequency received by the array is relatively high and it is difficult to meet the condition that the array aperture is less than half a wavelength, the anti-phase ambiguity can be effectively realized, breaking through the limitation of the array size on the positioning performance of the array ; (2) Compared with the traditional triangular array, the positioning accuracy can be improved, and the redundant array element information is fully utilized. In the angle range of concern, that is, θ∈[-60°, 60°], the anti-phase ambiguity The accuracy is approximately 100%.
附图说明Description of drawings
图1为本方法对应的基阵阵型示意图；Fig. 1 is the schematic diagram of the matrix formation corresponding to this method;
图2为目标方向角为-50度时各角度出现次数的统计直方图；Figure 2 is a statistical histogram of the number of occurrences of each angle when the target direction angle is -50 degrees;
图3为不同目标方向角度的抗相位模糊正确率。Figure 3 shows the correct rate of anti-phase ambiguity for different target direction angles.
具体实施方式Detailed ways
下面举例对本发明做更详细的描述。The following examples describe the present invention in more detail.
首先对本方法中使用到的基本参数作如下说明：本方法中举例采用的超短基线阵的阵型为8元十字阵，阵型示意图如图1所示。阵元间距的具体数值为d14＝0.21m，d12＝0.019m，d23＝0.026m。目标信号形式为单频CW信号，信号频率f＝75kHz，声音在海洋传播速度为c＝1500m/s，相位差测量误差最大为6°。确定好基本参数后按照如下步骤进行：First, the basic parameters used in this method are explained as follows: the formation of the ultra-short baseline array used in this method is an 8-element cross array, and the schematic diagram of the formation is shown in Figure 1. The specific values of the array element spacing are d14 =0.21m, d12 =0.019m, and d23 =0.026m. The target signal is in the form of a single-frequency CW signal, the signal frequency is f=75kHz, the propagation speed of sound in the ocean is c=1500m/s, and the phase difference measurement error is up to 6°. After determining the basic parameters, proceed as follows:
(1)根据超短基线阵的阵型，计算出同一方向上任意两个阵元间相位的最大模糊周期数，确定两个阵元间相位模糊周期数的取值范围。(1) According to the formation of the ultra-short baseline array, calculate the maximum ambiguity period of the phase between any two array elements in the same direction, and determine the value range of the phase ambiguity period between the two array elements.
设阵元i与阵元j的间距为dij，那么阵元i与阵元j相位的最大模糊周期N为：Suppose the distance between array element i and array element j is dij , then the maximum fuzzy period N of the phase between array element i and array element j is:
最大模糊周期数是两阵元间所有可能的模糊周期数中的最大值，因此在计算方向角时所有的模糊周期数都不能够超过最大模糊周期数。The maximum number of fuzzy cycles is the maximum value of all possible fuzzy cycles between two array elements, so all fuzzy cycles cannot exceed the maximum number of fuzzy cycles when calculating the direction angle.
设阵元i和阵元j的间距为dij，两阵元间所有可能的模糊周期数为nij，那么nij的取值范围是：Suppose the distance between array element i and array element j is dij , and the number of all possible fuzzy cycles between two array elements is nij , then the value range of nij is:
nij∈[-N,N] (2)nij ∈[-N,N] (2)
根据已知阵型和参数，在同一方向上有4个阵元所以有6种阵元组合，对应的存在6个最大模糊周期数。间距dij与最大周期数N以及取值范围的关系如下表所示：According to the known formation and parameters, there are 4 array elements in the same direction, so there are 6 array element combinations, and there are 6 maximum fuzzy cycles correspondingly. The relationship between the distance dij and the maximum number of cycles N and the value range is shown in the following table:
(2)根据两个阵元测得的相位差和最大模糊周期数计算出该组阵元所有可能的目标方向角。(2) Calculate all possible target orientation angles of the group of array elements according to the phase difference measured by the two array elements and the maximum number of ambiguity cycles.
目标方向角的计算公式为：The formula for calculating the target orientation angle is:
其中，表示阵元i与阵元j之间的测得的相位差，nij表示阵元i与阵元j之间所有可能的模糊周期数，dij为阵元i与阵元j的间距，λ为波长，θij为阵元i与阵元j之间解出的所有可能的目标方向角。in, Indicates the measured phase difference between array element i and array element j, nij indicates the number of all possible ambiguity cycles between array element i and array element j, dij is the distance between array element i and array element j, λ is the wavelength, and θij is all possible target direction angles solved between array element i and array element j.
根据测得相位差和已知的阵元间距，将模糊周期数的所有可能取值依次代入式(3)进行计算就能得出所有可能的目标方向角。例如阵元12之间测得的相位差为又因为阵元间的最大模糊周期数为1，所以nij可取为-1，0，1，将和nij带入公式(3)，即可求得阵元1和阵元2之间所有可能的方向角。对所有的阵元组合重复这一计算过程，就能得到所有可能的目标方向角。According to the measured phase difference and the known array element spacing, all possible values of the ambiguity period number are substituted into formula (3) for calculation to obtain all possible target orientation angles. For example, the phase difference measured between array elements 12 is And because the maximum fuzzy cycle number between array elements is 1, so nij can be taken as -1, 0, 1, and the and nij are brought into formula (3), and all possible orientation angles between array element 1 and array element 2 can be obtained. By repeating this calculation process for all array element combinations, all possible target orientation angles can be obtained.
(3)计算目标方向角的扇面宽度系数，设置目标方向角的扇面宽度。(3) Calculate the sector width coefficient of the target direction angle, and set the sector width of the target direction angle.
目标方向角扇面宽度的大小由扇面宽度系数和相位差测量容限共同决定。扇面宽度系数为目标方向角计算公式对相位差的偏导数值的2倍，相位差测量容限主要与测量误差的最大值有关。目标方向角扇面宽度等于扇面宽度系数与相位差测量容限的乘积。例如对于阵元1和阵元2，相位差测量容限为6°。设阵元间测得相位差为-50°，那么计算出的偏导数为0.1712，扇面宽度系数就为0.3424，计算得到目标方向角扇面宽度为2.0544°。The size of the fan width of the target direction angle is jointly determined by the fan width coefficient and the phase difference measurement tolerance. The sector width coefficient is twice the partial derivative value of the target direction angle calculation formula for the phase difference, and the phase difference measurement tolerance is mainly related to the maximum value of the measurement error. The sector width of the target direction angle is equal to the product of the sector width coefficient and the phase difference measurement tolerance. For example, for array element 1 and array element 2, the phase difference measurement tolerance is 6°. Assuming that the measured phase difference between the array elements is -50°, then the calculated partial derivative is 0.1712, the sector width coefficient is 0.3424, and the target direction angle sector width is calculated to be 2.0544°.
(4)根据所有可能的目标方向角和扇面宽度，在直方图上统计所有目标方向角度的出现次数，出现次数最多的角度即为估计的目标方向角。(4) According to all possible target direction angles and sector widths, count the occurrence times of all target direction angles on the histogram, and the angle with the most occurrence times is the estimated target direction angle.
根据计算出的所有可能的目标方向角和扇面宽度，对不同角度的出现次数进行统计。统计方法为任意角度每出现1次就在记录的出现次数中加1，在直方图上记录所有角度出现总次数的统计结果，出现次数最多的角度就是目标方向角的估计值。According to all possible target orientation angles and sector widths calculated, count the occurrence times of different angles. The statistical method is to add 1 to the recorded number of occurrences every time any angle appears, and record the statistical results of the total number of occurrences of all angles on the histogram. The angle with the most occurrences is the estimated value of the target direction angle.
选取-50°作为已知目标方向角进行论证，目标方向角的估计结果如图2所示。图2表示使用直方图统计各个角度出现的次数，可以看到出现次数最多的角度是-50°，故-50°是目标方向角的估计值。Select -50° as the known target direction angle for demonstration, and the estimated result of the target direction angle is shown in Figure 2. Figure 2 shows the use of the histogram to count the number of occurrences of each angle. It can be seen that the angle with the most occurrences is -50°, so -50° is the estimated value of the target direction angle.
(5)根据估计的目标方向角计算出各组阵元的模糊周期数的估计值。(5) Calculate the estimated value of the fuzzy cycle number of each array element according to the estimated target direction angle.
设估计的目标方向角为将估计的目标方向角作为已知量代入求周期模糊数的公式(4)，求得估计的模糊周期数。求模糊周期数的公式为：Let the estimated target orientation angle be will estimate the target orientation angle As a known quantity, it is substituted into the formula (4) for calculating the period fuzzy number, and the estimated fuzzy period number is obtained. The formula for finding the number of fuzzy cycles is:
其中，表示阵元i与阵元j之间的测得的相位差，表示阵元i与阵元j之间所有可能的模糊周期数的估计值，dij为阵元i与阵元j的间距，λ为波长，为阵元i与阵元j之间解出的目标方位角的估计值。通过公式(4)求出的即为所求的模糊周期数估计值。in, Indicates the measured phase difference between array element i and array element j, Indicates the estimated value of all possible ambiguity periods between array element i and array element j, dij is the distance between array element i and array element j, λ is the wavelength, is the estimated value of the target azimuth angle solved between array element i and array element j. Calculated by formula (4) That is, the estimated value of the fuzzy cycle number sought.
为验证上述方法的有效性，下面对不同目标方向角的抗相位模糊性能进行分析，结果如图3所示。可见，整个角度域最低正确率高于98.8％，当方向角θ∈[-60°，60°]时，检测概率达到100％，。因此，本方法能准确完成抗相位模糊的任务。In order to verify the effectiveness of the above method, the anti-phase ambiguity performance of different target orientation angles is analyzed below, and the results are shown in Figure 3. It can be seen that the minimum accuracy rate in the entire angle domain is higher than 98.8%, and when the direction angle θ∈[-60°, 60°], the detection probability reaches 100%. Therefore, this method can accurately complete the task of anti-phase ambiguity.
最后应说明的是，以上实施例仅用以描述本发明的技术方案而不是对本技术方法进行限制，本发明在应用上可以延伸为其他的修改、变化、应用和实施例，并且因此认为所有这样的修改、变化、应用、实施例都在本发明的精神和教导范围内。Finally, it should be noted that the above embodiments are only used to describe the technical solutions of the present invention rather than limit the technical methods of the present invention. The present invention can be extended to other modifications, changes, applications and embodiments in application, and therefore it is considered that all such Modifications, changes, applications, and embodiments are all within the spirit and teaching scope of the present invention.
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| CN201810261916.0ACN108845290B (en) | 2018-03-28 | 2018-03-28 | Method for resisting phase ambiguity of ultra-short baseline array |
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| CN201810261916.0ACN108845290B (en) | 2018-03-28 | 2018-03-28 | Method for resisting phase ambiguity of ultra-short baseline array |
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