Direction of Arrival Estimation Method Based on Nested Electromagnetic Vector Sensor Array

Abstract

The invention discloses a direction of arrival estimation method based on a nested electromagnetic vector sensor array, and mainly solves the problems that mutual coupling between each electromagneticcomponent of the electromagnetic vector sensor array is more serious and hardware implementation of the electromagnetic vector sensor array is complicated. The implementation process comprises the steps of constructing a nested electromagnetic vector sensor array; obtaining fuzzy estimates of a target direction cosine using ESPRIT algorithm; pairing fuzzy estimation values of the target directioncosine; obtaining no fuzzy estimation values of the target direction cosine using a vector cross product algorithm of a single separated electromagnetic vector sensor; conducting fuzzy resolution onthe fuzzy estimation values of the target direction cosine, conducting trigonometric operations, and obtaining two-dimensional direction of arrival estimation values of a spatial target. According tothe direction of arrival estimation method based on the nested electromagnetic vector sensor array, the complexity of the mutual coupling and hardware implementation between various electromagnetic components is reduced, the aperture of the whole array is expanded, the accuracy of angle measurement is improved, and the method can be used for angle positioning of a target by a radar.

Description

technical field [0001] The invention belongs to the technical field of signal processing, and in particular relates to a method for estimating a direction of arrival, which can be used for angular positioning of a target by a radar. Background technique [0002] Electromagnetic vector sensor array radar is a new system radar with great potential to adapt to modern warfare. Compared with the conventional array, the electromagnetic vector sensor array can perceive the electromagnetic components of the incident wave in different directions, thereby extracting more information such as polarization, etc., and the combination of polarization domain information and spatial domain information can further improve the multidimensional parameters of the signal Estimation and signal detection performance. Therefore, in recent decades, target spatial angle estimation based on electromagnetic vector sensor arrays has received widespread attention. The electromagnetic vector sensor compo...

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Problems solved by technology

However, since the components of the separate electromagnetic vector sensor are separated in space, the phase shift factor is introduced, so the vector cross product algorithm cannot be directly used for target DOA estimation

[0003] In 2011, Professor K.T.Wong proposed a separate electromagnetic vector sensor based on parallel line structure, and successfully realized the application of the vector cross product DOA estimation algorithm in the separate electromagnetic vector sensor, but this method has relatively strict requirements on the position of the array element , and this method only discusses the vector cross product algorithm in the case of a single separate electromagnetic vector sensor, and does not discuss its application in the array

However, previous studies focused on the case where the array unit is a single polarized antenna, and the collected electromagnetic information is incomplete, and the case of using a separate electromagnetic vector sensor as an antenna unit of a nested array has not been discussed

[0005] In 2014, Keyong Han proposed an array that combines the common-point electromagnetic vector sensor with the uniform linear array ULA, and used the tensor method to realize the estimation of the target DOA. However, since the array unit of the array is a common-point electromagnetic Vector sensor, the mutual coupling between the components of the electromagnetic vector sensor is relatively large, and affected by the array aperture of the uniform linear array itself and the array element spacing not greater than λ / 2, the mutual coupling between each electromagnetic vector sensor seriously affects the target The estimation performance of DOA. In addition, this method uses tensors to estimate the DOA of the target, and the calculation amount is relatively large.

[0006] To sum up, both a single separate electromagnetic vector sensor and a nested array can correctly estimate the direction of arrival of the target, but they all have certain limitations. The influence of the mutual coupling between the components of the sensor and the mutual coupling between the electromagnetic vector sensors causes the estimation accuracy of the direction of arrival of the target to decrease

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