Target speed estimation method based on sub-aperture radar interference

Abstract

The invention discloses a target speed estimation method based on sub-aperture radar interference, and the method comprises the steps: dividing an original aperture of a synthetic aperture radar into a plurality of sub-apertures with equal length, outputting the sub-apertures to obtain signals of a plurality of sub-apertures, and carrying out the interference processing of the signals of the sub-apertures to generate a phase difference; and estimating the Doppler coefficient and the speed of the target object according to the phase difference. The method can be applied to long-distance, all-time, all-weather, macroscopic, large-scale and real-time detection of moving targets such as vehicles and ships, and overcomes the defects that the synthetic aperture radar image becomes fuzzy and generates position offset due to Doppler frequency shift generated by the moving targets.

Description

technical field [0001] The invention belongs to the technical field of radar monitoring, in particular to a target speed estimation method based on sub-aperture radar interference. Background technique [0002] With the acceleration of urban construction, surface deformation poses a potential risk to the hazards of human living environment. Surface deformation is mainly divided into instantaneous sudden deformation and continuous slow deformation. [0003] The main cause is land subsidence caused by large-scale urban engineering construction and excessive groundwater extraction. Land subsidence has the characteristics of slow development of causes, long duration and difficult prevention and control, which will cause great harm to high-speed railways, buildings and infrastructure, and lifeline projects. Therefore, long-term continuous monitoring of slow deformation such as land subsidence is very important. [0004] At present, the commonly used surface deformation monitor...

AI Technical Summary

Problems solved by technology

However, the radar measures the slant distance, so it is impossible to tell whether the displacement is from the horizontal direction or the vertical direction, that is, there is direction ambiguity

The satellite interferometric radar measurement only obtains the surface deformation component along the radar line of sight (LoS), and cannot obtain the three-dimensional deformation of the real surface (vertical, east-west, and north-south deformations), that is, the satellite interferometric radar surface deformation direction is blurred, These shortcomings limit the use of satellite interferometric radar in the field of real surface three-dimensional deformation monitoring such as land subsidence, landslides, volcanic activities, and earthquakes.

[0005] However, satellite interferometric radar deformation observation has the disadvantage of inherent direction ambiguity in slant distance measurement, and it is easy to be disturbed by systematic errors caused by surface deformation, resulting in the problem of space-time loss of coherence. Therefore, we propose a sub-aperture radar interferometric method based on The target speed estimation method of

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