A unilateral two-point squint imaging method for buildings based on mimo through-wall radar

Abstract

The invention discloses an MIMO through-wall radar based single-side double-point squint imaging method of a building. An MIMO through-wall radar carries out real-aperture squint detection at two detection points selected in the single side of the building, and collected real aperture echoes of the two points from two squint images which include part corners of the building and static objects in the building via a backward projection imaging algorithm. Overlapped fusion and 2D constant false alarm detection are carried out on the two squint images, the integrity of all corner images of the building is ensured, the layout of all walls can be determined, corner image sidelobe and multipath phantom interference are inhibited, distribution of static objects therein can be determined, and a panorama image of the building including clear corner images and static object images is obtained finally. The corner image and the static object image can be used to determine the wall layer out and the static object distribution respectively, and imaging detection for the wall layout and the internal static objects of the building is realized.

Description

technical field [0001] The invention relates to a radar imaging method, in particular to a unilateral two-point squint imaging method for buildings based on MIMO through-wall radar. Background technique [0002] In the application of building imaging detection based on through-the-wall radar, the wall layout of the building and the internal stationary targets (furniture, home appliances, stationary human body, etc.) are the other two basic detection objects besides the moving human body. The attenuation of wall penetration causes the echo intensity of the wall to be much higher than that of the internal static target, so different processing methods are required to obtain the wall layout image and the static target image. [0003] For wall layout imaging, the influence of weak internal stationary target echoes can be ignored. Due to the characteristics of wall specular reflection, the existing methods to obtain all wall echoes of buildings require at least through-wall radar...

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Problems solved by technology

[0003] For wall layout imaging, the influence of weak internal stationary target echoes can be ignored. Due to the characteristics of wall specular reflection, the existing methods to obtain all wall echoes of buildings require at least through-wall radar on both sides of adjacent buildings. , from two perspectives perpendicular to the surface of the walls on both sides, the "front-facing" synthetic aperture multi-point detection is carried out respectively, that is, the bilateral multi-point front-facing detection of the building, the echo data collection and processing are very complicated, and the surrounding of the building is required to meet the bilateral multi-point Facing the detection conditions squarely, the achievability is not high

[0004] For internal static target imaging, it is only necessary to perform single-view synthetic aperture detection or multiple input multiple output (MIMO) real aperture detection on one side of the building to obtain sufficient target echoes, but the wall echo performance For strong clutter interference, the side lobes of the wall image will cover up the static target image. The performance of existing wall echo suppression methods such as adaptive filtering algorithm and CLEAN algorithm is severely degraded when facing non-uniform walls.

In addition, there are complex multipath clutter in the closed space of buildings, which will cause phantom interference to the imaging of stationary targets. The existing multipath phantom suppression methods are mainly divided into two categories. One is to use the specular reflection characteristics of the wall and the position of the wall to solve However, this method relies on the ideal wall specular reflection characteristics and wall position information that is usually unknown or has estimation errors, the processing effect is limited, and some target images may be lost when there are multiple targets ; Another type of method with better processing effect needs to detect buildings with bilateral front view (two viewing angles). The complex data collection and processing brought by the detection (synthetic aperture), the harsh detection environment and other problems reduce the practicability of the method

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