High-resolution Target Shape Fast Imagingalgorithm For Ultra-wideband Through-wall Bistatic Radar

UWB through-wall radar possesses the advantages of high resolution,anti-interference ability and other characteristics in through wall imaging, which hasgreat potential in fields of detecting, rescue, counter-terrorism, security, war and soon. UWB through wall radar imaging algorithm has become the hot research topic inrecent years at home and abroad. In order to overcome the shortcomings thatincludes unsuitable for real-time imaging and image fuzzy of traditional imagingalgorithms, people focus on the imaging algorithms of target boundary in recentyears. SEABED algorithm and Envelope algorithm are the two kinds of classicalalgorithms of target shape imaging, but these algorithms all have their own defects,such as poor anti-noise capability and poor accuracy.. For the traditional imagingalgorithm, it depends on the method of pixel energy superposition to finish imaging,but these algorithms usually lead to the complicated process and large amount ofcalculation, which is suitable for fast imaging of targets and real-time applications.Although the current algorithms of object boundary are able to restore the targetboundary quickly, it still exist some shortcomings. The SEABED imaging algorithmhas low ability of anti-noise, and the circular envelope imaging algorithm needs toimprove its accuracy of imaging. Therefore, how to overcome the influence of noisein the environment of the imaging process and how to increase the precision of targetimaging algorithm in detail are the emphasis of the study. In this paper, combinedwith the current mainstream UWB through wall radar imaging algorithm in targetboundary, the high resolution fast target imaging algorithm has been discussed. Inorder to improve the accuracy of algorithms and the anti-noise performance, somemore effective and perfect algorithms have been put forward. The main work of thispaper as the following:Base on the bistatic UWB-TW radar, this paper presents a target shape imagingalgorithm with the envelope of ellipses. The ellipse model regarding a targetboundary is established by analyzing the geometry relationship between the targetboundary and the coordinates of antennas. With the wall compensation method, theimproved performance of the proposed algorithm is verified by numericalsimulations and an experiment.According to3-D imaging, this paper presents a principle of Envelope ofEllipses for3-D imaging algorithm of UWB through wall radar. The algorithm combines the locations of bistatic antenna and the target to create geometrica lrelationship and the ellipsoid model tangent structure with its boundary. Accordingto this relationship, it treat ellipsoidal surfaces as the actual target boundary.Theoretical analysis and simulation results show that, the algorithm can work well inthe noise environment on the object boundary in3-D through wall imaging, which ismore conducive to the application in the real scene.Aiming at solving these problems, this paper proposes a principle of Envelopeof Ellipses Based on UWB through wall radar moving target imaging algorithm. Thealgorithm combines the tectonic geometry between bistatic antenna and the targetboundary to construct some elliptic envelopes, and then according to the equivalentfor the point of tangency boundary and the center of the imaging point, completesreduction and reconstruction process on the object boundary. The experimentalresults show that the algorithm not only reconstructs the target boundary of randomcurve movement behind the wall but also has higher robustness, precision and highreal time for the needs of practical applications.