Ground penetrating radar (GPR) is one of the most recommended tools for routine inspection tunnel linings. However, rebars in reinforced concrete produce a strong shielding effect on electromagnetic waves, which may hinder interpretation GPR data. In this work, we proposed method to improve identification lining voids by designing generative adversarial network-based rebar clutter elimination network (RCE-GAN). The designed has two sets generators and discriminators, introducing...

Ground penetrating radar (GPR) is considered an effective tool to detect tunnel lining voids. In this paper, experimental study was carried out using a physical model evaluate the performances of different antenna frequencies. We built 4.2 m–long, m–wide, and 2.0 m–high simulate secondary lining, initial surrounding rock structure. model, we created four categories voids, which are voids in linings, delamination between sand, void buried real cases engineering. The GPR wave velocities sand...

Spotlight mode offers finer azimuth resolution than that achievable in stripmap using the same physical antenna. The most popular spotlight synthetic aperture radar (SAR) reconstruction method is classic polar format algorithm (PFA). However, PFA needs to perform range and interpolation operations during SAR imaging, which, turn, affect imaging precision computation efficiency. In this letter, we present a novel algorithm, which may avoid by double chirp-Z transform. also analyze nondefocus...

In highly squinted synthetic aperture radar (SAR) motion compensation, the map-drift (MD) algorithm cannot estimate Doppler chirp rate accurately when range walk is compensated in azimuthal time domain. This problem stems from influence of position-dependent (i.e., space-variant) phases, which are introduced by compensation domain on estimation. letter proposes a space-variant phase-error matching MD that can improve precision estimating for SAR removing phases.

In the numerical simulation of a real-time hybrid testing, integration algorithms are one most-effective methods to obtain solutions discrete equations motion at selected time steps. A variety have been well established using different methods. order apply traditional assumptions introduced in corresponding make expressions for both displacement and velocity explicit form. this paper, pole-mapping rule from domain is used develop new algorithm. Based on control theory, properties all...

We present a simple and efficient method to seamlessly stitch the images according stitching line based on an energy map. The power of this lies in integration many superior features at same time, it is still efficient. One striking feature our approach that philosophy human eyes mostly notice only salient image skirts round important objects like faces avoid distorting content seam area. Robustness another characteristic de-ghosting when moving are left which will appear blurry "ghosted."...

Ghosting artifact in the field of image stitching is a common problem and elimination it not an easy task. In this paper, we propose intuitive technique according to line based on novel energy map which essentially combination gradient indicates presence structures prominence determines attractiveness region. We consider region significance only if both structural attractive. Using improved map, can easily skirt around moving objects or salient parts philosophy that human eyes mostly notice...

The high-resolution imaging of a highly squinted synthetic aperture radar remains difficult because the severe coupling between range and azimuth. "Squint minimization" compensates for walking in azimuth time domain, which efficiently increases orthogonality However, this "squint introduces space-variant phases, can be compensated by nonlinear chirp-scaling (ANCS) algorithm using large computational loads. In letter, an overlapped subaperture (AOSA) is proposed to compensate these phases...

Synthetic aperture ladar (SAL), whose carrier is laser, makes use of synthetic processing to improve the resolution images. Since wavelength laser very short, it would be sensitive for SAL vibration platform. This paper presents how from platform has effects on imaging quality SAL. We take simple harmonic oscillation example and present an analytic formula instantaneous range based 3-D error model. Then, we conclude that effect in cross-track cannot ignored related peak acceleration...

The crosshole ground penetrating radar (GPR) is a widely used tool to map subsurface properties, and inversion methods are derive electrical parameters from GPR data. In this paper, probabilistic algorithm that uses Markov chain Monte Carlo (MCMC) simulations within the Bayesian framework implemented infer posterior distribution of relative permittivity medium. Close attention paid critical elements method, including forward model, data type prior information, their influence on results...

Bayesian inversion of crosshole ground penetrating radar (GPR) data is capable characterizing the subsurface dielectric properties and qualifying associated uncertainties. Markov chain Monte Carlo (MCMC) simulations within usually require thousands to millions forward model evaluations for parameters hit their posterior distributions. Therefore, CPU cost a key issue that influences efficiency method. In this paper we implement widely used straight-ray our framework. Based on synthetic unit...

The main purpose of this paper is to examine the effects incomplete boundary conditions and actuator delay on dynamic responses seismically excited civil structures. A set constraint equations representing reserved interface degrees-of-freedom (DOFs) are introduced form a mechanical model real-time hybrid simulation (RTHS) (referred as RTHS-I&A) for multi-degree-of-freedom (MDOF) system based substructure method (DSM). Then, RTHS-I&A modeled by discrete closed-loop transfer function...

In this paper we discuss the implementation of crosshole ground-penetrating radar (GPR) method in diaphragm wall defect detection. The construction process a panel is introduced and different types defects including crack, void, sludge accumulation, joint leakage, split are summarized. zero-offset profiling (ZOP) survey advised to be carried out quickly locate anomalous zones walls, followed by multi-offset gather (MOG) characterize exact position, size shape defects. Numerical simulations...

The spatial resolution of a conventional imaging lidar system is constrained by the diffraction limit telescope's aperture. combination and synthetic aperture (SA) processing techniques may overcome pave way for higher air borne or space remote sensor. Regarding transmitting frequency modulation continuous-wave (FMCW) signal, motion during transmission sweep reception corresponding echo were expected to be one major problems. given modified Omega-K algorithm takes continuous into account,...

Direct integration algorithms are effective methods to solve the temporally discretized differential equations of motion for structural dynamics. Numerous researchers have worked out various achieve desirable properties explicit expression, unconditional stability, and controllable numerical dissipation. However, studies involving dispersion limited. In this paper, a precorrected bilinear transformation from continuous domain discrete associating with pole-matching based on control theory is...

In this study, the finite‐time control problem is studied for discrete time‐varying systems with randomly occurring non‐linearity and missing measurements. The modelled according to a Bernoulli distributed white sequence known conditional probability. measurements phenomenon assumed occur in random way probabilities are upper lower bounds. Two sufficient conditions established existence of state feedback output controllers, which guarantee stochastic stability closed‐loop systems. recursive...

The image scene is limited by the small size of spot, which linked with short wavelength laser in synthetic aperture ladar (SAL). common wide-scene imaging mode radar, i.e., terrain observation progressive scans mode, extended and applied SAL. A suitable algorithm also proposed according to characteristics signal. First, azimuth prefiltering based on spectrum analysis adopted eliminate aliasing caused steering antenna beam. Then, improved frequency scaling complete range compression cell...

Image Stitching, also be called photo stitching, is the process of combining multiple photographic images with overlapping fields view to produce a segmented panorama or high-resolution image. stitching challenging in two fields. First, sequenced photos taken from various angles will have different brightness. This certainly lead un-nature stitched result no harmony Second, ghosting artifact due moving objects common problem and elimination it not an easy task. paper presents several novel...