Abstract Scannerless time-of-flight three-dimensional imaging, the successor to raster scanning relies on large-scale detector arrays obtain high pixel resolution; however, manufacturing limitations lead a bottleneck in imaging resolution. Here, we report methodology for laser using code division multiple access, which involves three key steps. Optical encoding is carried out pulsed generate space-time encoded beams projection. multiplexing subdivides backscattered light signals and...

A modified Levenberg-Marquardt (LM) method is proposed to improve the waveform-decomposition efficiency of light detection and ranging (LiDAR). The conventional constant-model-based LM fitting algorithm subsequently using two models: linear model exponential model. By revising update coefficient damping term make it consistent with variation residual error, magnitude oscillation effectively reduced provide better convergence. models were experimentally verified observed data acquired by our...

Obtaining accurate 3D perception from video sequences is a core topic in computer vision and robotics, as it forms the basis for subsequent scene analysis. ToF (Time of Flight) cameras have advantages low cost fast imaging to assist reconstruction work. Aiming at defects camera such resolution small field view, this paper proposes splicing algorithm camera, which introduces point cloud curvature density features compared with traditional Iterative Closest Point (ICP) optimizes matching based...

The lidar full-waveform echo can be decomposed into a series of components each which essentially considered as Gaussian function models. In this paper, we use empirical mode decomposition to decompose the original intrinsic functions (IMFs) and final residual. noise-level is estimated based on first IMF. IMF energy density then compared white-noise theoretical spread lines 99% confidence-limit level determine whether some IMFs are contain information. A suitable selected comparison result....

The light detection and ranging (LIDAR) full-waveform echo decomposition method based on empirical mode (EMD) the local-Levenberg-Marquard (LM) algorithm is proposed in this paper. can decompose into a series of components, each which be assumed as essentially Gaussian. original decomposed intrinsic functions (IMFs) final residual by using EMD first. Then, average period (Tm¯) corresponding energy densities (EDs) all IMFs are calculated. A suitable IMF selected relationship between EDs...

Full-waveform LiDAR systems have been developed owing to their superiority in terms of high precision and resolution. However, further improving the imaging speed resolution continues be a problem. In this study, we propose an optical orthogonal code division multiple access (OCDMA) coding 3D technique, non-scanning full-waveform system is first demonstrated. Encoding, multiplexing, decoding are essential modules OCDMA system, which use M detectors N-bits achieve high-accuracy decomposition...

In this paper, we propose a continuous wavelet transform and iterative decrement algorithm to decompose the light detection ranging (LiDAR) full-waveform echoes into series of components, each which can be assumed as Gaussian essentially. We calculate scale in real time according relationship between center frequency mother approximate transmitted laser pulse. The approximated is calculated half-width effective part positions model components precisely predicted maxima coefficient. And...

Abstract The full waveform decomposition technique is significant for LiDAR ranging. It challenging to extract the parameters from non-Gaussian shaped waveforms accurately. Many parametric models (e.g. Gaussian distribution, lognormal generalized normal Burr and skew-normal distribution) were proposed fit sharply-peaked, heavy-tailed, negative-tailed waveforms. However, these can constrain shape of components. In this article, convolution model established. Firstly, a set functions...

Рurpose. This paper analyzes the evolution process and cultural connotation of Qiang costume form, discusses application form elements in modern clothing design, provides a theoretical basis for innovative design national costumes. Methodology. The field research method, literature analysis case study method are used to analyze process, connotation, Results. By studying development style changes costumes, it is concluded that its unique characteristics closely related social characteristics,...

Scannerless laser three-dimensional (3D) imaging relies on large-scale detector arrays to achieve high-resolution and is one of the main technologies in light detection ranging (LIDAR). However, high production cost complex manufacturing process limiting resolution. In this paper, we demonstrate a subpixel 3D method based two-dimensional (2D) encoding decoding. First, an LED array projects 2D spatio-temporal coded beams onto target space. Accordingly, optical multiplexer separates...

Global navigation satellite system is indispensable to provide positioning, navigation, and timing information for pedestrians vehicles in location-based services. However, tree canopies, although considered as valuable city infrastructures urban areas, adversely degrade the accuracy of global positioning they attenuate signals. This article proposes a bagging tree-based pseudorange error prediction algorithm, by considering two variables, including carrier noise C/ N 0 elevation angle θ e...

A novel three-dimensional (3D) imaging lidar system which is based on a virtual instrument technique introduced in this paper. The main characteristics of the include: capability modeling 3D object accordance with actual one by connecting to geographic information (GIS), and building scene for experiment including simulation environment. environment consists four parts: laser pulse, atmospheric transport, target interaction, receiving unit. Besides, provides an interface on-site experiment....

In this letter, we propose a new modification to the belief propagation (BP) decoding algorithm for Finite-Geometry low-density parity-check (LDPC) codes. The is based on introducing feedback into iterative process, which can break oscillations of bit log-likelihood ratio (LLR) values. Simulations show that, with given maximum iteration, BP (FBP) achieve better performance than conventional algorithm.

The laser system's parameter fitting is an important step to the ranging and imaging, however, complexity of target object will cause waveform superimposed, some existing algorithms are difficult accurately obtain parameters, by decomposing into a series continuous can greatly improve accuracy.Considering algorithm, LM algorithm's accuracy depends on initial value easy be caught in local optima, if inaccurate then it get accurate results.The we use not standard Gaussian model reality,it...

The wind tunnel test was carried out for the Sightseeing Tower of West Taihu Lake, Changzhou in this study, and equivalent static loads Moon were obtained at different angles. Frequency-domain analysis performed to reveal wind-induced response dynamics. distribution diagram unfavorable worked provide reference design main structure.