To use monostatic based imaging algorithms for multireceiver synthetic aperture sonar, the conversion is often carried out on phase centre approximation, which widely exploited by SAS systems. This paper presents a novel aspect dealing with imagery, still depends idea of conversion. The approach in this Loffelds bistatic formula that consists two important terms, i.e., quasi and deformation terms. Our basic to preprocess term then incorporate into an analogous spectrum. With new spectrum,...

For a multi-hydrophone synthetic aperture sonar (SAS), the instability of platform and underwater turbulence easily lead to two-dimensional (2-D) space-variant (SV) motion errors. Such errors can cause serious imaging problems are very difficult compensate for. In this study, we propose 2-D SV compensation algorithm for SAS based on sub-beam compensation. The proposed is implemented using following four-step process: (1) error each obtained by substituting sonar’s parameters measured in...

The prediction of time series is an extremely important and challenging part, due to some other unavoidable external factors, it can also affect its results. Therefore, in order compare which model produce better predictions, this paper explores the following two models. First all, more traditional classical "Autoregressive Integrated Moving Average" (ARIMA). Moreover, according continuous exploration development over years, variables have evolved, such as SRIMA (seasonal ARIMA), etc. This...

In multireceiver synthetic aperture sonars (SASs), the traditional non-stop-hop-stop model normally ignores intrapulse motion of sonar platform. However, such brings Doppler scale effect (DSE) to echo signal, which will lead change in carrier frequency (CF) and modulation (FM) rate signal may eventually result image defocus. this article, considering motion, time-varying time delay range history SAS were derived by introducing into history, then was established. After approximating 2-D...

When a synthetic aperture sonar (SAS) system operates under low-frequency broadband conditions, the azimuth range coupling of point target reference spectrum (PTRS) is severe, and high-resolution imaging limited. To solve above issue, we first convert multi-receivers’ signal into equivalent monostatic then divide subblocks frequency subbands within each subblock in order. The terms are converted linear based on piece-wise approximation (PLA), phase error PTRS subband less than π/4. Then, use...

A hierarchical quality-guided phase unwrapping algorithm in a shared memory environment is proposed. First, the wrapped divided into regular blocks, and local wrap counts of every block are obtained by strategy. Then, gradient adjacent blocks quality defined boundary block. Each block's data can be regarded as an abstract point, strategy used again to solve each Finally, absolute point adding corresponding counts, then final unwrapped obtained. The performance proposed verified through...

Uncompensated motion errors can seriously affect the imaging quality of synthetic aperture sonars (SASs). In existing line-by-line compensation (MOCO) algorithms for wide-beam multiple-receiver SAS systems, approximate form range history error usually introduces a significant approximation error, and residual two-dimensional (2D) cell migration (RCM) caused by aperture-dependent is not corrected, resulting in severe defocus image. this paper, presence translational rotational system, exact...

Aiming at the problem that existing imaging algorithms under wide beam conditions only consider relative range offset between different receivers, ignoring differential curvature, resulting in poor quality conditions, this paper proposes a Doppler algorithm for synthetic aperture sonar with multiple receivers considers curvature. Firstly, Signals from are corrected to central reference receiver domain, and spectrum aliasing is removed through coherent superposition. The signal equivalent...

In existing imaging algorithms for wide-beam multiple-receiver synthetic aperture sonar (SAS) systems, the double-square-root (DSR) range history of each receiver is generally converted into sum a single-square-root (SSR) and an error term using displaced phase center (DPCA) approximation. Therefore, before imaging, receiver’s needs to be individually compensated in azimuth frequency domain, which computationally expensive. As result, novel SAS system algorithm with low complexity high...

Precise orientation information facilitates target recognition of sonar images. Traditional estimation methods, including the Hough transform method, have poor antinoise abilities, so they cannot achieve high precision for images, which usually low signal-to-noise ratios. The convolutional neural network (CNN) regression method is sensitive to image affine transformations and requires extensive computation, it strong robustness or speed. To high-precision, high-speed, robust targets, we...

A correction approach for the inclined array of hydrophones is proposed to prevent decline image quality in SAS. In this approach, 2-way exact acoustic propagation path transformed into sum a single root term and an offset term, where ideal contains all errors cause by array. The separated two steps: phase delay correction. performed on echo signal each receiving hydrophone 2-D time domain multiplication range frequency with linear function at reference range. Finally, effectiveness examined...

The existing imaging algorithms for the multiple‐hydrophone synthetic aperture sonar (SAS) cannot obtain a good result in moderate squint case where angle is from 10° to 20°, because they do not take differential range curvature into account, and methods of equivalent spatial sampling work well. This study proposes an algorithm SAS. First, history model SAS established. Second, signal each hydrophone processed separately with bistatic correct curvature. Third, corrected shifted same bin...

Phase unwrapping is a key step during the signal processing of interferometric synthetic aperture radar (InSAR) data. The precision and efficiency are two problems phase unwrapping. path-following algorithm usually has high computational efficiency, but low quality areas prone to have accumulated errors. global optimization can effectively suppress error propagation by introducing weights, efficiency. This paper presents combined based on guided minimum discontinuity algorithm, which...

Phase unwrapping is a very important process in the digital elevation model(DEM) rebuilding of imaging area from its interferometric phase data. This paper presents fast algorithm based on minimum discontinuity optimization, which greatly enhances efficiency compared with original proposed by Flynn. To accelerate optimization process, preprocessing used to get an initial wrap count least-squares method. For that unweighted problem can be solved FFT-based method, wrapped obtained quickly....

In synthetic aperture imaging, the interpulse Doppler shift is commonly used, while intrapulse ignored. However, for linear frequency modulation signal, can cause an additional range cell migration (ARCM) and a phase error term. Additionally, ARCM may exceed resolution in certain cases of multireceiver sonar (SAS), which will result image defocus. Therefore, SAS should not be ignored such cases. this study, condition negligible presented, that is, moving distance platform within pulse much...

The low efficiency of complex image registration has become a key problem for the signal processing interferometric synthetic aperture sonar (InSAS). In this paper, collaborative method based on CPU/GPU is proposed, which provides new realtime InSAS. steps coarse registration, salve interpolation and wrapped phase extraction are mapped to graphics unit (GPU) executed respectively. refine polynomial coefficient fitting still CPU. test performed real InSAS data confirms validity proposed method.

Convolutional neural network (CNN) has achieved good performance in object classification due to its inherent translation equivariance, but ability of scale equivariance is poor. A Scale-Aware Network (SA Net) with proposed, which can estimate scale, that is, the size image, while classifying. In training stage, only one pattern learned. testing firstly, sample unseen zoomed-in and zoomed-out into a set images different scales, form an image pyramid. The zooming-in channels are up-sampled by...

The effectiveness of CycleGAN is demonstrated to outperform recent approaches for semisupervised semantic segmentation on public benchmarks. In contrast analog images, however, the acoustic images are unbalanced and often exhibit speckle noise. As a consequence, prone mode-collapse cannot retain target details when applied directly sonar image dataset. To address this problem, spectral normalized network presented, which applies normalization both generators discriminators stabilize training...

The effectiveness of CycleGAN is demonstrated to outperform recent approaches for semi-supervised semantic segmentation on public benchmarks a small number the labelled data. However tends generate same results acoustic image datasets, and can't retain target details. To solve this problem, an spectral normalized network (SNCycleGAN) presented, which applies normalization both generators discriminators stabilize training GANs. experimental demonstrate that SNCycleGAN helps achieve reasonably...

Urban scene modeling is a promising research subject, for it plays an important role in the areas of national defense, transportation, urban planning, and entertainment industries. Researchers have been looking forward to breakthroughs improving level photorealism performance. This paper discusses implementation simulation certain parts city scene. We use graphics mixed generate variety architectural models. Graphics hybrid method 3D models given objects by conducting image processing...