underwater mapping

Underwater mapping 2025 - Part A

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23 - Cooperative SLAM Algorithm for Multi-AUV Underwater Exploration and Mapping

Author: Rongren Wu SLAM (Simultaneous Localisation and Mapping) is crucial for mapping unknown deep-sea areas. This paper suggests an AUV cluster SLAM algorithm to enhance mapping efficiency. It has three parts: (1) a multi-beam sonar image processing algorithm that filters dynamic points and redundant information; (2) SLAM using data from DVL, IMU, and DM based on a Rao-Blackwellised particle filter; and (3) an iUSBL system for cooperative positioning of AUVs. This algorithm significantly improves mapping efficiency and stabilizes SLAM performance by reducing errors from dynamic points.

22 - An overview of industrial image segmentation using deep learning models.

Authors: Guina Wang, Zhen Li, Guirong Weng, Yiyang Chen Image segmentation is important in AI and computer vision, used for tasks like industrial picking and video surveillance. This review covers traditional and deep learning segmentation algorithms, including their integration. It discusses various label frameworks and compares methods on benchmark datasets. Lastly, it addresses challenges and opportunities for future research.

01 - Remote Awareness of Image Quality for Multi-week Shore- launched AUV Surveys

Authors: Adrian Bodenmann, Daniel O.B. Jones, Alexander B. Phillips, Robert Templeton, Rashiid Sherif, Francesco Fanelli, Darryl Newborough, and Blair Thornton Visual seafloor imaging using autonomous underwater vehicles (AUVs) is now a common method for mapping and monitoring. This research creates a new way to assess image quality on-site during a 21-day AUV campaign. AUV operators received quality scores via satellite to improve data collection.

04 - Sound Absorption of the Water Column and Its Calibration for Multibeam Echosounder Backscattered Mapping in the East Sea of Korea

Authors: Seung-Uk Im, Cheong-Ah Lee, Moonsoo Lim, Changsoo Kim, and Dong-Guk Paeng This study uses Korea Oceanographic Data Center) datasets to analyze and visualize spatiotemporal variations in underwater sound absorption in the East Sea of Korea. The calibration process revealed discrepancies of up to 2.1 dB in backscatter intensity across survey lines, highlighting potential misrepresentation of legacy Multibeam echosounder (MBES) data due to site-specific absorption variability. This integrated approach enhances the reliability of legacy MBES data and provides valuable insights for marine resource management and environmental monitoring.

05 - Underwater DVL Optimization Network (UDON): A Learning- Based DVL Velocity Optimizing Method for Underwater Navigation

Authors: Feihu Zhang, Shaoping Zhao, Lu Li, and Chun Cao This paper proposes an end-to-end deep-learning approach to improve the accuracy of Doppler Velocity Log (DVL) velocity vector measurements for autonomous underwater vehicles (AUVs) that uses raw measurement data from an Inertial Measurement Unit (IMU) to assist DVL in velocity vector estimation and refining it towards the Global Positioning System (GPS). The research results show that the proposed method can achieve a maximum improvement of 69.26% in root mean square error and 78.62% in relative trajectory error in DVL vector predictions.

06 - Secrecy capacity maximization in autonomous underwater vehicle-enabled underwater acoustic sensor networks

Authors: Xufei Ding, Wen Tian, Xin Sun This study examines covert data collection in autonomous underwater vehicles (AUVs) for underwater acoustic sensor networks (UASNs). The researchers propose an efficient iterative optimization algorithm to optimize USN scheduling and AUV routes, aiming to maximize secrecy capacity under constraints such as AUV trajectory, USN scheduling, connection outage probability, and secrecy outage probability.

07 - Enhancing Physical Spatial Resolution of Synthetic Aperture Sonar Images Based on Convolutional Neural Network

Authors: Pan Xu, Dongbao Gao, Shui Yu, Guangming Li, Yun Zhao, and Guojun Xu This deep learning method is used to improve the physical spatial resolution of underwater sonar images using a proposed U-shaped end-to-end neural network, which includes down-sampling and up-sampling parts. This method reduces normalized loss on testing sets and improves the accuracy of predicted high-resolution images. This trained network can map high-resolution targets to impulse responses, providing a practical alternative for underwater target detection..

08 - Underwater Target Detection with High Accuracy and Speed Based on YOLOv10

Authors: Zhengliang Hu, Le Cheng, Shui Yu, Pan Xu, Peng Zhang, Rui Tian, and Jingqi Han This study presents an underwater target detection method based on YOLOv10 (You Only Look Once v10), which outperforms the YOLOv5 model in terms of detection accuracy and speed. The YOLOv10 model has a mAP50 (Average Precision at an Intersection over Union threshold of 50%) of 85.6% on the URPC 2020 (Underwater Robot Picking Contest 2020) dataset, a 1.2% improvement from YOLOv5, demonstrating its potential for precise and fast underwater target detection.

09 - Side-Scan Sonar Small Objects Detection Based on Improved YOLOv11

Authors: Chang Zou, Siquan Yu, Yankai Yu, Haitao Gu, and Xinlin Xu The study proposes an improved YOLOv11 (You Only Look Once v11) network called YOLOv11-SDC for underwater object detection using side-scan sonar. It includes a new Sparse Feature module, a Dilated Reparam Block, a Control Module, and a Content-Guided Attention Fusion module. The improved method outperforms previous versions in detection performance.

10 - A Deep Shrinkage Network for Direction-of-Arrival Estimation with Sparse Prior

Authors: Lei Zhou, Shihong Zhou, Yubo Qi, Lixin Wu, and Yannick Benezeth This study proposes a deep learning-based framework for estimating Direction-of-arrival (DOA) in underwater multipath signals. It uses sparse representation and a super-resolution deep shrinkage reconstruction network (SDSR-Net) to map the sparse representation of the covariance matrix to the DOA. Simulations and evaluations show that the proposed method significantly improves DOA estimation accuracy.

11 - An Improved YOLOv9s Algorithm for Underwater Object Detection

Authors: Shize Zhou, Long Wang, Zhuoqun Chen, Hao Zheng, Zhihui Lin, and Li He The YOLOv9s-SD (You Only Look Once 9s-SD) underwater target detection algorithm aims to improve underwater object detection performance by combining MobileNetV2's (MobileNetV2 is a convolutional neural network architecture designed for mobile and embedded vision applications) inverted residual structure with Simple Attention Module and Squeeze-and-Excitation Attention. Experiments show improvement in mean Average Precision, demonstrating better adaptability to intricate underwater environments.

12 - Advancing Seabed Bedform Mapping in the Kuznica Deep: Leveraging Multibeam Echosounders and Machine Learning for Enhanced Underwater Landscape Analysis

Authors: Lukasz Janowski This study focuses on the development of an automatic seabed mapping methodology using multibeam echosounders and machine learning, integrating various scientific fields to understand the underwater landscape, addressing sediment composition, backscatter intensity, and geomorphometric features. It emphasizes using fewer, carefully selected features for training models, improving accuracy and robustness.

13 - Real-Time Registration of 3D Underwater Sonar Scans

Authors: António Ferreira, José Almeida, Aníbal Matos, and Eduardo Silva This article presents a collection of generic matrix manipulation kernels for parallelized perception applications. It discusses a parallel implementation for the 3DupIC algorithm, a probabilistic scan matching method for sonar scan registration. Tests show the algorithm's real-time performance, enabling 3D sonar scan matching to be executed onboard the EVA AUV.

14 - Multi-Scale Feature Enhancement Method for Underwater Object Detection

Authors: Mengpan Li, Wenhao Liu, Changbin Shao, Bin Qin, Ali Tian, and Hualong Yu This paper presents a Multi-Scale Feature Enhancement (MSFE) method to address challenges in underwater object detection, aiming to achieve dual multi-scale information integration through the internal structural design of the basic C2F module (a module that converts convolutional outputs into structured features) in the Backbone network and the external global design of the feature pyramid network (FPN). The method uses a module to address fine-grained feature vanishing and injects a shallow feature branch to enhance information integration between inter-layer features.

20 - The Method for Storing a Seabed Photo Map of the During Surveys Conducted by an Autonomous Underwater Vehicle

Authors: Chang Liu, Vladimir Filaretov, Eduard Mursalimov, Alexander Timoshenko, and Alexander Zuev This paper presents a new method for creating a photographic map of the seabed using images captured by autonomous underwater vehicles' photo and video systems, stored in a mosaic format, allowing for automatic search and recognition of underwater objects. The authors emphasize the efficiency of the method, which forms the map directly during the vehicle's movement, using only the onboard computer's computing power. Its algorithm for saving the map in mosaic format, used in interactive geographic maps like Google Maps, reduces read and write operations, ensuring timely operation.

21 - AUV Online Path Planning Strategy Based on Sectorial Gridded Detection Area

Authors: Yang Liu, Jinxi Sun, Guojie Li, and Xiujun Xu This study proposes an online path planning strategy for an autonomous underwater vehicle using forward- looking sonar in unknown environments. It divides the sonar fan-shaped detection area into multiple grids and uses a comprehensive cost function for optimal heading. This strategy ensures safe and smooth navigation in obstructed areas and narrow passages.

31 - Lightweight Underwater Target Detection Algorithm Based on YOLOv8n

Authors: Dengke Song and Hua Huo The RDL-YOLO is a lightweight detection algorithm designed to tackle challenges in underwater target detection, including complex environments, image blurring, and high model parameter counts that incorporates optimizations. Experimental results show an average precision increase of 1.4% and 1.0%, respectively, while reducing parameter count and computational complexity by 19.3% and 14.8%.

32 - Persistent Localization of Autonomous Underwater Vehicles Using Visual Perception of Artifi cial Landmarks

Authors: Jongdae Jung, Hyun-Taek Choi, and Yeongjun Lee This paper proposes a visual landmarks-based simultaneous localization and mapping (SLAM) system for autonomous underwater vehicles (AUVs). The system uses two types of underwater landmarks observed using forward and downward-looking cameras. The information, along with incremental DR estimates, is integrated within the extended Kalman filter (EKF) SLAM approach.

33 - SDA-Mask R-CNN: An Advanced Seabed Feature Extraction Network for UUV

Authors: Yao Xiao, Dongchen Dai, Hongjian Wang, Chengfeng Li, and Shaozheng Song The paper introduces a novel framework for precise seabed terrain edge feature extraction from Side-Scan Sonar (SSS) images, enhancing Unmanned Underwater Vehicle (UUV) perception and navigation. This framework addresses challenges in underwater image analysis, including low segmentation accuracy and ambiguous edge delineation. It incorporates a Structural Synergistic Group-Attention Residual Network, a Depth-Weighted Hierarchical Fusion Network, and an Adaptive Synergistic Mask Optimization strategy.

34 - A Holistic High-Resolution Remote Sensing Approach for Mapping Coastal Geomorphology and Marine Habitats

Authors: Evagoras Evagorou, Thomas Hasiotis, Ivan Theophilos Petsimeris, Isavela N. Monioudi, Olympos P. Andreadis, Antonis Chatzipavlis, Demetris Christofi, Josephine Kountouri, Neophytos Stylianou, Christodoulos Mettas, Adonis Velegrakis, and Diofantos Hadjimitsis This research demonstrates how satellite, aerial, terrestrial, and marine remote sensing techniques can be integrated to produce accurate information, revealing significant elevation and shoreline changes over one year, highlighting coastal zone dynamics. This highlights the importance of incorporating information from all available sensors for complete geomorphological and marine habitat mapping for sustainable coastal management strategies.

36 - Model-Based AUV Path Planning Using Curriculum Learning and Deep Reinforcement Learning on a Simplifi ed Electronic Navigation Chart

Authors: Lukasz Marchel, Rafał Kot, Piotr Szymak, and Paweł Piskur This paper evaluates reinforcement learning (RL)-based methods for autonomous underwater vehicles (AUVs) trajectory planning. It incorporates a full motion model and proposes a reward function to elicit desired behaviors. The models are trained on simplified ENC maps and compared against five classical methods. The proposed solution enables efficient, collision-free route planning.

37 - Depth Estimation of an Underwater Moving Source Based on the Acoustic Interference Pattern Stream

Authors: Lintai Rong, Bo Lei, Tiantian Gu, and Zhaoyang He This study proposes an interference feature fusion (IFF) method for underwater maneuvering sources in deep oceans that extracts the principal interference mode of the VTR and constructs a depth ambiguity function. This method achieves long-term depth estimation and recognition of underwater sources without environmental information. It can suppress false peaks and reduce depth estimation errors by at least 47% compared to the generalized Fourier transform method.

38 - Underwater Side-Scan Sonar Target Detection: An Enhanced YOLOv11 Framework Integrating Attention Mechanisms and a Bi-Directional Feature Pyramid Network

Authors: Junhui Zhu, Houpu Li, Min Liu, Guojun Zhai, Shaofeng Bian, Ye Peng, and Lei Liu Underwater target detection is crucial for marine exploration, but faces challenges due to the complex underwater environment. The ABFP-YOLO model addresses these issues by integrating a bi-directional feature pyramid network and an attention module. It effectively recognizes targets of varying scales, especially small ones, in complex scenarios. Experiments on two datasets show the model achieves mean average precision scores of 0.988 and 0.866, indicating superior performance in complex underwater environments.

39 - Oscillatory Forward-Looking Sonar Based 3D Reconstruction Method for Autonomous Underwater Vehicle Obstacle Avoidance

Authors: Hui Zhi, Zhixin Zhou, Haiteng Wu, Zheng Chen, Shaohua Tian, Yujiong Zhang, and Yongwei Ruan This study proposes a cost-effective 3D reconstruction method for autonomous underwater vehicle inspection in 3D environments that uses an oscillatory forward-looking sonar with a pan-tilt mechanism, extending perception from a 2D plane to a 75-degree spatial range. The system integrates with the Ego-Planner path planning algorithm and nonlinear Model Predictive Control algorithm, achieving 100%, 60%, and 30% obstacle avoidance success rates under localization errors.

40 - Three-Dimensional Localization of Underwater Nodes Using Airborne Visible Light Beams

Authors: Jaeed Bin Saif, Mohamed Younis, and Fow-Sen Choa This paper proposes a novel localization method using visible light communication (VLC) from an airborne unit to locate underwater nodes, which uses VLC transmissions towards the water surface, encoded with GPS coordinates. Existing techniques assume depth measurements, but this method uses VLC signals to estimate the underwater node's 3D position. Extensive simulations validate the method's effectiveness and performance across various parameters.

41 - Underwater SLAM Meets Deep Learning: Challenges, Multi- Sensor Integration, and Future Directions

Authors: Mohamed Heshmat, Lyes Saad Saoud, Muayad Abujabal, Atif Sultan, Mahmoud Elmezain, Lakmal Seneviratne, and Irfan Hussain This survey analyzes the latest developments in deep learning-enhanced simultaneous localization and mapping (SLAM) for underwater applications, categorizing approaches based on methodologies, sensor dependencies, and integration with deep learning models, highlighting the benefits and limitations of existing techniques, key innovations, and unresolved challenges. It also introduces a novel classification framework for underwater SLAM based on its integration with underwater wireless sensor networks (UWSNs), enhancing localization, mapping, and real-time data sharing among AUVs.

42 - Underwater-Image Enhancement Based on Maximum Information-Channel Correction and Edge-Preserving Filtering

Authors: Wei Liu, Jingxuan Xu, Siying He, Yongzhen Chen, Xinyi Zhang, Hong Shu, and Ping Qi The authors propose an underwater-image enhancement (UIE) approach to address issues like color distortion and reduced contrast in underwater images. They use maximum information-channel compensation and edge- preserving filtering techniques to improve color quality. This approach involves enhancing the color-corrected image, generating globally contrast-enhanced images, and decomposing the enhanced image into low- frequency and high-frequency components.

47 - Task Allocation and Path Planning Method for Unmanned Underwater Vehicles

Authors: Feng Liu, Wei Xu, Zhiwen Feng, Changdong Yu, Xiao Liang, Qun Su, and Jian Gao This study proposes a task allocation and path planning method for Unmanned Underwater Vehicles (UUVs) to improve their autonomous navigation and adaptability in complex marine environments, using an Improved Grey Wolf Algorithm (IGWA) and a Circle chaotic mapping strategy to optimize task allocation and search efficiency. An algorithm termed GR-RRT is employed for path planning, ensuring obstacle avoidance and reducing redundant sampling. Experimental results show significant advantages in task completion rate and path optimization efficiency.

48 - YOLO-NeRFSLAM: underwater object detection for the visual NeRF-SLAM

Authors: Zhe Wang, Zhibin Yu, and Bing Zheng This paper proposes a new underwater Simultaneous Localization and Mapping (SLAM) framework that combines neural radiance fields (NeRF) with a dynamic masking module. The Marine Motion Fusion (MMF) strategy screens out dynamic objects, maintaining stable camera pose estimation and pixel-level dense reconstruction. Specialized loss functions cope with light attenuation and the dynamic nature of underwater scenes. Experimental results show that the method reduces localization drift, improves dense mapping accuracy, and achieves favorable runtime efficiency in multiple real underwater video datasets.

49 - Visual-Based Position Estimation for Underwater Vehicles Using Tightly Coupled Hybrid Constrained Approach

Authors: Tiedong Zhang, Shuoshuo Ding, Xun Yan, Yanze Lu, Dapeng Jiang, Xinjie Qiu, and Yu Lu This paper introduces a hybrid monocular visual Simultaneous Localization and Mapping (SLAM) system for unmanned underwater vehicles (UUVs), featuring a robust three-step tracking strategy. The system uses a feature-based method for rough pose estimation, a direct method for refining it, and a tightly coupled visual hybrid optimization method for stable tracking.

50 - Robust Forward-Looking Sonar-Image Mosaicking Without External Sensors for Autonomous Deep-Sea Mining

Authors: Xinran Liu, Jianmin Yang, Changyu Lu, Enhua Zhang, and Wenhao Xu This study introduces a robust Forward-Looking Sonar (FLS) image mosaicking framework for real-time environmental mapping in deep-sea mining vehicles (DSMV). This model integrates bidirectional cyclic consistency filtering with a soft-weighted feature refinement strategy and proposes a radial adaptive fusion algorithm for image fusion. The experimental results show high robustness and accuracy under real deep-sea conditions, supporting tasks like path planning, obstacle avoidance, and simultaneous localization and mapping, enabling reliable perceptual capabilities for intelligent underwater operations.

51 - Leveraging learned monocular depth prediction for pose estimation and mapping on unmanned underwater vehicles

Authors: Marco Job, David Botta, Victor Reijgwart, Luca Ebner, Andrej Studer, Roland Siegwart, and Eleni Kelasidi The paper introduces a framework that uses visual and acoustic sensor data to improve localization and mapping in complex underwater environments, particularly in fish farming. It enables net-relative pose estimation for Unmanned Underwater Vehicles (UUVs) and depth prediction using deep learning and sparse depth priors. This framework can generate detailed 3D maps in real- time, proving accurate for autonomous navigation and inspection.

52 - Direct Forward-Looking Sonar Odometry: A Two-Stage Odometry for Underwater Robot Localization

Authors: Wenhao Xu, Jianmin Yang, Jinghang Mao, Haining Lu, Changyu Lu, and Xinran Liu This paper proposes a lightweight front-end, forward- looking Sonar (FLS) odometry (DFLSO) for underwater robots, aiming to provide fast and accurate localization. It uses forward-looking sonar (FLS) images for pose estimation, extracting point clouds, and matching images. It also uses an image processing method to generate a 3- D point cloud, and a lightweight keyframe system to construct submaps, validated through simulation experiments and sea trials.

03 - Geomorphic time series reveals the constructive and destructive history of Havre caldera volcano, Kermadec arc

Authors: E. Spain, R. J. Carey, J. M. Whittaker, V. L. Lucieer, J. M. Fox, S. J. Watson, and F. Caratori Tontini This article examines geomorphic changes at the submarine Havre volcano over a 13-year period using a combination of bathymetric surveys and remotely operated vehicle (ROV) observations. By integrating various data sources, the study identifies four geomorphic groups and develops detailed maps that reveal volcanic features and processes. Notably, the study uncovers a significant underestimation of the scale of cryptodome emplacement related to the 2012 eruption and extends the timeline for volcanic product emplacement to a maximum of 3 years post-eruption. Overall, the research highlights ongoing seafloor modifications long after volcanic eruptions have occurred.

27 - Side-Scan Sonar Image Classification Based on Joint Image Deblurring–Denoising and Pre-Trained Feature Fusion Attention Network

Authors: Baolin Xie, Hongmei Zhang, and Weihan Wang This article discusses advancements in deep learning models for classifying side-scan sonar (SSS) images, focusing on addressing common challenges such as noise interference and limited dataset sizes. It introduces a novel classification model that combines joint image deblurring and denoising techniques with a pre-trained attention network. By leveraging advanced feature extraction methods and attention mechanisms, the model significantly improves classification accuracy and interpretability, achieving a notable accuracy rate of 96.80% on a dedicated dataset.

30 - A novel use of Stereo Baited Remote Underwater Video and Drop-Down Video for biodiversity and marine landscape mapping and prediction

Authors: Natasha L. Walker-Milne, Sophie Elliott, Peter J. Wright, & David M. Bailey This paper discusses the significance of benthic mapping in managing marine resources and restoring biodiversity, particularly through the analysis of patch- and landscape- level processes affecting marine species. The study utilizes Stereo Baited Remote Underwater Video (SBRUV) and Drop-Down Video (DDV) surveys conducted in the South Arran Marine Protected Area from 2013 to 2019. Through these surveys, a comprehensive dataset was generated to create detailed benthic maps that enhance understanding of substratum distribution and associated epibenthic biodiversity. The findings aim to improve management strategies for Marine Protected Areas by identifying areas of high biodiversity.

02 - Sequential Multimodal Underwater Single-Photon Lidar Adaptive Target Reconstruction Algorithm Based on Spatiotemporal Sequence Fusion

Authors: Tian Rong, Yuhang Wang, Qiguang Zhu, Chenxu Wang, Yanchao Zhang, Jianfeng Li, Zhiquan Zhou, and Qinghua Luo This paper presents a sequential multimodal underwater single-photon LiDAR adaptive target reconstruction algorithm based on spatiotemporal sequence fusion, designed for long-range, high-resolution imaging of slow- moving small underwater targets. The method comprises three stages: data preprocessing, sequence-optimized extreme value inference filtering, and collaborative variation–based image optimization—enabling robust extraction of depth and reflectivity from sparse, noisy photon echoes.

18 - Evaluating the Applications and the Growing Importance of Autonomous Underwater Vehicles (AUVs) in Marine Geophysical Survey

Authors: Obembe O. Elijah & Ali O. Barnabas Autonomous Underwater Vehicles (AUVs) are versatile, vessel-independent platforms widely used in marine geoscience, oceanography, defense, industry, and policy. They excel in extreme environments, such as deep hydrothermal vents and under polar ice, delivering high- resolution, accurate seafloor mapping data surpassing surface vessel capabilities, especially in the deep sea. This review emphasizes their growing role in geophysical surveys, particularly in acquiring electric and magnetic field data for subsea infrastructure inspection, self-potential studies, and controlled-source electromagnetic surveys. comprehensive vector electromagnetic measurements.

19 - How Accurate Can 2D LiDAR Be? A Comparison of the Characteristics of Calibrated 2D LiDAR Systems

Authors: Adam Ziebinski, and Piotr Biernacki 2D LiDAR measurements often lack the precision required to accurately determine the motion range or recalibrate the position of Autonomous Guided Vehicles (AGVs). To address this, this article proposes a multi-sectional calibration (MSC) method with median filtration (MF) to improve measurement accuracy. By dividing the measurement range into sections and optimizing the MF window width, the method enhances sensitivity to deviations and improves distance measurement accuracy by up to 89%. Experiments confirm its significant impact on the precision and accuracy of 2D LiDAR systems.

24 - Empirical Quantification of Topobathymetric Lidar System Resolution Using Modulation Transfer Function

Author: K. W. Sacca, and J. P. Thayer Topobathymetric scanning lidar on unmanned aircraft systems enables high-resolution mapping of terrain and underwater interfaces but lacks standardized empirical resolution validation methods. Theoretical models often fail to account for instrument, platform, or environmental uncertainties, particularly in bathymetry where water conditions significantly impact performance. To address this, the study extends modulation transfer function (MTF) methods, traditionally used for passive imaging, to active scanning lidar by employing compact retroreflectors as calibration targets. These targets facilitate empirical resolution assessment using height data alone, independent of intensity measurements.

25 - Semantic segmentation of underwater images based on the improved SegFormer

Authors: Bowei Chen, Wei Zhao, Qiusheng Zhang, Mingliang Li, Mingyang, and You Tang This study proposes an enhanced semantic segmentation model for underwater images, built upon SegFormer. Key improvements include replacing the Mix Transformer backbone with Swin Transformer for better global context modeling, integrating Efficient Multi-scale Attention (EMA) in both backbone and decoder to capture multi-scale features, and adding a Feature Pyramid Network (FPN) to the decoder for robust multi-resolution feature fusion.

26 - Color correction methods for underwater image enhancement: A systematic literature review

Authors: Yong Lin Lai, Tan Fong Ang, Uzair Aslam Bhatti, Chin Soon Ku, Qi Han, Lip Yee Por This systematic review analyzes 67 studies (2010–2024) on underwater image color correction, categorizing 13 methods into physical models (light attenuation/scattering simulation), non-physical models (pixel-level manipulation without physical modeling), and deep learning-based methods (data-driven enhancement). While each approach has strengths, common challenges include algorithmic limitations, data dependency, high computational cost, and inconsistent performance across varied underwater conditions. The review provides a unified taxonomy, identifies key research gaps, and stresses the need for more adaptable, computationally efficient solutions.

28 - Hyperspectral LiDAR for Subsea Exploration: System Design and Performance Evaluation Method

Authors: Huijing Zhang, Linsheng Chen, Haohao Wu, Mei Zhou, Jiuying Chen, Zhichao Chen, Jian Hu, Yuwei Chen, Jinhu Wang, Yifang Niu, Meisong Liao, Xiaoxing Wang, Wanqiu Xu, Tianxing Wang, and Shizi Yu his study introduces an advanced underwater hyperspectral LiDAR (UDHSL) system operating from 450–700 nm, with adjustable spectral bandwidth (10–300 nm) and repetition rate (50 kHz–1 MHz). It achieves high precision (≤1 mrad divergence, 7 ns pulse width, 7.5 µJ energy, 1.13 cm ranging resolution, 1.02 m accuracy at 27 m).

29 - Detailed Investigation of Cobalt-Rich Crusts in Complex Seamount Terrains Using the Haima ROV: Integrating Optical Imaging, Sampling, and Acoustic Methods

Authors: Yonghang Li, Huiqiang Yao, Zongheng Chen, Lixing Wang, Haoyi Zhou, Shi Zhang, and Bin Zhao The Haima 4500-m-class ROV is a critical deep-sea tool, offering long-duration power, adaptability, and safety for scientific and engineering missions. Equipped with advanced systems, including positioning, multi-angle cameras, manipulators, drills, samplers, and acoustic gauges, it efficiently surveys cobalt-rich crusts (CRCs) on rugged seamounts and has demonstrated high reliability, validating its capability for complex CRC surveys and supporting future resource assessments. Future improvements will focus on high-precision navigation, improved crust-thickness accuracy, higher imaging resolution, and AI-driven recognition.

35 - Selecting the best habitat mapping technique: a comparative assessment for fisheries management in Exmouth Gulf

Authors: Scott N. Evans, Nick Konzewitsch, Renae K. Hovey, Gary A. Kendrick, and Lynda M. Bellchambers A spatially explicit understanding of marine benthic habitats is critical for sustainable marine resource management, yet selecting the best mapping approach, especially in turbid or remote areas, remains difficult. This study in Western Australia’s Exmouth Gulf Prawn Managed Fishery compared four standard mapping techniques: satellite remote sensing, acoustic sounding, predictive modelling, and geostatistical interpolation, all validated through ground-truthing and confidence assessments. Geostatistical kriging proved most robust, offering the highest accuracy, quantifiable confidence, and detailed seasonal habitat maps.

43 - Multimodal fusion image enhancement technique and CFEC- YOLOv7 for underwater target detection algorithm research

Authors: Xiaorong Qiu, and Yingzhong Shi Underwater environments cause severe static and dynamic blurring in images, degrading target recognition accuracy. To address this, the authors propose an adaptive color compensation algorithm and an improved Multi-Scale Retinex (MSR) method for static blur, while using the Restormer network to mitigate dynamic blur from factors like camera shake. The effectiveness of these enhancements is validated through qualitative, quantitative analysis, and underwater target detection.

44 - Design and comparative analysis of laser-based array systems for UAV detection in surveillance zones

Authors: Meriem Salhi, Maha Sliti, Noureddine Boudriga, Abdelrahman Elfikky, Sarra Ayouni UAV detection is essential for safeguarding critical infrastructure, and LiDAR stands out among detection methods due to its high-resolution 3D mapping and accurate ranging capabilities across diverse environments. This study introduces two novel LiDAR-based UAV detection systems: (1) a multi-array static LiDAR with spherical arrangement of laser sources and optical concentrators feeding reflected energy to a central photodiode—enabling continuous, low-latency, wide-area coverage; and (2) a compact, energy-efficient one-array rotating LiDAR that trades off mechanical durability and scanning speed for cost-effectiveness.

45 - Enhancing Underwater LiDAR Accuracy Through a Multi- Scattering Model for Pulsed Laser Echoes

Authors: Ruichun Dong, Xin Fang, Xiangqian Meng, Chengyun Yang, & Tao Li This study introduces a Monte Carlo-based mathematical model for airborne LiDAR bathymetry to address the inaccuracy caused by neglecting multiple scattering events in conventional processing. The model simulates laser propagation through water, accounting for these scattering events using the Beer-Lambert law and the H-G phase function. Unlike existing research that focuses on laser emission, this work analyzes the probability of light reception in LiDAR returns. Results show that incorporating three or more scattering events significantly improves detection accuracy: by approximately 7% at 10m depth and 15-33% at 50m depth, thereby enhancing the efficiency of experimental systems.

46 - Spaceborne LiDAR Systems: Evolution, Capabilities, and Challenges

Authors: Jan Bolcek, Mohamed Barakat A. Gibril, Jirí Veverka, Šimon Sloboda, Roman Maršálek, and Tomáš Götthans This paper reviews space-borne LiDAR instruments, highlighting their evolution, capabilities, and contributions to Earth observation. It examines high-level LiDAR design, components, and operational parameters, and illustrates their role in studying environmental and atmospheric phenomena through select space missions. The paper also explores the ongoing development of advanced LiDAR technologies for future applications.

15 - A USBL/DR underwater integrated positioning method based on the cubature particle filter

Authors: Zicheng Dou, Chengming Luo, Hongxuan Fan, Zizhuo Liu, and Han Xu This paper presents a USBL/DR integrated navigation method using cubature particle filter (CPF) for underwater vehicles in complex environments. The system combines ultra-short baseline (USBL) positioning with Doppler velocity log (DVL) dead reckoning on an autonomous underwater vehicle (AUV). CPF addresses particle degradation issues inherent in standard particle filters during data fusion. Testing via simulation and lake trials demonstrated that this hybrid approach achieves superior positioning accuracy compared to conventional particle filter (PF) and unscented particle filter (UPF) methods.

16 - MUFFNet: lightweight dynamic underwater image enhancement network based on multi-scale frequency

Authors: Dechuan Kong, Yandi Zhang, Xiaohu Zhao, Yanqiang Wang, and Lei Cai Underwater robots' basic cameras yield blurry images that hinder marine exploration. MUFFNet addresses this via multi-scale frequency analysis, incorporating frequency- domain convolutional attention, Multi-Scale Enhancement Prior, Information Flow Interaction, and Multi-Scale Joint Loss. Experiments show it outperforms state-of-the-art models with lower compute and closer human visual alignment.

17 - Modeling of underwater vehicle positioning accuracy assessment based on ultrashort baseline

Authors: Zizhuo Liu, Chengming Luo, Hongxuan Fan, Zicheng Dou, and Han Xu To assess underwater vehicle positioning accuracy in complex and uncertain environments, this paper proposes a method to recursively derive an improved posterior Cramer-Rao lower bound for nonlinear measurement equations in ultrashort baseline acoustic sensors. Simulation results confirm the method's effectiveness, establishing the improved bound as a reliable evaluation standard for underwater vehicle filter estimates.