Marine GeodesyPub Date : 2022-07-05DOI: 10.1080/01490419.2022.2091696
Y. Lumban-Gaol, K. Ohori, R. Peters
{"title":"Extracting Coastal Water Depths from Multi-Temporal Sentinel-2 Images Using Convolutional Neural Networks","authors":"Y. Lumban-Gaol, K. Ohori, R. Peters","doi":"10.1080/01490419.2022.2091696","DOIUrl":"https://doi.org/10.1080/01490419.2022.2091696","url":null,"abstract":"Abstract Satellite-Derived Bathymetry (SDB) can be calculated using analytical or empirical approaches. Analytical approaches require several water properties and assumptions, which might not be known. Empirical approaches rely on the linear relationship between reflectances and in-situ depths, but the relationship may not be entirely linear due to bottom type variation, water column effect, and noise. Machine learning approaches have been used to address nonlinearity, but those treat pixels independently, while adjacent pixels are spatially correlated in depth. Convolutional Neural Networks (CNN) can detect this characteristic of the local connectivity. Therefore, this paper conducts a study of SDB using CNN and compares the accuracies between different areas and different amounts of training data, i.e., single and multi-temporal images. Furthermore, this paper discusses the accuracies of SDB when a pre-trained CNN model from one or a combination of multiple locations is applied to a new location. The results show that the accuracy of SDB using the CNN method outperforms existing works with other methods. Multi-temporal images enhance the variety in the training data and improve the CNN accuracy. SDB computation using the pre-trained model shows several limitations at particular depths or when water conditions differ.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"45 1","pages":"615 - 644"},"PeriodicalIF":1.6,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45353937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-06-19DOI: 10.1080/01490419.2022.2091695
Ruichen Zhang, Guojun Zhai, S. Bian, Houpu Li, B. Ji
{"title":"Analytical Method for High-Precision Seabed Surface Modelling Combining B-Spline Functions and Fourier Series","authors":"Ruichen Zhang, Guojun Zhai, S. Bian, Houpu Li, B. Ji","doi":"10.1080/01490419.2022.2091695","DOIUrl":"https://doi.org/10.1080/01490419.2022.2091695","url":null,"abstract":"Abstract High-accuracy seabed surface modelling provides multi-source high-precision fundamental geographic datasets for marine visual computing, seabed topography detection, marine biology, marine engineering and other fields. Proposed in this paper is a high-precision seabed surface model, which combines B-spline functions and Fourier-series, referred to as the Spline-Fourier-series (S-FS) method. Firstly, the mathematical relationship between the B-spline functions and Fourier-series in the modelling process is explored in depth, deducing the non-recursive basis functions of the Spline-Fourier-series model and the specific representation of the two dimensional Spline-Fourier-series model. Furthermore, using a publicly available Large-area bathymetric dataset, extensive experiments are conducted for comparisons with traditional methods (nearest-neighbor, bilinear, bicubic) and traditional Fourier-series, which generally shows the S-FS method has higher accuracy, better convergence and stronger robustness. Finally, based on its mathematically theoretical model, three characteristics (dimensionality reduction, multi-resolution expression and multi-scale visualization) of the S-FS method for constructing high-precision seabed surface are analyzed visually and deeply. Compared with B-spline function, the basic functions of the S-FS method inherit its prioritized compactly-supported performance and do not need to be recursively calculated anymore, thereby further showing its feasibility and extensibility in the field of high-precision seabed surface modelling.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"45 1","pages":"519 - 556"},"PeriodicalIF":1.6,"publicationDate":"2022-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46376325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-06-02DOI: 10.1080/01490419.2022.2082603
Rohini Selvaraj, Sannasiraj S. A., Sundar Vallam
{"title":"Hydrodynamic Modelling of Storm Surge with Modified Wind Fields along the East Coast of India","authors":"Rohini Selvaraj, Sannasiraj S. A., Sundar Vallam","doi":"10.1080/01490419.2022.2082603","DOIUrl":"https://doi.org/10.1080/01490419.2022.2082603","url":null,"abstract":"<p><b>Abstract</b></p><p>Propagation of tropical cyclones and their landfall along the coast affect the livelihood of the coastal community with loss of life, and Bay of Bengal is particularly vulnerable as past disasters have shown. The present study investigates the effects of tropical cyclones namely Phailin, Hudhud and Vardah during its landfall along the East Coast of India. Numerical modelling of storm surges primarily depends on the wind characteristics, for which, the performance of the simulated storm surge from cyclone wind and pressure fields of ECMWF is examined with Telemac-2D. The quality of the wind field is enhanced by applying available wind modification techniques, such as the parametric cyclone wind model superposed with ECMWF wind field, and the direct modification of ECMWF wind field. The superposed wind speed is found in good agreement with the measured wind data. The hydrodynamic simulation was then performed for the cyclonic events for the computation of the storm surge. The predictions agree well with the observed surges for the simulations performed with modified wind fields. The error reduced from 15 cm to 6 cm and model skill improved by 3% leading to a correlation coefficient of 0.98.</p>","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"107 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138516826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-05-18DOI: 10.1080/01490419.2022.2079778
Jianhu Zhao, Wenbiao Liang, Jinye Ma, Meiqin Liu, Yuqing Li
{"title":"A Self-Constraint Underwater Positioning Method without the Assistance of Measured Sound Velocity Profile","authors":"Jianhu Zhao, Wenbiao Liang, Jinye Ma, Meiqin Liu, Yuqing Li","doi":"10.1080/01490419.2022.2079778","DOIUrl":"https://doi.org/10.1080/01490419.2022.2079778","url":null,"abstract":"Abstract Aiming at the problem that lack of the measured sound velocity profile (SVP) leads to the unreliable underwater positioning solution, this paper proposed an efficient underwater positioning method by the self-constraint conditions of water depth and sound velocity gradient. To construct the depth constraint condition, the sound propagation distance error model is deduced by acoustic ray tracing, and the sound vertical propagation error model related to the incident angle and sound velocity error is given firstly. By fitting the vertical propagation error model, the reference depth is solved, and the vertical propagation distances between the transducer and the underwater control points of all observation epochs are gotten. Then with the solved vertical distance of each epoch and the sound velocity gradient from neighbor SVPs as the constraint conditions, the SVP is retrieved by the simulated annealing (SA) algorithm. With the retrieved SVP, the underwater positioning can be performed when the measured SVP is absent. The proposed method was verified by an experiment in the 3000 m depth water area of the South China Sea. The results achieved 2.07 m/s of standard deviation of the SVP inversion, centimeter-level horizontal positioning accuracy and 0.54 m of vertical positioning accuracy under the circumstance of lack of SVP measurement.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"46 1","pages":"62 - 82"},"PeriodicalIF":1.6,"publicationDate":"2022-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48982416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-05-09DOI: 10.1080/01490419.2022.2075499
Willian Ney Cassol, S. Daniel, É. Guilbert, N. Debese
{"title":"An Empirical Study of the Influence of Seafloor Morphology on the Uncertainty of Bathymetric Data","authors":"Willian Ney Cassol, S. Daniel, É. Guilbert, N. Debese","doi":"10.1080/01490419.2022.2075499","DOIUrl":"https://doi.org/10.1080/01490419.2022.2075499","url":null,"abstract":"Abstract The estimation of the uncertainty related to bathymetric data is essential in determining the quality of the data acquisition. This estimation is based on the covariance propagation considering the classical sounding georeferencing model. The estimation of the uncertainty using the Total Propagated Uncertainty (TPU) model is well described in the literature. Developing on this model, this study introduces an analysis of the morphological influence of the seafloor on the uncertainty value of the sounded points. Advancing the comprehension of the influence of the seafloor on the uncertainty value of the bathymetric data would improve the processing and interpretation of the seafloor surface as well as the structures present on the seafloor.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"45 1","pages":"496 - 518"},"PeriodicalIF":1.6,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44806664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-04-11DOI: 10.1080/01490419.2022.2064572
Tyler Susa
{"title":"Satellite Derived Bathymetry with Sentinel-2 Imagery: Comparing Traditional Techniques with Advanced Methods and Machine Learning Ensemble Models","authors":"Tyler Susa","doi":"10.1080/01490419.2022.2064572","DOIUrl":"https://doi.org/10.1080/01490419.2022.2064572","url":null,"abstract":"Abstract Accurate charting of nearshore bathymetry is critical to the safe and dependable use of coastal waterways frequented by the trading, fishing, tourism, and ocean energy industries. The accessibility of satellite imagery and the availability of various satellite-derived bathymetry (SDB) techniques have provided a cost-effective alternative to traditional in-situ bathymetric surveys. Furthermore, improved algorithms and the advancement of machine learning models have provided opportunity for higher quality bathymetric derivations. However, to date the relative accuracy and performance between traditional physics-based techniques, improved physics-based methods, and machine learning ensemble models have not been adequately quantified. In this study, nearshore bathymetry is derived from Sentinel-2 satellite imagery near La Parguera, Puerto Rico utilizing a traditional band-ratio algorithm, a band-ratio switching method, a random forest machine learning model, and the XGBoost machine learning model. The machine learning models returned comparable results and were markedly more accurate relative to other techniques; however, both machine learning models required an extensive training dataset. All models were constrained by environmental influences and image spatial resolution, which were assessed to be the limiting factors for routine use of satellite-derived bathymetry as a reliable method for hydrographic surveying.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"45 1","pages":"435 - 461"},"PeriodicalIF":1.6,"publicationDate":"2022-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48388000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-03-31eCollection Date: 2022-01-01DOI: 10.3389/fopht.2022.850394
Owuraku Titi-Lartey, Imran Mohammed, Winfried M Amoaku
{"title":"Toll-Like Receptor Signalling Pathways and the Pathogenesis of Retinal Diseases.","authors":"Owuraku Titi-Lartey, Imran Mohammed, Winfried M Amoaku","doi":"10.3389/fopht.2022.850394","DOIUrl":"10.3389/fopht.2022.850394","url":null,"abstract":"<p><p>There is growing evidence that the pathogenesis of retinal diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD) have a significant chronic inflammatory component. A vital part of the inflammatory cascade is through the activation of pattern recognition receptors (PRR) such as toll-like receptors (TLR). Here, we reviewed the past and current literature to ascertain the cumulative knowledge regarding the effect of TLRs on the development and progression of retinal diseases. There is burgeoning research demonstrating the relationship between TLRs and risk of developing retinal diseases, utilising a range of relevant disease models and a few large clinical investigations. The literature confirms that TLRs are involved in the development and progression of retinal diseases such as DR, AMD, and ischaemic retinopathy. Genetic polymorphisms in TLRs appear to contribute to the risk of developing AMD and DR. However, there are some inconsistencies in the published reports which require further elucidation. The evidence regarding TLR associations in retinal dystrophies including retinitis pigmentosa is limited. Based on the current evidence relating to the role of TLRs, combining anti-VEGF therapies with TLR inhibition may provide a longer-lasting treatment in some retinal vascular diseases.</p>","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"25 1","pages":"850394"},"PeriodicalIF":0.0,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11182157/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81223502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-03-29DOI: 10.1080/01490419.2022.2059601
Zhenqiang Du, Hongzhou Chai, Zeyu Li, Minzhi Xiang, Fan Zhang, Jun Hui
{"title":"Acoustic Ray-Trace Correction for UUVs Cooperative Localization in Deep Ocean Applications","authors":"Zhenqiang Du, Hongzhou Chai, Zeyu Li, Minzhi Xiang, Fan Zhang, Jun Hui","doi":"10.1080/01490419.2022.2059601","DOIUrl":"https://doi.org/10.1080/01490419.2022.2059601","url":null,"abstract":"Abstract Precise position of Unmanned Underwater Vehicles (UUVs) plays a decisive role in optimal formation control, reasonable path planning, and efficient cooperative operation. However, the traditional method has the deficiency of low ranging accuracy and contains systematic deviation in the deep ocean applications, which seriously affects the accuracy of UUVs position and makes the goal of UUVs optimal configuration no longer applicable. A novel acoustic ray-trace correction method is proposed for UUVs cooperative localization in deep ocean applications. Considering the bending of underwater sound ray and the variation of sound velocity, the model of UUVs cooperative localization based on ray-trace correction is established. Two master UUVs in shallow ocean and one slave UUV in deep ocean under five configurations are simulated. The experimental results show that the average position bias of UUVs cooperative localization under the five configurations are reduced by 57.97%, 62.29%, 68.51%, 74.93% and 82.54%, respectively, which can expand the application scenarios of UUV. Furthermore, the proposed method can overcome the drawback of systematic deviation in the traditional method, so as to be consistent with the goal of UUVs optimal configuration.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"45 1","pages":"595 - 614"},"PeriodicalIF":1.6,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46372703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-03-28DOI: 10.1080/01490419.2022.2057628
Xiao Yin, Hongzhou Chai, W. Xu, Liang Zhao, Huawei Zhu
{"title":"Realization and Evaluation of Real-Time Uncombined GPS/Galileo/BDS PPP-RTK in the Offshore Area of China’s Bohai Sea","authors":"Xiao Yin, Hongzhou Chai, W. Xu, Liang Zhao, Huawei Zhu","doi":"10.1080/01490419.2022.2057628","DOIUrl":"https://doi.org/10.1080/01490419.2022.2057628","url":null,"abstract":"Abstract The real-time kinematic (RTK) technology has been widely used as the high-precision positioning method in the offshore area. However, RTK requires a bi-directional communication and groups measurement errors together, thereby limiting its mass-market applications. Combining the advantages of precise point positioning (PPP) and RTK, PPP-RTK has become one of the hotspot technologies in the mass market. In this contribution, we propose the uncombined multi-GNSS PPP-RTK model using uncalibrated phase delays (UPDs) estimated from the legacy ionosphere-free and Melbourne-Wübbena combination. With the UPDs estimated based on 14 regional stations, we conduct PPP ambiguity resolution (AR) at 3 augmentation stations and derive precise atmospheric corrections, i.e., RMS of zenith tropospheric and slant ionospheric correction can be up to 4.89 mm and 2.20 cm, respectively. After applying atmospheric correction, the correct fixed solution of four on-board kinematic experiments can be better than 95% and the positioning accuracy can be better than 5 cm in both horizontal and vertical direction, showing the encouraging performance similar to RTK in the offshore area.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"45 1","pages":"577 - 594"},"PeriodicalIF":1.6,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43174760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marine GeodesyPub Date : 2022-03-22DOI: 10.1080/01490419.2022.2051648
Qizhi Zhuang, Jian Zhang, Liang Cheng, Hui Chen, Yanruo Song, Song Chen, Sensen Chu, Shengkun Dongye, Manchun Li
{"title":"Framework for Automatic Coral Reef Extraction Using Sentinel-2 Image Time Series","authors":"Qizhi Zhuang, Jian Zhang, Liang Cheng, Hui Chen, Yanruo Song, Song Chen, Sensen Chu, Shengkun Dongye, Manchun Li","doi":"10.1080/01490419.2022.2051648","DOIUrl":"https://doi.org/10.1080/01490419.2022.2051648","url":null,"abstract":"Abstract Using supervised and unsupervised classification on a single image to extract coral reef extent results in missing data and wrong extraction results. To improve the accuracy of coral reef extraction, this study proposes a novel technical framework for automatic coral reef extraction based on an image filtering strategy and spatiotemporal similarity measurements of pixel-level Sentinel-2 image time series. This method was applied to the Anda Reef, Daxian Reef, and Nanhua Reef, China, using 1464 Sentinel-2 images obtained from 2015–2020. Sentinel-2 images were automatically selected considering space, time, cloud cover, and image entropy after atmospheric correction. With the binary classification measurement standard using the digitization coral reef results of the Sentinel-2 images as the true value, the time series established by the modified normalized difference water index demonstrated high robustness and accuracy. Analyzing the time series curves of the coral reef and deep water verified that the spatiotemporal similarity measurement of this framework can stably extract the boundaries of the coral reef.","PeriodicalId":49884,"journal":{"name":"Marine Geodesy","volume":"45 1","pages":"195 - 231"},"PeriodicalIF":1.6,"publicationDate":"2022-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45195113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}