scholarly journals Analisis Nilai Hambur Balik pada Kapal Karam (Wreck) Menggunakan Data Multibeam Echosounder di Perairan Belawan

2018 ◽  
Vol 4 (1) ◽  
pp. 51-67
Author(s):  
Brama Setya Indramawan ◽  
Anang Prasetia Adi ◽  
Eka Djunarsjah ◽  
Wahyu W. Pandoe
Keyword(s):  
Response Analysis ◽  
Analysis Tool ◽  
Side Scan Sonar ◽  
Multibeam Echosounder ◽  
Sediment Analysis ◽  
Angular Response

Wreck (kapal karam) sangat membahayakan bagi pelayaran terutama di alur pelayaran, maka menjadi penting untuk dapat mengetahui posisi, dimensi dan karaktersik wreck tersebut. Pendeteksian wreck selama ini menggunakan magnetometer dan side scan sonar, padahal dengan kemampuan Multibeam Echosounder (MBES) saat ini pendeteksian itu dapat dilakukan oleh MBES, karena mampu menghasilkan data batimetri dan data hambur balik dari material dasar laut. Penelitian ini memanfaatkan data batimetri MBES untuk mendapatkan nilai kedalaman dan nilai intensitas dari wreck. Dari nilai intensitas inilah dapat diketahui material badan kapal yang tenggelam. Data yang digunakan adalah data MBES Kongsberg EM2040C hasil Survei Pushidrosal tahun 2016 di perairan Belawan. Pengolahan data menggunakan software Caris Hips and Ships 9.0 dengan cara membuat CUBE Surface untuk mendapatkan nilai kedalaman dan estimasi dimensi (panjang dan lebar) dari wreck. Untuk mendapatkan nilai hambur balik menggunakan metode Angular Response Analysis (ARA) dan Sediment Analysis Tool (SAT). Hasil penelitian ini diperoleh nilai intensitas dari kapal karam berkisar -9,7 sampai -3,02 dB pada wreck bermaterial besi dan -27,3 sampai -21,5 pada wreck bermaterial kayu dengan nilai koefisien refleksi 0.928 dan 0.414

scholarly journals PENGUKURAN DAN ANALISIS HAMBUR BALIK AKUSTIK MENGGUNAKAN TEKNOLOGI MULTIBEAM ECHOSOUNDERUNTUK KLASIFIKASI SEDIMEN DASAR LAUT TELUK PALU

2020 ◽  
Vol 12 (2) ◽  
pp. 439-455
Author(s):  
Rizqi Ayu Farihah ◽  
Henry Munandar Manik ◽  
Gentio Harsono
Keyword(s):  
Support Vector Machine ◽  
Silty Sand ◽  
Support Vector ◽  
Response Analysis ◽  
Multibeam Echosounder ◽  
Angular Response

Nilai Hambur balik dapat menggambarkan kondisi sedimen di dasar perairan, termasuk ukuran butir dari sedimen dasar perairan. Tujuan penelitian ini untuk mendeteksi, mengklasifikasi dan memprediksi tipe dasar perairan berdasarkan nilai hambur balik menggunakan Angular Response Analysis (ARA) dan Support Vector Machine (SVM) sehingga didapatkan peta spasial sebaran sedimen di Teluk Palu. Data batimetri dan intensitas hambur balik diambil pada 5-9 Oktober 2018 menggunakan multibeam echosounder Kongsberg EM 302 dengan frekuensi 30 kHz dan 10 sampel sedimen tahun 2012 milik PUSHIDROSAL. Hasil penelitian menunjukkan sebaran sedimen dasar Teluk Palu dengan metode ARA didominasi oleh pasir (sand) dan lanau (silt) sedangkan dengan metode SVM didominasi oleh pasir berlanau (silty sand), lanau (silt) dan pasir (sand). Hasil uji akurasi untuk metode ARA sebesar 50% sedangkan hasil uji akurasi untuk metode SVM menghasilkan overall accuracy dengan nilai 60%. Prediksi tipe dasar perairan di Teluk Palu yang paling mendekati keadaan sebenarnya adalah hasil prediksi dengan metode SVM yaitu pasir berlanau, lanau dan pasir.

scholarly journals INTEGRASI DATA MULTIBEAM BATIMETRI DAN MOSAIK BACKSCATTER UNTUK KLASIFIKASI TIPE SEDIMEN

2017 ◽  
Vol 7 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Anang Prasetia Adi ◽  
Henry M Manik ◽  
Sri Pujiyati
Keyword(s):  
Multibeam Echosounder ◽  
Sediment Analysis ◽  
Angular Response ◽  
Combined Uncertainty

Sistem multibeam echosounder tidak hanya memperoleh presisi tinggi dalam pengolahan data batimetri saja, tetapi juga mendapatkan resolusi tinggi dalam data backscatter strenght (BS) dasar perairan. Sejumlah penelitian telah menerapkan metode akustik untuk mengklasifikasikan tipe sedimen dasar perairan dengan menggunakan data backscatter, dan hasil klasifikasi yang diperoleh lebih baik daripada sampling sedimen secara tradisional. Tujuan penelitian ini untuk mengintegrasikan hasil data multibeam echosounder dalam penentuan batimetri dan pengklasifikasian tipe sedimen dasar perairan.Penelitian menggunakan data survei batimetri multibeam echosounder Kongsbergs EM 2040C di Sungai Kapuas Pontianak, Kalimantan Barat. Penentuan batimetri menggunakan metode Combined Uncertainty and Bathymetry Estimator (CUBE), sedangkan klasifikasi tipe sedimen menggunakan metode Angular Response (ARA) dan Sediment Analysis (SAT) yang semuanya tertanam dalam software Caris Hips and Ships versi 9.0. Hasil klasifikasi tipe sedimen secara unsupervised terdapat empat tipe sedimen. Nilai intensitas tipe sedimen kerikil (gravel) berkisar antara -16 dB hingga -13 dB, pasir (sand) berkisar antara -22 dB hingga -17 dB, lumpur (silt) antara -26 dB hingga -23 dB dan lempung (clay) berkisar antara -34 dB hingga -29 dB.

scholarly journals The Hyper-Angular Cube Concept for Improving the Spatial and Acoustic Resolution of MBES Backscatter Angular Response Analysis

Geosciences ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 446 ◽  
Author(s):  
Evangelos Alevizos ◽  
Jens Greinert
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Data Structure ◽  
Supervised Classification ◽  
Incidence Angle ◽  
Ground Truth ◽  
Response Analysis ◽  
Ground Truth Data ◽  
Angular Response ◽  
Artificial Neural

This study presents a novel approach, based on high-dimensionality hydro-acoustic data, for improving the performance of angular response analysis (ARA) on multibeam backscatter data in terms of acoustic class separation and spatial resolution. This approach is based on the hyper-angular cube (HAC) data structure which offers the possibility to extract one angular response from each cell of the cube. The HAC consists of a finite number of backscatter layers, each representing backscatter values corresponding to single-incidence angle ensonifications. The construction of the HAC layers can be achieved either by interpolating dense soundings from highly overlapping multibeam echo-sounder (MBES) surveys (interpolated HAC, iHAC) or by producing several backscatter mosaics, each being normalized at a different incidence angle (synthetic HAC, sHAC). The latter approach can be applied to multibeam data with standard overlap, thus minimizing the cost for data acquisition. The sHAC is as efficient as the iHAC produced by actual soundings, providing distinct angular responses for each seafloor type. The HAC data structure increases acoustic class separability between different acoustic features. Moreover, the results of angular response analysis are applied on a fine spatial scale (cell dimensions) offering more detailed acoustic maps of the seafloor. Considering that angular information is expressed through high-dimensional backscatter layers, we further applied three machine learning algorithms (random forest, support vector machine, and artificial neural network) and one pattern recognition method (sum of absolute differences) for supervised classification of the HAC, using a limited amount of ground truth data (one sample per seafloor type). Results from supervised classification were compared with results from an unsupervised method for inter-comparison of the supervised algorithms. It was found that all algorithms (regarding both the iHAC and the sHAC) produced very similar results with good agreement (>0.5 kappa) with the unsupervised classification. Only the artificial neural network required the total amount of ground truth data for producing comparable results with the remaining algorithms.

Seismic design spectra for different soil classes

2013 ◽  
Vol 46 (2) ◽  
pp. 79-87 ◽  
Author(s):  
Rajesh P. Dhakal ◽  
Sheng-Lin Lin ◽  
Alexander K. Loye ◽  
Scott J. Evans
Keyword(s):  
Seismic Design ◽  
Soft Soil ◽  
Response Analysis ◽  
Seismic Demand ◽  
Analysis Tool ◽  
Spectral Acceleration ◽  
Acceleration Response ◽  
Design Spectra ◽  
Nonlinear Site Response ◽  
Short Period

This paper investigates the validity of the soil class dependent spectral shape factors used to calculate seismic design actions in the New Zealand seismic design standard NZS1170.5, which currently specifies seismic design spectra corresponding to five different soil classes. According to the current provisions stipulated in NZS1170.5, for all natural periods, the seismic demand for structures on soft soil is either equal to or greater than that for structures on hard soil. This is opposite to the basic structural dynamics theory which suggests that an increase in stiffness of a system results in an increase in the acceleration response. In this pretext, a numerical parametric study is undertaken using a nonlinear site response analysis tool in order to capture the effect of soil characteristics on structural seismic demand and to scrutinize the validity of the current site specific seismic design spectra. It is identified that the level of input ground motion intensity and shear stiffness of the soil deposit (represented by its shear wave velocity Vs) greatly affect the maximum acceleration and frequency content of the surface motion. The study found some shortfalls in the way the current code defines seismic design demand, in particular the hierarchy of soil stiffness at low structural periods. It was found that stiff soils generally tend to have a higher spectral acceleration response in comparison to soft soils although this trend is less prominent for high intensity bed rock motions. It was also found that for medium to hard soils the spectral acceleration response at short period is grossly underestimated by the current NZS1170.5 provisions. Based on the outcomes of the parametric numerical analyses, a revised strategy to determine structural seismic demand for different soil classes is proposed and its application is demonstrated through an example.

Application of Wavelets in Detection of Cavities Under Pavements by Surface Waves

2003 ◽  
Vol 1860 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Parisa Shokouhi ◽  
Nenad Gucunski ◽  
Ali Maher
Keyword(s):  
Wavelet Transform ◽  
Wavelet Transforms ◽  
Element Model ◽  
Energy Concentration ◽  
Response Analysis ◽  
Analysis Tool ◽  
Cavity Detection ◽  
Time Frequency ◽  
Homogeneous Half Space ◽  
Power Spectral

Application of wavelet transforms in the detection of underground shallow cavities is investigated. Wave propagation is simulated through a transient response analysis on an axisymmetric finite element model. Cavities in a homogeneous half-space and a pavement system of a variety of shapes and embedment depths are considered. The continuous wavelet transform is introduced as a new tool for cavity detection. Effects of different types of cavities on power spectral surfaces (power spectral amplitudes versus frequency and receiver location) and Gaussian wavelet time-frequency maps (wavelet transform coefficients versus time and frequency) are studied. Results show strong energy concentration in power spectral surfaces right in front of a cavity in certain frequency bands. Time and frequency signatures of waves reflected from near and far faces of the cavity can be clearly observed in the wavelet time-frequency maps. These observations are used to locate and estimate the size of the cavity. It is demonstrated that the wavelet transform is a promising analysis tool for cavity detection and characterization.

Multiswath multibeam echosounder for efficient seabed backscatter imaging and classification

2020 ◽  
Author(s):  
Didier Charlot ◽  
Philippe Alain ◽  
Geraldine Duffait ◽  
Olivier Lerda ◽  
Guillaume Matte
Keyword(s):  
Grazing Angle ◽  
Sidescan Sonar ◽  
Sediment Type ◽  
Ecosystem Research ◽  
Multibeam Echosounder ◽  
Single Beam ◽  
Angular Response ◽  
Seabed Classification ◽  
Sonar System ◽  
Echo Sounder

<p><strong>MULTISWATH MULTIBEAM ECHOSOUNDER FOR EFFICIENT SEABED BACKSCATTER IMAGING AND CLASSIFICATION</strong></p><ol><li><strong> Didier Charlot<sup>(1)</sup>,Philippe  Alain<sup>(1)</sup>, Géraldine Duffait<sup>(2)</sup> ,Olivier Lerda<sup>(2)</sup>, Guillaume Matte<sup>(2)</sup></strong></li> </ol><p> (1) iXBlue Sonar System Division, 256 rue Rivoalon, 29200 Brest,  France</p><p>(2) iXBlue Sonar System Division, 46 Quai F. Mitterrand, 13600 La Ciotat, France.</p><p> </p><p>               Managing marine resources and habitats require a classification system to identify and characterized seabed properties. Acoustic systems are recognized to be remote sensing tools that measure efficiently sediment properties and seabed morphology [1].Single beam, multibeam echosounder and sidescan sonar systems are commonly used to characterize seabed type by respectively analyzing echo strength returns, backscatter (BS) angular response, and texture analysis. Multibeam  (and interferometric sidescan ) systems  have the great advantage to measure the bottom bathymetry hence the true grazing angle at least in the across track direction. But there are still some challenges to face to get a robust calibrated BS value. </p><p>First, standard multibeam systems  do not measure directly the full BS backscatter angular response on each soundings. This can be accomplished by using a dual axis multibeam to record the BS in the along track direction[2]. The BS angular response is  a powerful metric to characterize the sediment type. </p><p>Second, the BS response is sensitive to the insonification direction (azimuth) and this dependency should also be considered to improve calibration procedure.  Recently, a full 3D steerable high resolution multibeam system has been developed [3]. First investigation ([3],[4]) have shown the high potential of multiswath multibeam system. With the 3D steerable swath capability, the bidirectional BS angular response can be recorded on each insonified soundings. This presentation will emphasize recent advances in processing using the  full multiswath multibeam capabilities.</p><p> </p><p>References:</p><p>[1] John T. Anderson, Editor,”Acoustic Seabed Classification of Marine Physical And biological Landscapes”, ICES Report N° 286, August 2007</p><p>[2]M.  Gutberlet and H. W. Schenke ,“HYDROSWEEP : New Era in High precision bathymetric Surveying in Deep and Shallow water” , Marine Geodesy,1989, Vol13,pp1-23</p><p>[3] F. Mosca & al., “Scientific potential of a new 3D multibeam echosounder in fisheries and ecosystem research”, Fisheries Research 178 pg. 130-141, 2016.</p><p>[4] Nguyen, Trung Kiên , Charlot D. , Boucher  J.-M , Le Chenadec G.,  Fablet R., “Seabed classification using a steerable multibeam echo sounder”. Oceans 2016 MTS/IEEE 2016,Monterey</p><p>[5] Nguyen, Trung Kiên, ”Seafloor classification with a multi-swath multi-beam echo sounder”, PhD thesis 2017, IMT Atlantique; http://www.theses.fr/2017IMTA0035</p>

An Improved Fault-to-Site Analysis Tool Towards Fully HPC-Enhanced Physics-Based Urban Area Response Estimation

2016 ◽  
Vol 10 (05) ◽  
pp. 1640018 ◽  
Author(s):  
Pher Errol B. Quinay ◽  
Tsuyoshi Ichimura
Keyword(s):  
Urban Area ◽  
Ground Motions ◽  
Earthquake Response ◽  
Response Analysis ◽  
Analysis Tool ◽  
Good Balance ◽  
Site Analysis ◽  
Step Procedure ◽  
Earthquake Response Analysis ◽  
Area Response

This paper describes the improvement to a fault-to-site analysis tool for use in a fully HPC-enhanced physics-based urban earthquake response analysis. We developed a three-step procedure, involving coarse and refined partitioning for the preprocessing stage, that achieves good balance in computational load and FE nodes used in communications. An end-to-end approach to computing in K computer was also implemented. The results of strong- and weak-scaling tests validate the capability of the tool for application to dynamic analysis involving billions of unknowns. In application to reproduction of observed ground motions, improvements in solution in comparison with previously conducted validations were obtained. The tool was also used to generate synthetic ground motions for analyzing the response of thousands of buildings in an urban area due to a scenario earthquake.

scholarly journals Identifikasi Hazard dari Hasil Data Free Span pada Jalur Pipa Bawah Laut Lapangan Bekapai Menggunakan Data Multibeam Echosounder dan Side Scan Sonar

2019 ◽  
Vol 2018 (1) ◽  
Author(s):  
Muhammad Biana Ravenska ◽  
Ni Made Rai Ratih Cahya Perbani
Keyword(s):  
Coming Out ◽  
Research Area ◽  
Hazard Identification ◽  
Oil Fields ◽  
Side Scan Sonar ◽  
Multibeam Echosounder ◽  
Operation Process ◽  
Oil And Natural Gas ◽  
Safe Condition ◽  
Subsea Pipelines

ABSTRAKLapangan Bekapai merupakan salah satu lapangan minyak yang memproduksi dan mendistribusikan minyak dan gas alam lewat pipa bawah laut. Untuk itu perlu dilakukan inspeksi secara berkala untuk meminimalkan terjadinya hazard baik yang berasal dari proses instalasi maupun dari proses operasi, di antaranya berupa free span. Penelitian ini menggunakan data multibeam echosounder (MBES) untuk mendapatkan data panjang dan posisi free span, sedangkan data side scan sonar (SSS) untuk interpretasi objek pipa dan perkiraan tinggi free span. Profil yang dibangun dari data MBES digunakan untuk memastikan adanya cekungan pada lokasi free span yang terdeteksi. Kriteria identifikasi hazard berupa free span pada jalur pipa bawah laut menggunakan DNV RP F-105 dengan panjang dan tinggi maksimum yang diperbolehkan adalah 14 meter dan 0,6 meter. Free span maksimum yang terdeteksi di lokasi penelitian memiliki panjang 9,2 meter dan tinggi 0,24 meter, yang masih dikategorikan aman atau tidak terjadi hazard pada pipa bawah laut di lokasi penelitian.Kata kunci: free span, multibeam echosounder, side scan sonar ABSTRACTBekapai Field has been known as one of the oil fields which produce and transport oil and natural gas through the subsea pipelines. It becomes so important to inspect periodically for minimizing the coming out of hazards, either during installation or operation process. One of the hazards is a free span. This research uses multibeam echosounder (MBES) data to specify the length and the position of free span, while side scan sonar (SSS) data is used to interpret the object of pipeline and to estimate the height of free span. Profiles that are builded from MBES data are used to ascertain the existence of a basin under the detected free span. DNV RP F-105 as the criteria of hazard identification for free span requires the maximum of length and height be allowed are 14 meters and 0.16 meters. The maximum free span detected at the research area has 9.2 meters length and 0.24 meters height, thus it can be stated as a safe condition category or there is no subsea pipelines hazards at the research area.Keywords: free span, multibeam echosounder, side scan sonar

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