Browsing by Author "Fernandes, W.A."
Now showing items 1-20 of 28
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A brief report on mets system
Fernandes, W.A. (National Institute of Oceanography, 2005)Mets system is basically a gas monitoring system, used for the detection of underwater gas. The system consists of a sensor, datalogger and energy module. The sensor works on the diffusion techniques. The system can be ... -
A method to eliminate refraction artifacts in EM1002 multibeam echosounder system (Swath bathymetry and seabed surveys of EEZ)
Fernandes, W.A. (National Institute of Oceanography (CSIR); Dona Paula, Goa; India., 2011)The multi-beam echo-sounder systems acquire bathymetry data with additional information. This supplementary data along with proper bathymetry can be further used in scientific studies. As observed most of the multi-beam ... -
An approach towards solving refraction problems in EM1002 multi-beam echo-sounder system
Fernandes, W.A. (National Institute of Oceanography, India, 2007)Multi-beam echo-sounding is the technique in which multiple beams of acoustic in nature are sent down to seabed and upon reflection, they are received back and processed to give depths values. The report is focused to give ... -
An experiment towards characterizing seahorse sound in a laboratory controlled environment
Saran, A.K.; Sreepada, R.A.; Chakraborty, B.; Fernandes, W.A.; Srivastava, R.; Kuncolienker, D.S.; Gawde, G. (Department of Electronics and Telecommunication-Goa College of Engineering, 2011)There are many reports of sounds produced by Seahorse (Hippocampus), however, little is known about the mechanism of sound production. Here, we investigate sound produced by the seahorse during feeding. We attempt to try ... -
An insight into the 'Fifty-Fathom-Flat' off India's west coast
Mukhopadhyay, R.; Fernandes, W.A.; Naik, Y.S.; Karisiddaiah, S.M. (Elsevier, 2010)The architecture of the western continental margin of India (WCMI) is likely to have been influenced in the geological past by several episodes of volcanic eruptions, rifting, and continental break-up. The WCMI is characterized ... -
Application of hybrid techniques (self-organizing map and fuzzy algorithm) using backscatter data for segmentation and fine-scale roughness characterization of seepage-related seafloor along the western continental margin of India
Chakraborty, B.; Menezes, A.A.A.; Dandapath, S.; Fernandes, W.A.; Karisiddaiah, S.M.; Haris, K.; Gokul, G.S. (IEEE, 2015)In this paper, a seafloor characterization technique to unravel the number of data classes using multibeam echo-sounding backscatter data has been demonstrated. An application of self-organizing maps (SOMs) to backscatter ... -
Bathymetric techniques and Indian Ocean applications
Chakraborty, B.; Fernandes, W.A. (InTech, 2012)The acoustic echosounders are the traditional workhorse of bathymetry measurements. The article highlights the differences between single beam and multibeam echosounders, besides indicating how complimentary they are to ... -
Characterization of seafloor pockmark seepage of hydrocarbons employing fractal: A case study from the western continental margin of India
Dandapath, S.; Chakraborty, B.; Maslov, N.; Karisiddaiah, S.M.; Ghosh, D.; Fernandes, W.A.; Menezes, A.A.A. (Elsevier, 2012)A quantitative technique is applied to describe the seafloor seepages based on the multi-beam backscatter and bathymetric investigations to characterize the pockmark morphology. The variable seafloor backscatter strength ... -
Characterization of Yellow Seahorse Hippocampus kuda feeding click sound signals in a laboratory environment: an application of probability density function and power spectral density analyses
Chakraborty, B.; Saran, A.K.; Kuncolienker, D.S.; Sreepada, R.A.; Haris, K.; Fernandes, W.A. (Taylor and Francis, 2014)Do the sounds generated by different-sized fish of different sexes differ from each other in temporal, spectral or intensity patterns? Such differences would enable the development of passive acoustic techniques to locate ... -
Characterizing slope morphology using multifractal technique: a study from the western continental margin of India.
Chakraborty, B.; Karisiddaiah, S.M.; Menezes, A.A.A.; Haris, K.; Gokul, G.S.; Fernandes, W.A.; Kavitha, G. (Springer, 2014)Here, we present the slope configuration of the submarine gullies, ridges and the adjacent slump zone off Goa, along the western continental margin of India utilizing multibeam bathymetric and single-channel seismic data. ... -
Characterizing the estuarine riverbed using acoustic technique
Chakraborty, B.; Menezes, A.A.A.; Muthukumar, K.; Fernandes, W.A.; Saran, A.K.; Mehra, P. (IEEE, 2010)Single transact of multi-beam bathymetry and backscatter data is acquired from Mandovi estuary of Goa, India for three days during the pre-monsoon session. The measurements were made during the high tide. In this work, ... -
Characterizing three shallow-water locations off Goa, India, using passive acoustic data
Chanda, K.; Chakraborty, B.; Mahale, V.; Latha, G.; Fernandes, W.A. (Acoustical Society of America (ASA), 2020)In this study, an analysis of the passive acoustic data is carried out for the quantitative characterization of shallow-water acoustic environments from three major estuarine systems of Goa during the months of March and ... -
Development of multi-channel data logger for passive acoustic measurements
Fernandes, W.A.; Agarvadekar, Y.; Chakraborty, B. (Acoustical Society of India, 2018)Recording of passive acoustic data involves a listening device along with an instrumentation system. The passive listening device transforms mechanical disturbances to electrical signals. The subsequent sampling and logging ... -
Echo-waveform classification using model and model free techniques: Experimental study results from central western continental shelf of India
Chakraborty, B.; Navelkar, G.S.; Desai, R.G.P.; Janakiraman, G.; Mahale, V.; Fernandes, W.A.; Rao, N. (Marine Technology Society, 2005)Seafloor classifications and characterization using acoustic backscatter data from the central western continental shelf of India is presented in this work. Single beam sea-floor echo data using two frequencies: 33 kHz and ... -
Fine scale analyses of a coralline bank mapped using multi-beam backscatter data
Menezes, A.A.A.; Naik, M.; Fernandes, W.A.; Haris, K.; Chakraborty, B.; Estiberio, S.; Lohani, R.B. (NIOT, Chennai, 2015)In this work, we have developed a classification technique to characterize the seafloor of the Gaveshani (coralline) bank area using multi-beam backscatter data. Softcomputational techniques like the artificial neural ... -
Fish Sound Characterization Using Multifractal Detrended Fluctuation Analysis
Chanda, K.; Shet, S.; Chakraborty, B.; Saran, A.K.; Fernandes, W.A.; Latha, G. (World Scientific Pub Co Pte Lt, 2020)This work involves the application of a non-linear method, multifractal detrended fluctuation analysis (MFDFA), to describe fish sound data recorded from the open waters of two major estuarine systems. Applying MFDFA, the ... -
How biological (fish) noise affects the performance of shallow water passive array system
Fernandes, W.A.; Chakraborty, B.; Haris, K.; Vijayakumar, K.; Sundar, D.; Luis, R.A.A.; Mahanty, M.M.; Latha, G. (NIOT, Chennai, 2015)Passive acoustic data off Grand Island, Goa were acquired using a single wideband hydrophone system deployed at the water depth of ~20.5 m during the month of April, 2014. The 4- elements hydrophone array with an aperture ... -
Hydrographic features of the gas hydrate studies survey area of cruise AASGH2 in the Arabian Sea
Charyulu, R.J.K.; Fernandes, W.A.; Gawde, S.; Almeida, A.M. (National Institute of Oceanography, India, 2006)Hydrographic data were collected from the research ship ‘A.A. Siderenko’ in the Arabian Sea in [(70.55 degrees E, 70.95 degrees E) x (15.00 degrees N, 15.50 degrees N)] grid at 15 selected stations, in between stn. Nos ... -
Hydrographic features of the gas hydrate studies survey area of cruise AASGH4 in the Bay of Bengal
Charyulu, R.J.K.; Fernandes, W.A.; Gawde, S.; Almeida, A.M. (National Institute of Oceanography, India, 2006)Hydrographic data were collected from the research ship ‘A.A. Siderenko’ in the Bay of Bengal in [(81.70 degrees E, 82.90 degrees E) x (15.75 degrees N, 16.20 degrees N)] grid at 9 selected stations, in between stn. Nos ... -
Hydrography and water masses in the southeastern Arabian Sea during March-June 2003
Shenoi, S.S.C.; Shankar, D.; Michael, G.S.; Kurian, J.; Varma, K.K.; RameshKumar, M.R.; Almeida, A.M.; Unnikrishnan, A.S.; Fernandes, W.A.; Barreto, N; Gnanaseelan, C.; Mathew, R.; Praju, K.V.; Mahale, V. (Indian Academy of Sciences, 2005)This paper describes the hydrographic observations in the southeastern Arabian Sea (SEAS) during two cruises carried out in March–June 2003 as part of the Arabian Sea Monsoon Experiment. The surface hydrography during ...