Mjerenje profila brzine morskih struja akustičkom metodom

scientific master's theses

• Title (english): Measurement of the sea current velocity profiles by acoustic method
• Author: Dražan Skelin
• Mentor: Bojan Ivančević (mentor)
• Committee member: Bojan Ivančević (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Electroacoustics); Zagreb
• Defense date and country: 2011-12-01, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

Rad objašnjava potrebu za mjerenjem morskih struja, te prikazuje povijesni pregled i postojeće metode mjerenja. Objašnjeni su temeljni teorijski principi širenja zvuka u moru, te mjerenja profila brzine morskih struja akustičkom metodom, odnosno princip rada akustičkog mjerila profila brzine morskih struja (ADCP – Acoustic Doppler Current Profiler). Pobliže je objašnjen Dopplerov efekt i izračun radijalne brzine, odnosno trodimenzionalnog vektora brzine. Prikazani su osnovni principi uskopojasnih i širokopojasnih tehnika obrade reflektiranog signala. U posebnom poglavlju su opisane karakteristike HA pretvarača, te njihove međusobne konfiguracije pogodne za mjerenje morskih struja (prednosti i nedostaci konfiguracija sa tri ili četiri HA pretvarača). Također su prikazane praktične primjene akustičkog strujomjera, odnosno integracije sa drugim senzorima pri mjerenju morskih struja. Za potrebe rada provedeno je in situ mjerenje profila brzine morskih struja na dvije pozicije u Luci Kaprije s prostorno vertikalnom rezolucijom od 1 m i vremenskom rezolucijom od 10 minuta. Posebna pažnja je usmjerena na analizu i obradu mjernih podataka, odnosno načine prikaza obrađenih podataka (rezultata) mjerenja.

Abstract (english)

This thesis explains the need for sea current measurement and shows the history of the sea current measurements, as well as the present measurement methods. The basic theoretical principles of underwater sound propagation and measurement of the sea currents velocity profiles by the acoustic method are explained. Also the principle of operation of Acoustic Doppler Current Profiler (ADCP) is explained. The Doppler effect, radial velocity and three-dimensional vector are explained thoroughly. The basic principles of narrowband and broadband processing technices of Doppler shifted signal are explained. Charactheristics of the hydro-acoustic transducers and their configurations applicable for current measurement (advantages and disadvantages of three and four HA transducers) are explained in separate chapter. ADCP applications and integrations with other sensors are shown. For purpouse of this thesis in situ measurement of the sea current velocity profiles were conducted at the Luka Kaprije with vertical spatial resolution of 1 m and temporal resolution of 10 minutes. Special attention was given to data analysys and processing and presentation of measurement results.

• Keywords: ADCP; mjerenje profila brzine morskih struja; Dopplerov efekt; akustički strujomjer
• Keywords (english): ADCP; sea current velocity profile measurement; Doppler effect; acoustic sea current meter
• Language: croatian
• URN:NBN: urn:nbn:hr:168:345995
• Study programme: Title: Postgraduate master programme in electrical engineering; Study programme type: university; Study level: postgraduate; Academic / professional title: Magistar znanosti elektrotehnike (Magistar znanosti elektrotehnike)
• Catalog URL: http://lib.fer.hr/cgi-bin/koha/opac-detail.pl?biblionumber=37810
• Type of resource: Text
• Extent: 117 str. ; 30 cm
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-07-12 09:42:24