Objetivo
The main objective of this project is to investigate the interrelationship between acoustic reflections from the seabed measured with an Ultrasonic Signal Processor (USP). A successful conclusion to the project would have enabled compilation of a classification table of results determined from analysis of acoustic reflections. This would lead to engineering properties and stability of the sea floor to be directly inferred, such that more rapid and cheaper surveys of areas can be achieved using acoustic methods.
Could geophysical surveys, research vessels or even merchant shipping in the future routinely acquire continuous seabed identification from echo-sounders as a matter of course?
A tempting prospect surely, and one we believe we are close to achieving. From October 1986 to September 1988 a project titled "Classification of the Sea Floor Engineering Properties for Marine Foundation and Structure" has been funded under the THERMIE, Hydrocarbons Scheme (Phases 1-6).
The parallel receiver has been built and tested at sea under a wide variety of conditions and has proved to give a great improvement on the repeatability and reliability of E1 and E2 capture. There are a number of features which still need to be addressed in order to fully capitalise on the USP development.
1) Echo Sounder pulse width sensing circuitry should be designed and incorporated so that a suitable correction can be made.
2) An interference blanking circuit is needed for USP operation on seismic survey vessels.
3) With the present electronics it is necessary to "balance" the noise level present necessitating use of an oscilloscope. An automatic circuit would make the parallel receiver more attractive to a wider client base.
4) The error at the integrators due to noise from too large gating periods, slow PRF's or bad weather needs to be corrected/improved.
5) Bottom lock circuitry may be needed where fish and plankton layers cause problems (e.g. Mediterranean).
There is wihtout doubt a general consensus among USP users that the system provides real and tangible benefits during its use. However the package still suffers greatly from the lack of a key to the colours being used on the screen during software displays. This makes exchanged data sets difficult to comprehend without re-analysis of the tracks with your own preferred (and obviously well known) box file. The USP system is essentially of most use at present to those who can afford the time to thoroughly familiarise themselves with its operation over areas of known sea bed types, a process that could take several weeks. Only then when working on new and previously unsurveyed grounds will the colours on the screen represent a meaningful image, without recourse to costly and extensive ground truthing calibrations. The colours should of course be standardised but as yet this has not been achieved by the geophysical fraternity. The absence of a key to colour coding of the USP data may ultimately prove to be the limiting factor for its commercial success and is essential if the data is to be independently interpretable.
To determine the seabed type the USP electronic system extracts two parameters from the returning signals. The initial analysis (E1) is of the first echo return, consisting of reflections which return directly to the transducer from the seabed. Research on the first programme has shown this to primarily relate to bottom "roughness". The subsequent and most novel analysis (E2) is of the second echo return, a phenomena neglected in most acoustic theory as unimportant. This second analysis has been shown primarily to relate to bottom "hardness".
However USP technology currently requires ground truthing to calibrate its output which is variable dependent on such factors as:
- Signals receiving & processing circuits in first gain stages of echo-sounder electronics
- Echo-sounder frequency, pulse width, transducer type mounting on hull, etc.
- Vessel's hull shape (especially in shallow water).
- Background acoustic level (ship's engine, etc.)
- Water temperature and salinity.
Ideally, USP output should be capable of being supplied in a wholly standardised format to be deployed on 'Craft of Opportunity' with minimal, if any, calibration. The participating companies will further research and develop a system which will be both absolute in seabed classification and formatted for inclusion in automatic data acquisition systems. The major technological innovation will be design, building and testing of a parallel electronic receiver to optimise E1 and E2 capture (possibly also a third bottom characteristics index, E3).
The project will be accomplished over a 2 year period commencing 1st August 1989 in the following phases :
Phase 7: Further development of USP. Investigations of relative importance of error variables. Continued individual field testing of instrumentation, combined with ground truthing. Continued mathematical analysis and numerical modelling.
Phase 8: Major field trials to capture large data set. Continue modelling aspects.
Phase 9: Analysis of data set. Development of techniques to calibrate/compensate for variables encountered.
Conclude modelling aspects. Reporting.
Ámbito científico (EuroSciVoc)
CORDIS clasifica los proyectos con EuroSciVoc, una taxonomía plurilingüe de ámbitos científicos, mediante un proceso semiautomático basado en técnicas de procesamiento del lenguaje natural. Véas: El vocabulario científico europeo..
CORDIS clasifica los proyectos con EuroSciVoc, una taxonomía plurilingüe de ámbitos científicos, mediante un proceso semiautomático basado en técnicas de procesamiento del lenguaje natural. Véas: El vocabulario científico europeo..
Este proyecto aún no se ha clasificado con EuroSciVoc.
Sugiera los ámbitos científicos que considere más relevantes y ayúdenos a mejorar nuestro servicio de clasificación.
Para utilizar esta función, debe iniciar sesión o registrarse
Programa(s)
Programas de financiación plurianuales que definen las prioridades de la UE en materia de investigación e innovación.
Programas de financiación plurianuales que definen las prioridades de la UE en materia de investigación e innovación.
Tema(s)
Las convocatorias de propuestas se dividen en temas. Un tema define una materia o área específica para la que los solicitantes pueden presentar propuestas. La descripción de un tema comprende su alcance específico y la repercusión prevista del proyecto financiado.
Las convocatorias de propuestas se dividen en temas. Un tema define una materia o área específica para la que los solicitantes pueden presentar propuestas. La descripción de un tema comprende su alcance específico y la repercusión prevista del proyecto financiado.
Convocatoria de propuestas
Procedimiento para invitar a los solicitantes a presentar propuestas de proyectos con el objetivo de obtener financiación de la UE.
Datos no disponibles
Procedimiento para invitar a los solicitantes a presentar propuestas de proyectos con el objetivo de obtener financiación de la UE.
Régimen de financiación
Régimen de financiación (o «Tipo de acción») dentro de un programa con características comunes. Especifica: el alcance de lo que se financia; el porcentaje de reembolso; los criterios específicos de evaluación para optar a la financiación; y el uso de formas simplificadas de costes como los importes a tanto alzado.
Régimen de financiación (o «Tipo de acción») dentro de un programa con características comunes. Especifica: el alcance de lo que se financia; el porcentaje de reembolso; los criterios específicos de evaluación para optar a la financiación; y el uso de formas simplificadas de costes como los importes a tanto alzado.
Coordinador
CO. Cork
Irlanda
Los costes totales en que ha incurrido esta organización para participar en el proyecto, incluidos los costes directos e indirectos. Este importe es un subconjunto del presupuesto total del proyecto.