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Sessions
versatility and using the bus power lines avoid external power supply
for each device.
INSTRUMENTATION VIEWPOINT
106
Multiple cameras image acquisition is not supported by the software
driver NI-IMAQ for USB Cameras for LabVIEW. This problem we have
solved with Matlab and the image acquisition toolbox. Since is possible to call Matlab scripts from LabVIEW we have integrated all the interface, system acquistion control and data treatment in LabVIEW. At
the moment only the images are stored, we are working for a vision
alogrithm and a subtract of equidistant images are giving hopeful results and will permit to contrast and complement the results already
obtained with infrared barriers.
Fig. 2. Complete system structure
A laptop cumputer with a LabVIEW application developed [7] controls
all the subsystems and stores IR signal and image data, also treats
and processes the data applying a detection algorithm that uses an
adaptative threshold to improve results. Finally a remote server application permits control the system and visualizes the experiments
through Internet.
Results
Six successful experiments have been done up to the present and
processed data is being analyzed by the biologists. These investigators are inding enlightening results of the emergence activity biorhythms of the Nephrops Norvegicus useful for their research and will
be published in a near future. The irst conclusions during the irst
analysis are that activity is noticeably nocturnal and the same behavior is repeated day after day following a pattern.
Conclusions
A distributed system has been developed, this design ofers great
lexibility and is easily expandable; it is enough repeating the subsystems necessary and connects them to the central computer throught
USB ports. Two were the interfaces that adjusted to this design: USB
and Ethernet, we implemented with the irst one because gave more
Is important to indicate that the system can be used in other biological experiments solving and ofering a nonexistent technology in the
market.
Acknowledgements
The system development has been possible thanks to the Incidence of Norway lobster (Nephrops norvecigus L.) emergence activity rhythms on its population assessment (CTM20055-02034/MAR)
project, funded by the Spanish Ministry of Education (MEC), and is a
joint work between the Marine Institute (CSIC) and the Polytechnical
University of Catalonia (UPC) Associate Unit Tecnoterra.
References
[1] E.L. Dereniak, G.D. Boreman, Infrared detectors and systems, 1996, John
Wiley & Sons.
[2] E.R. Loew, Light and phtoreceptor degeneration in the Norway Lobster
Nephops norvegicus (L.), 1976, Proc. R. Soc. London B. 193:31-44.
[3] N.G. Jerlov Optical Oceanography, 1968, Elsevier, Amsterdam.
[4] J.M. Angulo, S. Romero, I. Angulo, Microcontroladores PIC, diseño práctico
de aplicaciones, segunda parte, 2000, Mc Graw Hill.
[5] J. Axelon, USB Complete. Everything you need to develop custom USB peripherals, 2005, Lakeview Research
[6] A. De la Escalera Hueso, Visión por computador, fundamentos y métodos,
2001, Prentice Hall.
[7] A. Mànuel, J. del Río, LabVIEW 7.1 Programación gráica para el control de
instrumentación, 2005, Thompson.
COASTAL DYN AM I CS I N STRUM EN TATI ON I N THE BASQUE
COUN TRY REGI ON
J. Mader, A. Fontán, L. Ferrer, M. González and Ad. Uriarte
AZTI-Tecnalia, Unidad de Investigación Marina, Herrera Kaia, Portualdea, 20110 Pasaia, Gipuzkoa, SPAIN,
e-mail: jmader@pas.azti.es
Keywords: Coastal station, Oceano-meteorological network, Current patterns, Instrument intercomparison.
One of the main objectives of Operational Oceanography is to obtain organised and long-term routine measurements of the seas,
oceans and atmosphere, and provide their rapid interpretation and
dissemination [1] [2] [3]. Variables such as marine currents, sea temperature and salinity, wave height and period, wind stress, heat luxes
between atmosphere and ocean are fundamental to get an accurate
description of the marine and atmospheric environment, and therefore, bring an eicient Operational Oceanography System on stream.
This information can be obtained by means of appropriate instrumentation, which must be of an accurate and robust quality and this
requires routine maintenance tasks.
The oceano-meteorological instrumentation network in the Basque
Country region (Fig.1) consists of: 1) six coastal oceano-meteorological stations located at Bilbao, Bermeo, Ondarroa, Getaria, Pasaia, and
Hondarribia; 2) two ofshore buoys (Wavescan), moored of Matxitxako and of Donostia, at 550 m and 450 m water depth, respectively,
which provide real time data of the main oceanic and meteorological
variables at ixed points, giving reference information for the Basque
coastal and oceanic regions (http://www.azti.es; http://www.euskalmet.net ).
This study has been focused on data from the pilot coastal station, set
up in 2001 in front of the entrance to the harbour of Pasaia (Fig.1). The
location selected for the station is a light post which is mounted on a
rigid structure attached to the seabed at 25m water depth. Six years
time series of meteorological parameters, water temperature and currents over the water column have been processed with speciic tools
of quality control, statistics and components analysis. In particular,
local patterns of currents have been described by studying the correlation between wind and surface currents. The information obtained
from surface tracking with a bottom mounted current proiler can be
very useful for modelling satisfactory wind driven circulation.
mented in 2008 with the addition of a high frequency radar system,
which will provide information of current ield, with a resolution of
6 km.
References:
For the corresponding instrumentation, this work included intercomparison between the bottom mounted ADCP Aanderaa DCM12 of
the Pasaia station and a RDI WH600. Both were used for water proiling and surface tracking.
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Moreover, the littoral patterns measured in Pasaia station have been
compared to ofshore patterns observed with the recently moored
buoy ofshore Donostia (from January 2007). The understanding of
coastal particularities can be a key point for improving hydrodynamic
modelling [4] [5]. In that context, the observing system will be imple-
Sessions
Figure 1: Study area with coastal and ofshore stations of the
Basque Meteorological Agency network.
[1] Behrens H.W.A., J.C. Borst, J.H. Stel, J.P. van der Meulen and L.J. Droppert.
1997. Operational oceanography, Proceedings of the irst international conference on EuroGOOS, 7-11 October 1996, The Hague, The Netherlands. Elsevier Oceanography Series 62: 757pp.
[2] Dahlin H., N.C. Flemming, K. Nittis and S.E. Petersson. 2003. Building the
European capacity in operational oceanography, Proceedings of the third
international conference on EuroGOOS, 3-6 December 2002, Athens, Greece.
Elsevier Oceanography Series 69: 714pp.
[3] Flemming N.C., S. Vallerga, N. Pinardi, H.W.A. Behrens, G. Manzella, D.Prandle
and J.H. Stel. 2002. Operational oceanography: implementation at the European and regional scales. Proceedings of the second international conference
on EuroGOOS, 11-13 March 1999, Rome, Italy. Elsevier Oceanography Series
66: 572pp.
[4] Fontán, A., J. Mader, M. González, A. Uriarte, P. Gyssels and M. Collins, 2006.
Hydrodynamics between San Sebastián and Hondarribia (Guipúzcoa, Northern Spain): ield measurements and numerical modelling. Scientia Marina.
volume 70 (Suppl 1) of Scientia Marina
[5] González, M., A. Uriarte, A. Fontán, J. Mader and P. Gyssels, 2004. Marine
Dynamics (In Oceanography and Marine Environment of the Basque Country),
Elsevier Oceanography Series nº70, 133-157
M ULTI FRACTAL AN ALYSI S OF SAR OF THE OCEAN SURFACE,
CURREN TS, EDDY STRUCTURE, OI L SLI CKS AN D
DI FFUSI VI TY AN ALYSI S
J.M. Redondo(1) J. Grau(2), A. Matulka(1) and A. Platonov(1)
(1) Departament de Fisica Aplicada, B5 Campus Nord
Universitat Politecnica de Catalunya, 08034, Barcelona, Spain.
Tf:34 934016802, Fax:34 934016090, Redondo@fa.upc.edu.
107
(2) Departament de Mecanica de Fluids, UPC, Barcelona.Spain.
2. Results and Discussion
Experimental and Geophysical observations are investigated with
multiscale fractal techniques in order to extract relevant information on the spectral characteristics of mixing and difusive events.
Both density and tracer marked oil spills and slicks are investigated
in detail using third order structure function analysis that indicates
strong inverse cascades towards the large scales producing spectral
variations [4]. The diferent local mixing processes are compared by
mapping their diferent multifractal scaling. Several uses of this new
technique are proposed [5-8] taking advantage of Zipf’s Law, both
for anthropogenic oil spills and other features, it is possible to predict
the likely probability of oil spill accidents of diferent sizes, as well as
the local eddy characteristics that strongly inluence the turbulent
horizontal difusivity, K(x,y).
(a)
(b)
Figure 1. Example of an oil spill afected by a local vortex south of
Barcelona.
a) SAR ENVISAT frame.
b) detail at higher resolution
Both numerical simulations [4] and laboratory experiments conirm
the conditions for hyperdifusion ( D 2 = c t n(f,N) with n(f,N) > 3 ) to
exist, as well as the trapping associated with coherent structures and
vortices in the ocean, which are well detected under the Weilburn
distribution of prevailing winds in the NW Mediterranean Sea..
INSTRUMENTATION VIEWPOINT
1. Introduction
The use of Synthetic Aperture Radar (SAR) to investigate the ocean
surface provides a wealth of useful information. Here we will discuss
some recent fractal and multifractal techniques used to identify oil
spills and the dynamic state of the sea regarding turbulent difusion.
The main objectives is to be able to parametrize mixing at the Rossby
Deformation Radius and aid in the pollutant dispersion prediction,
both in emergency accidental releases and on a day to day operational basis. Results aim to identify diferent SAR signatures and at the
same time provide calibrations for the diferent local conigurations
that allow to predict the behaviour of diferent tracers and tensioactives in the sea surface difused by means of a Generalized Richardson’s Law [1-3]. The difusion of oil spills and slicks in the ocean
(Figure 1) have been also investigated using the same multifractal
techniques developed by [1, 3]. Diferent cases are studied analyzing
mixedness, and multifractality [2].