EurOCEAN 2000 - Vlaams Instituut voor de Zee

Fig. 2: Typical TOMOLAB input: Tomographic arrival patterns (left) along a 600-km section
(W3-H) of the Thetis-2 experiment (right) over a period of 9 months.
ƒ The pre-processing toolbox contains tools to perform correlation processing and Doppler
analysis of the raw tomography data. It can be further used for normalization, windowing
and oversampling, as well as for navigation (mooring-motion) and clock-drift correction of
the acoustic data.
ƒ The estimation - identification toolbox addresses the problems of arrival-time estimation,
peak tracking and identification in the pre-processed acoustic data, using manual and
statistical methods. This toolbox is used to convert the pre-processed acoustic data into
travel-time data and identified peak tracks.
ƒ Finally, the inversion toolbox is used to perform slice inversions and estimate averaged
temperature distributions along particular sections. It covers a broad range of inversion
methods, from traditional inversions of the identified peak tracks to simultaneous
identification-inversion of the estimated arrival times (Skarsoulis and Send 2000) and
matched-peak inversions (Skarsoulis 2000).
The above toolboxes have been developed in compliance with particular interface and
integration specifications by 4 different groups (IfM, IACM, LIS and IFREMER), exploiting
the available expertise of each group in the different fields. The interaction of the user with the
toolboxes takes place through a graphical user interface under MATLAB. This interface
contains among others an interactive geographical map, giving an overview of the experiment
geometry on a geographical background and facilitating the definition, selection, and control of
moorings and sections to be processed.
( o C)
(s)
Yearday
Yearday
Yearday Yearday
Fig. 3: Typical TOMOLAB output: The evolution of depth-averaged potential temperatures
along the above Thetis-2 section, compared with historical, CTD and XBT data.
N
42
40
38
36
W1
MARSEI
H W5
S
W4
W2 W3
Algiers
2 4 6 8
Tunis
691