CI PA 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
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5. CASE STUDY: THE GRAND RIBAUD ESTRUSCAN 
WRECK 
The Etruscan wreck discovered in 2000 by Mr. H.G. Delauze 
(COMEX, a French commercial salvage and diving company) 
has been dated to the between the 6 th and 5 th century B.C. and 
sits in 60 metres (197 feet) of water off the coast of Toulon, 
France. The archaeological interest in this wreck is 
considerable because only three wrecks of this type are known 
and all had been robbed before being studied archaeologically. 
A first campaign took place in October 2000 with the help of 
COMEX who made available their exploration vessel Minibex, 
their submarine REmora 2000 and a remotely operated vehicle 
(ROV). 
The principal objective of the October 2000 project was to 
obtain digital photogrammetric coverage to record the actual 
state of the wreck and to allow the creation of a site plan and a 
3D reconstruction using simultaneously the observed data, and 
archaeological sources and hypotheses. 
6. THE SURVEY 
An Etruscan amphora found on the Grand Ribaud F wreck, in 
HyEres, France, was surveyed with combines mixed means of 
Laser Scanner and photogrammetry measurement tools. The 
survey took place at the University of Rome 111 in the laboratory 
of architectural representation directed by Prof. Diego Maestri. 
The survey phase can be divided in two main steps: 
1) Laser scanner acquisition: 
14 range scans were acquired with an horizontal step size 
0,125ooand vertical step size of 0,25oo 13 range scans were 
acquired from 13 different positions around the amphora, 
maintaining the amphora in a fixed position through a tripod. 7 
range scans were acquired using the laser scanner tripod 
viewing the amphora top-down. 6 range scans were acquired 
positioning the laser head on the ground viewing the amphora 
from down to top. The range scan viewing the amphora inside 
part was acquired positioning the object in different way. The 
acquisition points were positioned with a maximum distance 
from the amphora of about c.a. 2,7 m. 
2) Photogrammetric acquisition: 
A set of three photographs were taken, without too many 
constraints, from each laser scanner positions and from 2 right 
and left positions in order to guarantee a sufficient base-line. A 
schematic view of the acquisition scheme is reported in 
Figure 3. 
Figure 3. Survey scheme. 
7. DATA PROCESSING 
7.1 Laser scanner data 
After LFR data acquisition and storage the processing steps 
listed in section 3.2 were performed. 
During the pre-processing phase some manual work was 
necessary in order to reduce noise problems especially on edge 
area; due to the laser beam dimension some point are wrongly 
measured were edges between object are present. 
The standard method, based on Iterative Closest Point (ICP) 
algorithm (Besl, McKay, 1992), was used for aligning each scan 
in a single reference system (registration process) The a-priori 
estimation of the relative position between two scans was 
provided using some external reference points manually 
recognized in the reflectance image. 
In order to project the photos acquired centrally from the same 
laser scanner position (see figure 3), the software needs to know 
the external and internal camera parameters. Internal parameters 
can be computed for a specific camera using standard computer