VERY LARGE SCALE MAPPING OF THE ARCHAEOLOGICAL SITE IN CERVETERI (ITALY): DATA 
COLLECTION FROM DIGITAL AUTOMATIC D.T.M., ORTHOPROJECTION AND ANALYTICAL 
STEREOPLOTTING 
Raffaella BOLOGNA, Maurizio MINCHILLI 
Dipartimento di Architettura ed Urbanistica 
Politecnico di Bari 
Via E. Orabona 4, 70125 Bari (ITALY) 
email: minchilli@dau02.poliba.it 
raf@dau02.poliba.it 
Commission VI, Working Group 3 
KEYWORDS: Aerial archaeology, photogrammetry, digital orthophoto. 
ABSTRACT 
The systematic field survey, during the archaeological excavations, is the fundamental methodology to 
archive geometric and qualitative data for stratigraphic analysis. The data collection for cartographic 
purposes are divided, for archaeological use, in three representational levels: territorial, whit scales from 
1:25.000 to 1:5.000; urban, whit scales from 1:2.000 to 1:500 and archaeological details, whit scales from 
1:100 to 1:10 and sometimes 1:1 for smaller objects. 
We test the possibility to use digital large scale orthophotos, at urban scale, for data planimetric collection 
and easy updating of site modifications. The first step has been the construction of detailed 1:2.000 digital 
map of a large area next to the city of Cerveteri; then we try to construct a Digital Terrain Model, using image 
matching tecniques, from the same medium scale photographs used in analytical stereoplotter. The obtained 
geometric data base, with a grid 10x10m, was integrated with manual correlation for20%ca of the points. 
Another aerial coverage, five months later, has shown a changed archaeological site situation with a larger 
photo scale (1:2.300). Also these photos have been automatically correlated, with a grid step of 5x5m, and 
orthoprojected. The construction of the new D.T.M. has been more difficult, because of the bad matching of 
images taken from low altitude aerial coverage. For this reason the new nodes integration has been much 
more expansive (about 50% of 3.027 points). 
1. introduction 
The study of archaeological sites of extension 
larger than 10,000 mq requires the use of 
systematic surveying methodologies of low 
average price, with the contemporary requirement 
of mapping with numerous details structural and 
architectural elements having dense texture. 
The photogrammetric coverage, for archaeological 
purposes, must be executed with schemes that 
greatly vary in relationship to oblique camera axes, 
aerial platforms, use of captive balloons etc.. 
This paper reports on some experiences made 
using normal aerial wide-angle photos of large and 
very large scale. The aerial medium altitude flight 
has been planned to the coverage of the whole 
archaeological site, located to the east of the city 
of Cerveteri near Rome. The aerial photographs, 
taken from a relative height of 1,050 m, have got 
an adequate photo-scale to plottings up to 1: 
2.000. Subsequently, during the normal 
prosecution of the archaeological excavations, it 
has been possible to perform a new aerial 
coverage at very low altitude, with images scale of 
1: 2.300. This kind of photo-recording is very 
critical in the respects of the forward motion, that 
strongly requires the use of F.M.C. film magazine. 
At this very close range from the archaeological 
surface (ca 250 m) the visibility of the smaller 
texture is potentially very high, and the obtainable 
accuracy allow plotting up to 1: 200. 
Later it will be illustrated the experiences 
concerning the analytical plotting for large scale 
and digital image processing for very-large scale 
restitution. 
2. Analytical stereoplotting 
The requirements of the archaeologists, during the 
of excavation progress, have been essentially 
those of a systematic survey on the field for a 
stratigraphy reconstruction of their works. This 
repeatabilty of the photogrammetric 
measurements, very similar to the one present in 
the analyses of the loaded structures deflection, it 
makes the topographic control points survey 
limited only to the first cycle of measures. It results 
in fact very rare that the area of excavation could 
interfere with the location of the artificial targets or 
with that of the photographic points.