DIGITAL PHOTOGRAMMETRY AND LASER SCANNING 
IN SURVEYING THE “NYMPHAEA” IN POMPEII 
Gabriele Bitelli a , Alessandro Capra b , Antonio Zanutta a 
a DISTART, University of Bologna, Viale Risorgimento 2, 40136 Bologna, Italy - 
(gabriele.bitelli, antonio.zanutta)@mail.ing.unibo.it 
b DAU - Polytechnic of Bari, Via Orabona 4, 70125 Bari, Italy - alessandro.capra@mail.ing.unibo.it 
Commission V 
KEY WORDS: Cultural Heritage, Close Range, Digital Photogrammetry, Laser Scanning, Surface Modelling 
ABSTRACT: 
A study currently carried out with archaeologists from Bologna University involves the restitution of the nymphaea existing in 
Pompeii (Naples, Italy); this task requires a long work using classical photogrammetric techniques. Different solutions were tested 
using digital photogrammetric systems, in terms of data acquisition (e.g. semi-metric vs digital cameras, Cyclop system), data 
processing (e.g. automated surface model reconstruction, monoscopic or stereoscopic plotting) and representation (e.g. orthophotos, 
adoption of cartographic projections), but this kind of object could be an interesting application also for laser scanning techniques. 
The decoration of nymphaea apsidal and front walls is particular rich in some cases, and deformation of surfaces are sometimes well 
evident, so the integration of the opportunities provided by close range digital photogrammetry and laser scanning could be a topic of 
interest. A multi-station laser scanner survey could permit to complete the planned activity in shorter time and with an adequate 
accuracy, with the production of a complete 3D model; this solution has been tested through the comparison with digital 
photogrammetric survey in terms of precision and reliability in restitution of the object size and shape, with the final aim to 
understand what kind of solution better supports the study and the accurate metrical documentation of the nymphaea. The paper 
presents the test currently carried out on two nymphaea. 
1. INTRODUCTION 
The research here described regards a project started in 1999, 
within a collaboration established between the University of 
Bologna and the Archaeological Superintendence of Pompeii. 
The project pointed out originally the study, restoration and 
valorisation of the Centenary Insula (IX,8), regarding an 
interesting house known as “of the Centenary” that would be 
scientifically recuperated and made available (Scagliarini 
Corlaita and Coralini, 2002). 
In the frame of this project was successively activated a 
rigorous survey by digital photogrammetry of the most 
significant nymphaea of Pompeii. The nymphaea are elements 
of remarkable archaeological and also artistic value. Important 
houses of Pompeii were decorated with nymphaea. Like other 
structural elements they showed the social and economical 
status of house proprietary, so the pictures on walls and apsidal 
and the material used were sometimes particularly fine, giving 
artistic value to the objects. In Pompeii area about 15 examples 
of nymphaea are known, characterised by different geometry 
and structure. During 1999 and 2001 campaigns the surveys of 
six nymphaea were carried out, located in Centenary house, 
Grand Duke house, Small And Big Fountain houses, Wounded 
Bear’s house, Scientist’s house. 
The nymphaea have been chosen with the aim to furnish almost 
an example of every architectural and decorative typology, so a 
preliminary phase was planned to study surveying and 
representation methodology appropriate for each specific 
typology based on the geometrical characteristics of nymphaea. 
The research in those phase regarded the survey and restitution 
through the utilisation of digital photogrammetric methods, 
evaluating alternative techniques by means of direct 
photogrammetric comparisons (Bitelli et al., 2001). The 
research is not concluded and in 2002 campaign further 
processing and data acquisition for other nymphaea is planned. 
The photogrammetric restitution produced 3D object model and 
raster products. An high degree of detail was maintained in the 
image acquisition and plotting process, trying to preserve the 
richness of nymphaea apsidal and walls decoration in the 
graphical representation. Even the deformation of nymphaea 
surfaces are in some cases well evident. 
In order to verify the reliability of different techniques of 
investigation with respect of richness and detail object 
description and eventual deformation detection, the integration 
of different close range digital photogrammetry techniques and 
laser scanning was planned. The latter is certainly an emerging 
technique for industrial and architectural applications, as well as 
in the field of cultural heritage and virtual reality based 
museums (Beraldin et al., 1999; Bôhler et al., 2001; Monti et 
al., 2001). 
A multi-station laser scanner survey could permit to complete 
the planned activity in shorter time and with an adequate 
accuracy, with the production of a complete 3D model. 
The solution has been tested through the comparison with 
digital photogrammetric survey in terms of precision and 
reliability in restitution of the object size and shape. 
The different techniques were pointed out to understand which 
solution could better supports the study and the accurate 
metrical documentation of the nymphaea in respect to 
geometrical and artistic typology. 
The current work will be briefly described in the next 
paragraphs, taking as example the survey of the nymphaea of 
the “House of the Big Fountain” and of the “House of the Small 
Fountain” (fig.l). 
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