909 
CLOSE PHOTOGRAMMETRY AND LASER SCANNING USING A MOBILE MAPPING 
SYSTEM FOR THE HIGH DETAILED SURVEY OF A 
HIGH DENSITY URBAN AREA 
S. Gandolfi 3 , M. Barbarella 3 , E. Ronci b , A. Burchi b 
a DISTART, Engineering Faculty, 40136 V.le Risorgimento 2 Bologna, ITALY - (stefano.gandolfi, 
maurizio .barbarei la)@mail. ing.unibo. it 
b SITECO INFORMATICA SRL, 40132 Via Della Salute 14 Bologna, ITALY - (ronci, burchi)@sitecoinf.it 
ICWG V/I Integrated systems for mobile mapping 
KEY WORDS: Mobile Mapping System, GPS/INS, LIDAR, GIS, Adjustment 
ABSTRACT: 
The realization of an urban underground is a key issue for the development of any city, and it has to regard all problems linked to the 
project phase and the connections with many other works like railways, bus-lines and, specially for an ancient city like Bologna, 
historical buildings.For these reasons the Municipality of Bologna has committed the ultimate design of the underground line with a 
high standard level of precision; this aspect forces the Project Group to choose a survey method that has to be both accurate and not 
too expensive. In order to achieve a precise high resolution survey in a short time, a Mobile Mapping System vehicle has been used. 
The Road-Scanner” system is equipped with 2GPS+IMU sensors for navigation (Applanix POSLV), four cameras for close range 
photogrammetric survey and a Laser scanner FARO LS880. Moreover, in order to obtain good and homogeneous results a geodetic 
network (performed using GPS and topographic survey) has been made in some area along the track. In this contribute the authors, 
starting from the municipality requirements, describe all the performed work and analyze the obtained results. 
1. INTRODUCTION 
During the last years the Municipality of Bologna (Italy) has 
been involved in the realisation of the first stretch of the urban 
underground. In the same period the high-speed railway project 
has been carried out in Italy. It also crosses the city of Bologna 
which is, for geographic reasons, a historical fundamental 
junction in the Italian railway traffic. This project is completely 
autonomous from the previous one but it is mandatory that the 
two projects share the same reference system and frame. For the 
realisation of this high detailed survey in very short time a 
Mobile Mapping System (MMS) has been used. The vehicle, 
using a satellite navigation system (GPS) assisted whit an 
Inertial Measurement Unit (IMU), permits to localise points 
surveyed both by photogrammetry and laser scanner directly in 
the Italian National Geodetic Reference Frame IGM’95 
(derived from the ETRF89 System). 
1.1 General Information on the surveyed area 
The project line length is about 7,5 km and links the Fair Centre 
and “Maggiore” Hospital. Obviously, the “Centrale” Railway 
Station and the City Centre are involved; a scheme of the track 
is shown in Figure 1. 
Even if the underground project is autonomous from the high 
speed railway project (TAV), there will be some relationships 
between the two projects. Therefore the Project Group has 
chosen to share the same reference system and the frame. The 
MMS surveys have been referred to the Italian National 
Geodetic Reference Frame IGM’95 (derived from the ETRF89 
System). 
Fair 1 
Figure 1. Underground track and stations 
The transformation between the two systems (TAV and 
GPS/ETRF89) was determined by classical approach . 
1.2 Requested product 
In order to obtain a complete product the project specifications, 
requested by public administration, are very restrictive and the 
final product must correspond at least to the following points: 
1. Sub-decimetre precision (both for planimetry and altimetry) 
2. Final results must be referred to both TAV reference frame 
and UTM-ED50 frame 
3. The drawings must contain the high detailed survey of the 
station areas and the inspection wells (10 inspection wells 
were provided for this project) 
4. All the drawings must contain at least: 
A. Reference points and vertexes 
B. Buildings 
C. Fences