The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008 
910 
D. 
Works of art 
E. 
Sidewalks 
F. 
Road signs 
G. 
Manholes 
H. 
Traffic lights 
I. 
Trees 
J. 
Garages 
K. 
Private accesses 
L. 
Electric lines 
M. 
Generic Service Lines 
N. 
All not specified but helpful to the representation 
of the territory 
The time limit for the end of survey operation was not grater 
than 30 working days. For this reason the Project Group has 
moved from 
the starting idea of a classic survey to the 
possibility to 
use a Mobile Mapping System. 
2. SURVEY EQUIPEMENT AND METHODOLOGY 
2.1 Road-Scanner system 
“Road-Scanner” is a MMS (Mobile Mapping System) vehicle 
equipped with many different sensors able to perform very high 
detailed survey along the trajectory that the vehicle is moving. 
The Road-Scanner system was realized, at the beginning for the 
implementation of road inventory, in agreement with the Italian 
law (Italian D.M. 1 June 2001) but can also be employed in all 
the applications that require high detailed survey with quite 
good accuracy (decimeter level accuracy). 
In detail the Road-Scanner is equipped with 2GPS+INS sensors 
for navigation (Applanix POSLV 220 System), four digital 
cameras (Imaging Source) for close range photogrammetric 
survey, a Laser scanner (FARO LS880), a OMNISTAR 
receiver (Trimble AG332) and a Road surface profiler (this 
sensor was not used for the underground survey since not 
requested). 
This system allows achieving a full inspection of all the 
infrastructure components by acquiring automatically several 
data sets like: 
1. Vehicle route 
2. Longitudinal profile 
3. Pavement roughness (IRI - International Roughness Index) 
4. Geo-referenced images at a 1-4 meter step 
5. Geo-referenced laser point clouds 
Figure 2. Road-Scanner System 
All the data sets are geo-referenced by means of the powerful 
Applanix POS-LV positioning system. Thanks to that, they are 
all related and can be accessed and edited with the post 
processing application. The Figure 2 and 3 shows the Road- 
Scanner system and an example of a geo-referenced laser points 
cloud. 
The Applanix system combines GPS sensors and IMU using a 
Kalman filter and permits for every epoch to give position and 
orientation of the vehicle. The photogrammetric unit and the 
Laser Scanning determine the position of the surveyed points in 
a reference frame rigidly connected to the body of the vehicle 
time by time. 
P ■■—uà 
Os#»« t fc. * * « » ** * . . ’ if #*<*•« 
Figure 3. Geo-referenced laser points cloud 
So, in theory, is it possible to define a transformation matrix 
that permits the determination of the position of both the 
typology of instrument (and hence the position of the surveyed 
points) in the reference frame defined by the Applanix system. 
2.2 Sensors specification 
The Table 1. shows the sensor specifications as reported by the 
producers: 
Sensors 
Specification 
Laser Scanner: 
FARO LS880 
At 25m 3mm 
Navigation System 
POSLV220 
60 sec GPS outage 
XY position 
15mm 
Z position 
20mm 
Roll & Pitch 
0.06° 
True heading 
0.03° 
Table 1. Some sensor specifications 
The values reported, concerning the POS LV 220 System, are 
referred to a 60-second of complete GPS signal outage. When 
the GPS signal is available the precision corresponds to the 
kinematic post-processed approach when the fixed solution is 
available (typically 2-5 cm).