41621Y_Vaisala156 6.4.2001 10:09 Sivu 28
Antony Giles, B.Sc.
Product Manager
Eurelettronica Icas Srl
Rome, Italy
Accurate real-time weather monitoring is one of
the most cost-effective ways to promote winter
driving safety. Autostrade Centro Padane (ACP)
has one of the best driving safety records in
Italy, and Vaisala and its Italian agent,
Eurelettronica, are proud to have contributed.
Since 1994, ACP has been using Vaisala’s Ice
products for winter road maintenance.
The ROSA weather station installed close to Brescia.
Autostrada Centro Padane, Italy
Sound Basis for Road Condition
Greater need for winter
maintenance
vation sites for visibility measurement. In addition, the
newly released NowCast forecasting model was installed, together with several IceViewer
software licenses to enable data
to be displayed and used at different locations.
The initial problem to resolve was that of communications: the existing system used
WAN
Met Service
24 hour
forecasts
PWD11
private fixed line
IceViewer for
Windows
ROSA
PWD11
NowCast
PWD11
MILOS 200
modem
A
key factor in the decision to
upgrade it to give more intense
coverage, particularly for visibility measurements, and to
add-on some new and powerful
features. It was decided to increase the number of road
weather stations to six by
adding two new complete
ROSA road weather stations,
and to add a further ten obser-
PWD11
dial-up connection
PWD11
IceCast
UNIX Server
IceViewer for
Windows
ROSA
PWD11
MILOS 200
modem
utostrada Centro
Padane (ACP) operates a 100 km stretch
of motorway between Brescia and Piacenza in
Italy. The motorway passes
through the Pianura Padana, a
vast plain extending across
northern Italy from Turin in
the west to Venice in the east.
Low overnight temperatures,
high humidity and very frequent fog characterize winter
conditions in this area and represent a serious challenge for
safety and winter maintenance.
Autostrada Centro Padane
(ACP) has been using Vaisala
technology since 1994 when
four MILOS 200 road weather
stations were installed in Italy.
PWD11 present weather sensors for visibility measurement
were added to the stations two
years later: in fact, ACP cooperated with Vaisala in field testing a prototype PWD11 prior
to commercial production.
PWD11
MILOS 200
PWD11
PWD11
The high level of satisfaction
with the IceCast system was a
28 156/2001
IceViewer for
Windows
PWD11
MILOS 200
Figure 1. The system architecture. Vaisala’s IceCast server polls the outstations using ACP’s Wide Area Network.
41621Y_Vaisala156 6.4.2001 10:09 Sivu 29
one twisted pair of a private
fixed-line telephone system.
This channel would become
overloaded with all of the new
sites, and no other channel was
available.
Close collaboration between
Panu Partanen and the technical
staff of Vaisala’s Ice Group and
Centro Padane Engineering
staff, i.e. Massimo Balzarini and
Marco Gruppi together with
Technical Director Roberto
Salvadore, led to the design of a
hybrid system architecture. It
left the existing hardware virtually unchanged, and utilized
ACP’s Wide Area Network
(WAN) for communications.
Hybrid system
architecture
As can be seen from Figure 1,
the IceCast server polls the out-
stations using ACP’s Wide
Area Network. Wherever possible, the outstations are connected to the WAN via an
RS232-TCP/IP converter. For
sites which are distant from a
WAN access point, communications are routed through an
originate modem to the private
leased-line.
The NowCast PC automatically feeds forecasts to the
IceCast server using the Local
Area Network (LAN). The
Meteorological Service loads
24-hour forecasts onto the server via a dial-up connection and
standard modem each afternoon. The observed data, 3hour NowCasts and 24-hour
forecasts can all be displayed
anywhere on the network using
the IceCast Viewer for Windows
display software.
NowCasts are 3-hour auto-
The IceView screen showing visibility monitoring in various sites in Italy.
matically generated forecasts of
road surface temperature and
road surface state for specific
sites. The NowCast model uses
real-time data to predict surface
conditions.
24-hour forecasting
Monitoring
The Regional Meteorological
Service of Emilia-Romagna in
Italy manages Vaisala’s IceBreak
heat-balance model. Daily,
throughout the winter season,
forecast meteorological parameters are fed into the model (air
temperature, humidity, wind
speed, cloud cover, etc.) using
the Service’s local area forecast
model. The ForeCaster software
uses the meteorological parameters together with site-speci-
fic physical characteristics (location, altitude, surface type, skyview factor, etc.) to produce a
site-specific surface temperature
and surface state forecast for a
24-hour period.
The combined use of ForeCasts and NowCasts enables
the efficient planning and execution of anti-icing activities
and provides early warning of
potential weather hazards.
New surface sensor
The new ROSA road weather
stations are the first installations of the latest DRS511 road
sensors in Italy. This thermically passive sensor measures road
surface temperature, state and
freezing point, and the incorporated optical sensor directly
measures water thickness in addition to being able to ‘see’ surface ice and snow.
Extensive fog
monitoring
The concentration of PWD11
present weather sensors (a total
of 16, with one every 5 km) enables the ACP operations center to accurately locate and
monitor areas of fog. This information is used to provide
warnings to users via variable
message signs, and to authorize
the opening of roadworks and
the transit of exceptional loads.
This project is a good example of how an IceCast system
can be expanded to integrate
new Vaisala Ice products. Its
success was largely due to the
close cooperation between Vaisala and the customer throughout the project.
■
The MILOS weather station on the foggy bank on the River Po.
156/2001 29