Examining Atmospheric Effects on FDOT Microwave Transmissions
And Providing Travel Weather to Florida Citizens (Phase II)
Research Sponsored by the
Florida Department of Transportation
Subcontracted through the University of North Florida
The FSU portion of this research is being conducted with Profs. Bing Kwan and Simon Foo in the Department of
Electrical Engineering and with Prof. Jim Elsner in the Department of Geography. The material below gives overall
information about the project and focuses on the contribution of our lab.
The Florida Department of Transportation (FDOT) Microwave Communications System consists of 71 microwave paths
along most of Florida's Interstate road system as well as the Florida Turnpike. The system provides voice and data
connectivity for the FDOT and Florida Highway Patrol (FHP) facilities that are co-located with the microwave
installations. During Phase I of the project, approximately 15 microwave tower sites were instrumented with basic
meteorological sensors by the prime contractor, The University of North Florida (UNF). In addition, three additional
sites were equipped with higher resolution weather sensors at multiple levels. The remaining 71 sites will be
instrumented at one or more levels during Phase II and later years.
The additional meteorological information will be provided to the traveling public through the MyFlorida.com website,
allowing motorists to plan their trips more carefully, avoiding possible hazardous weather such as dense fog and heavy
rain. We will continue to develop ways to infer the presence of dense fog at tower locations that do not have
visibility sensors. In addition, we will continue to develop procedures to utilize the new meteorological data in
weather forecast models that will lead to improved forecasts for the citizens of Florida. Finally, the proposed
system will provide valuable weather information to the Florida Emergency Operation Center (EOC), the National
Hurricane Center (NHC), and the National Weather Service (NWS) offices throughout the State.
Forecasting Hazardous Travel Weather
While it is important to know whether fog or some other hazardous traveling weather currently is occurring, it
also is important to know whether such conditions are expected to occur during the hours ahead. For example, a
motorist might wish to leave Tallahassee at 7 PM and arrive in Ocala at 11 PM. However, if he/she would log onto
the MyFlorida.com web site and learn that dense fog was expected along the route before 11 PM, the motorist might
decide to change those plans, moving up the departure to avoid the hazards associated with the fog. Travelers
might also change their plans due to expected heavy rain or intense lighting. Even if travel plans cannot be
changed, it still is useful to know the weather conditions that will be encountered along the way.
Meteorologists use computer models to assist in preparing weather forecasts. These models couple
existing conditions with physical equations of the atmosphere to forecast conditions at future times. As
computing capabilities have grown over the years, these models have been able to operate at finer and finer
resolutions. For example, many current models have horizontal resolutions less than 10 km.
The weather forecast models benefit greatly from having a dense network of current observations. That
is, the better the data that are input to a forecast model, the better is the weather forecast that results.
Since the FDOT weather sensors at microwave towers are being placed at ~ 20 mile intervals along the interstates
and other major highways, they provide a major new source of data for the computer models that will lead to
improved weather forecasts. The challenge is to correctly incorporate these data into the forecast models.
We will continue to develop procedures to incorporate the FDOT data into computer forecast models. We
will utilize the Local Analysis and Prediction System (LAPS). LAPS combines nationally disseminated data with
local data for real-time objective analyses. The local data for this project will come from the FDOT sensors and
all other available sources. Local radar data and satellite imagery also will be utilized. The LAPS output is of
suitable quality to initialize a local-scale forecast model that can address specific problems of a small
forecast domain with greater detail than can be achieved with nationally disseminated model guidance. We are
collaborating with the National Weather Service offices in Florida in conducting this research since they also
have a strong interest in improved local forecasts.
Our goal is to provide improved high resolution detailed weather forecasts for the motoring public. By
inputting the FDOT data into the forecast models, improved short-term forecasts can be obtained. These forecasts
can be made available to the public through the MyFlorida.com web site. Thus, they can be used to plan trips.
Furthermore, if terminals become available at rest stops along the highways, the MyFlorida.com site could be used
to provide updates about conditions that will occur at locations ahead.