海洋气象监测

CSI on deck means real-time reportsfor the Washington State Ferry System
Sound monitoring:  Mobile weather stationsprovide data tothe public

The Washington State Ferry　System (WSF) is the largest　ferrysystem in the United　States.  The 29-vessel fleet makes　over500 trips per day,　facilitating　transportation ofcommuters,　tourists,　vehicles,　and goods to islands and　peninsulasthroughout Puget Sound.　Weather systems in the area move　from thePacific Ocean across western　Washington,　with wind speedand　direction on the waters of Puget　Sound being influenced bythe　Olympic and Cascade mountain　ranges. Surface winds areoften　deflected or funneled contrary to the　barometric flow of thesystems.　Personal observations of pilots,　Washington State Ferrycaptains,　and　other mariners have shown weather　conditions on theSound to be vastly　different,　at times,　from those being　recordedby National Oceanic and　Atmospheric Administration(NOAA)　shore　side sensors,　and by four buoy　stations in the areaoperated by the　National Weather Service.　In an effort to makemeteorological　data from the Sound available to the　public,　theWashington State　Department of Transportation funded　theinstallation of weather stations on　seven of the ferries.  Thestations mea-sure meteorological parameters along　the ferry routesand provide ferry　operators and the general public with data formore accurate weather reports　and forecasts.  The stationsprovide meteorological data where such data was previouslyunavailable due,　in part,　to the　unique geographic andenvironmental features of the region.　In 1995,The Universityof　Washington,　School of Marine Affairs　established the SmartForum,　instituting a　means for federal,　state,　and local regulatorsto exchange information with marine　operators,　managers and thegeneral public about safe marine transportation in　PugetSound.  The involvement of　Campbell Scientific,　Inc.,　inplacing　weather stations on the ferries,　was a　direct result of theSmart Forum.　The weather stations were integrated　into the alreadyexisting Fleet Location　System (FLS),a real-time ferrytracking　system used by the WFS to maintain the　exact locations ofeach ferry and coordinate scheduling.  MeteorCommunications　Corporation (MCC) provided the FLS　with CampbellScientific equipment and　in turn integrated the weather stationsinto　the FLS systems of the ferries.　Each station consists of aCR10X data-logger which measures air temperature,　barometricpressure,　relative humidity,　and wind speed and directionsensors.  A　Global Positioning System (GPS) pro-vides globalposition coordinates,　vessel　speed over ground and courseover　ground.  A gyrocompass (GYRO) pro-vides the actual vesselheading.  Data　from the GPS,GYRO and CR10X are　input to aMCC-545A RF modem,　which　corrects the measured wind speedand　direction using the vessel speed,　heading　and course overground.  The RF modem　outputs the corrected wind speedand　direction back to the CR10X for display　on the panel,　thentransmits a data report.　The data are displayed to the ferrycaptain　on the vessel itself through use of an LED　display panelinterfaced to the CR10X.Data are also delivered to aWashington　State Ferry work　station,　and are available　fordissemination to the NWS and the　University of Washington,　inaddition to　being posted to the Washington State　Ferry web page forpublic use.　During periods of high winds and maximum tidalcurrents,　some ferries are pre-vented from safely landing at,　ordeparting from,　their terminal slips.  With a single delaycausing dramatic concern for　thousands of commuters,　theinstallation　of weather stations on some ferries and　transmissionof the subsequent real-time　data fills a critical gap in theever-changing puzzle that is Puget Sound weather.

The Washington State　Department ofTransportation,　in conjunction with the　University ofWashington,　posts data from the ferries on　its web site (seeaddress above)in near real-time.  Arrows　indicate winddirection and　speed (in knots).

The content of this Application-at-a-Glance was obtained (withpermission)from the following sources.  The reader is　referredto these documents for a more　complete discussion of theapplication　and the methods used:　Richard J.Fulthorp,　BSEE,　Meteor　Communications Corporation,(MCC)Software　Engineering,“　Washington State Ferry Mobile　WeatherStation.”　Copyright January,2000.Joseph Nortz,　Washington StateFerries,　and Jay　Creech,　Meteor Communications Corporation,“　PugetSound Wind Speed Data Collection　System.”　CopyrightAugust,1999.