UW – La Crosse

Meteorology
Station

 

Department of Geography

and

Earth Science


 Station Description:

 

            The  Meteorology Station is located on the campus of the University of Wisconsin - La Crosse (UWL). The geographic location of the Meteorology Station is 43 degrees, 48 minutes, 58.5 seconds North, and 91 degrees, 13 minutes, 57.1 seconds West. The station elevation is approximately 203 meters above mean sea level. The Meteorology Station is automated with electronic sensors for solar radiation, net radiation, air temperature, humidity, soil temperature, soil heat flux, wind speed, wind direction, precipitation, barometric pressure.

        Funding for the UWL Meteorology Station has been provided by the UWL Department of Geography and Earth Science, the UWL College of Science and Allied Health, and the UWL Foundation.

 



Instrumentation:

        The University of Wisconsin - La Crosse Meteorology Station currently supports nine instruments. They include a pyranometer, a temperature and humidity probe, an anemometer, a wind vane, a rain gage, and a barometric pressure sensor. Readings from the instruments are recorded on a data-logger and can be down-loaded from a work station in the Department of Geography and Earth Science using a spread spectrum radio. A net radiometer, a soil temperature sensor, a soil heat flux plate

         The Pyranometer measures incoming Solar Radiation with a silicon photovoltaic detector. The detector outputs current and a shunt resistor in the sensor cable converts the signal from current to voltage. This allows the Datalogger to directly measure the signal and to convert the signal from voltage to watts per square meter.

        The Temperature and Relative Humidity Probe contains a platinum resistance temperature (PRT) detector and a capacitive relative humidity sensor. Temperature is measured in degrees celcius and relative humidity in percent.

         The Wind Sentry Anemometer and Vane measure horizontal wind speed and wind direction. The anemometer cup rotation produces an AC voltage signal with a frequency directly proportional to wind speed. Wind speed is measured in meters per second. Wind vane position is transmitted by a precision conductive plastic potentiometer. The output signal is an analog voltage directly proportional to the wind direction azimuth angle.

        The Tipping Bucket Rain Gauge is an adaptation of the standard Weather Service tipping bucket rain Gauge. Output is a switch closure for each bucket tip. A multiplier  in the datalogger program determines the units in which rainfall is reported. Rainfall is measured in millimeters.

    The Barometric Pressure Sensor uses a Vaisala  Barocap silicon capacitive absolute pressure sensor with a 0...2.5 VDC output. Barometric pressure is calculated from the measured output voltage using a simple equation. Pressure measurements are reduced to sea level. Barometric pressure is reported in millibars.

         The Data Logger is a fully programmable data logger/controller in a sealed module. The data logger is accessed with a portable computer. The data logger must be programmed before it will make any measurements. A program consists of a set of instructions entered into a program table. The interval at which the table is executed determines how frequently the sensors are measured.  The UWL Meteorology Station data logger measures the sensors every minute. The interval at which data are stored is separate from the interval at which the table is executed. The UWL Meteorology Station data logger stores data every hour.

         A removable Storage Module supplements the storage capacity of the data logger and is connected to the data logger with a 9-pin peripheral cable. Data can be  retrieved from a storage module without a loss of data to the data logger. Data can also be retrieved from the datalogger with a laptop computer, or hand-held PDA via an infrared port. In the near future, real-time data will be available via the UWL Geography and Earth Science Department WEB page.


Archived Data (Coming Soon)

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