Weather Station Equipment
The Goose Lake Weather station consists of a Davis Weather Instruments Vantage Pro2 Plus wireless weather station and wireless soil temperature and moisture station. In addition, a manually read CoCoRaHS rain gauge is used to supplement the automated rainfall readings. Whenever possible, siting of weather sensors was done following established guidelines as detailed in the CWOP Weather Station Siting, Performance, and Data Quality Guide in order to provide the most accurate data.
Temperature and Humidity
The Integrated Sensor Suite(ISS) contains the temperature and humidity sensors. Temperature is measured using a thermistor. The thermistor has a range of -40° to +150°F (-40° to +65°C) and an accuracy of ±1°F (±0.5°C). Temperature readings are updated every 10 seconds. Humidity is measured using a film capacitor element. The humidity sensor range is 0 to 100% RH. Accuracy is ±3% (0 to 90% RH), ±4% (90 to 100% RH). The update interval for humidity is 50 seconds to 1 minute. Dew point is calculated from humidity and has an accuracy of ±3°F (±1.5°C). The dew point update interval is 10 to 12 seconds. A daytime fan aspirated radiation shield is attached to the ISS to provide better airflow around the sensors.
Wind data is provided by the anemometer and wind vane. The main wind equipment is located on a tower approximately 35 ft above the ground. A second wind sensor is located above the ISS. Wind speed information is provided by the anemometer. Wind speed is measured in 1 mph units. Other units are converted from mph and rounded to nearest 1 km/h, 0.1 m/s, or 1 knot. Wind speed range is 2 to 150 mph, 2 to 130 knots, 1 to 67 m/s, 3 to 241 km/h. Update intervals are 2.5 seconds for instantaneous readings. The 10-minute Average wind speed is updated at 1 minute intervals. Accuracy is ±2 mph (2 kts, 3 km/h, 1 m/s) or ±5%, whichever is greater. Wind Direction is measured with the wind vane. The wind vane has a resolution of 16 points (22.5°) on compass rose, 1° in numeric display. The accuracy is ±4°, and update interval is every 2.5 seconds.
Rainfall is measured by the automated rain gauge with a tipping-bucket type mechanism. The rain gauge measures rainfall in 0.01 inch increments.
Accuracy for rain rates up to 2"/hr (50 mm/hr): ±4% of total or +0.01" (0.25 mm)(0.01" = one tip of the bucket), whichever is greater. For rain rates from
2"/hr (50 mm/hr) to 4"/hr (100 mm/hr): ±5% of total or +0.01" (0.25 mm) (0.01" = one tip of the bucket), whichever is greater. The rainfall update interval is
10 to 12 seconds.
Special Note Regarding Rainfall Data: Automated rain gauges tend to underestimate heavy rainfall events. At times, the tipping mechanism cannot keep up with the heavy rainfall. The automated rain gauge is not heated and therefore of limited value in the winter months. The Goose Lake Weather Station also uses manually read rain gauges to record rainfall as well as snowmelt in the winter as noted below. Please note that the rainfall values updated automatically on our web page are from the automated rain gauge and therefore may not always accurately reflect the total rainfall as measured by a manual gauge.
Manual CoCoRaHS Rain Gauge and Snow Data
In addition to the automated rain gauge, we use a manual CoCoRaHS certified rain gauge to supplement the automated readings. The CoCoRaHS gauge has a 11 inch capacity
and has proven to be a very accurate gauge. This manual gauge is also used in winter to determine the water equivalent of new snow and core samples of the total
snow depth. Data is submitted daily to the CoCoRaHS network. Our station number is IL-GY-1.
Learn more about CoCoRaHS.
Snowfall is measured the old fashioned way -- with a snow stick measured in 0.1 foot increments. Snow boards are used to facilitate new snow and total snow readings when conditions are ideal. Windy conditions with drifting snow require several readings in representative areas that are averaged to determine the depth.
Solar and UV Data
The Solar Radiation Sensor, or solar pyranometer, measures global radiation, the sum at the point of measurement of both the direct and diffuse components of solar
irradiance. The sensor’s transducer, which converts incident radiation to electrical current, is a silicon photodiode with wide spectral response. From the sensor’s
output voltage, the console calculates and displays solar irradiance. It also integrates the irradiance values and displays total incident energy over a set period of time.
1 W/m2. The sensor range is 0 to 1800 W/m2, and accuracy is ±5% of full scale (Reference: Eppley PSP at 1000 W/m2). Sensor drift is up to ±2% per year. the update
interval is 50 seconds to 1 minute.
The Davis Instruments UV Sensor is a precision instrument that detects ultraviolet (UV) radiation at wavelengths of 290 to 390 nanometers. The spectral response is closely matched to the Erythema Action Spectrum, defined by McKinlay and Diffey (1987) and internationally recognized as the radiation that is most responsible for causing redness of the human skin. The Davis Instruments Solar Radiation Sensor is a precision instrument that detects radiation at wavelengths of 300 to 1100 nanometers. The spectral response of the silicon photodiode detector is a good match to the spectrum of solar irradiance. The UV sensor has a range of 0 to 16, and an accuracy of ±5% of full scale. The update interval is 50 seconds to 1 minute.
Soil Temperature and Moisture
A recent addition to the Goose Lake Weather Station was soil temperature and soil moisture sensors. The Watermark® soil moisture sensor is an indirect, calibrated method of measuring soil water. It is an electrical resistance type sensor. The Vantage Pro2 weather station converts the electrical resistance reading from the sensor into a calibrated reading of centibars (cb) of soil water suction. The soil moisture sensor has a range of 0 to 200 cb and an update interval of 62.5 to 75 seconds. The Watermark soil moisture sensor is a product of the Irrometer Company, Inc. The soil temperature probe is a precision thermistor that produces a resistance change proportional to temperature. The temperature probe is used by the station to provide temperature compensation for the associated soil moisture reading. The resolution of the soil temperature probe is 1°F or 1°C. It has a range of -40° to +150°F (-40° to +65°C) and an accuracy of ±1°F (±0.5°C). The update interval is 10 to 12 seconds.
The station pressure sensor is housed inside the Vantage Pro2 Console. Pressure is measured in 0.01" Hg. The corrected range is 26.00" to 32.00" Hg, 660.0 to 810.0 mm Hg, 880.0 to 1080.0 hPa/mb. The update interval is 15 minutes, and accuracy is ±0.04" Hg (±1.0 mm Hg, ±1.4 hPa/mb).
Vantage Pro2 Console
The Vantage Pro2 console displays and records weather data, provides graph and alarm functions, and interfaces to the Goose Lake Weather Station computer using the Davis datalogger and WeatherLink® software. The console receives the wireless transmissions from the ISS and wireless soil temperature/moisture station.
Webcam images are provided by an Axis 207W (wireless) web cam.
The latest addition to our weather equipment was a Boltek StormTracker lightning detection system. The system consists of a PCI board/receiver installed in our desktop computer and a small antenna mounted in the attic.
StormTracker works by detecting the radio signals produced by lightning. These are the same signals you can hear on an AM radio during a thunderstorm. StormTracker's direction-finding antenna provides direction information while storm distance is calculated from received signal strength. Special processing in software reduces the effects of strike-to-strike energy variations providing more accurate distance information. Astrogenic Systems' NexStorm software is used to display, archive, and upload graphics to our web page.
Note: The StormTracker provides useful lightning data for monitoring nearby thunderstorm activity. Is is important to note that a stand alone hobbyist level detector provides approximate data and cannot be compared to more sophisticated (and considerably more expensive!) lightning detectors used in nationwide detection networks. The data is only approximate and should not be used for safety applications. Strike and storm locations indicated and alarm statuses may be erroneous and should not be used to safeguard personnel, equipment or data. Do not use for human safety or protection of property purposes.