Quality Assurance
This page describes factors that influence the quality of data from the Tesa WS1081V3 AWS, and also outlines our routine performance monitoring. Although we strive to provide the highest quality data, you should never base important decisions on the data we publish or provide. The page also describes issues with the Weather Display software that affect our operations.
This page should be viewed in conjunction with our station metadata and observing program for a complete overview of our standard operations.
Tesa WS1081V3
Rainfall
The AWS rain gauge has a resolution of 0.3 mm and is used for all real-time reporting. The standard rain gauge is read to 0.1 mm and is used for all daily and monthly reporting, and long-term statistics.
The AWS daily rainfall are routinely compared against the standard rain gauge. This ongoing comparison evaluates the coefficient that should be applied in the software to provide the highest possible accuracy of the AWS rainfall data. A record of current and past rainfall coefficients is provided in the station metadata.
Temperature
The AWS thermo-hygrograph is protected from direct solar radiation and other sources of radiated heat by a solar-powered fan aspirated radiation shield (FARS). When the ambient air temperature is quickly warming or cooling the thermo-hygrograph responds faster to temperature changes than the sensor in the Stevenson Screen. In these situations, spot temperature checks show the difference between the two sensor housings may exceed ±1.0° C due to the different response times. When the ambient air temperature is relatively steady, the temperature difference between the two sensor housings is typically within ±0.2° C.
The AWS maximum and minimum temperature data are routinely compared against a check thermometer in the Stevenson Screen for local accuracy, and also compared against the nearby BoM AWS network for areal consistency.
Mean Sea Level Pressure (MSLP)
The absolute pressure is the measured atmospheric pressure. The relative pressure is the atmospheric pressure corrected down to sea level, and is calculated by applying a height offset to the absolute pressure on the console and in the software. This corrected value, which equates to MSLP, is the most important element on a station weather plot.
The AWS MSLP data are routinely compared against the MSLP data from the BoM AWS at Laverton. This ongoing comparison evaluates the offset that should be applied to the console and the software to provide the highest possible accuracy of the AWS MSLP data. A record of current and past pressure offsets is provided in the station metadata.
Wind Speed and Direction
The AWS anemometer and wind vane are installed at a height of about 2 m instead of the standard height of 10 m. The wind data should therefore be used with caution.
Weather Display
A bug in the software occurs on the first day of the month, whereby the previous month does not change to the new month until 9:00 am. Coincidentally this is the start of the new meteorological day. All erroneous dates and computed values based on the erroneous dates are corrected in the data archive at the first opportunity after this time.
Performance Monitoring
To check for areal consistency, the daily maximum and minimum temperatures from the AWS are routinely compared against the BoM AWS at Laverton RAAF, Avalon Airport and Point Cook RAAF, whilst the daily rainfall from the standard rain gauge is compared against the BoM AWS at Laverton RAAF and the Melbourne Water rain gauge at Hoppers Crossing.
Top of page 