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. Our station metadata contains a record of the applied coefficients.
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.
Despite the different thermal characteristics of the two sensor housings, the reported maximum temperatures generally show good agreement. For minimum temperatures however, comparison results suggest there is localised nighttime heating responsible for the consistently warmer minimum temperatures in the Stevenson Screen than those measured by the thermo-hygrograph. Both AWS maximum and minimum temperatures generally compare favourably with stations in the nearby BoM AWS network, thereby showing good areal consistency. These results from our routine monitoring inspire confidence in the accuracy of the AWS maximum and minimum temperature data.
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, more commonly known as MSLP, is the key element of 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. Our station metadata contains a record of the applied offsets.
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.
Top of page 
Performance Monitoring
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 rainfall data are compared against the BoM AWS at Laverton RAAF and the Melbourne Water rainfall station on Skeleton Creek at Hoppers Crossing. The following table compares our daily data against the two closest sites at Laverton RAAF (Laverton) and Skeleton Creek (Hoppers).
