Assessing the Origin of Noise in the Precipitation Gauge Geonor T-200B

The Geonor T-200B is an all-weather precipitation gauge utilized by the Research Applications Laboratory (RAL) under the University Corporation for Atmospheric Research (UCAR) and the National Center for Atmospheric Research (NCAR). RAL has been dealing with a persistent issue of noise within the Geonor Devices during non-precipitation events. When there is not precipitation occurring, the data reading off the Geonor would be expected to be a constant value, as no precipitation is being collected. However, the device is producing unaccounted variation (noise) causing tremor like lines to appear in the data. The noise in the data is an issue for RAL because it makes it complicated to pinpoint the exact beginning and end of a precipitation event. Many airports use the Geonor sensors to predict unsafe flying conditions. Being able to pinpoint the beginning and ending weather patterns during storms would lead to more accurate and efficient airport scheduling. To isolate the source of the undesired noise two correlation experiments were run on the Geonor gauges. The experiments were conducted at the NCAR Marshal Field test site. The first test was to understand the effect of temperature change on the noise. The second test provided assess the effect of electrical interference on the noise in the device. The change in temperature correlated 63% to a change in frequency from the Geonor. The electrical interference test provided a reduction of variation in the frequency by two hertz. From the result of the study it can be stated that a change in temperature has a great effect on the noise from the Geonor and causes diurnal variation in the data. The electrical interference test showed promising results as a possible origin of the noise. Further experiments should be conducted to prove that adding an electrical shield reduces the noise within the device. Another source of noise to asses in further experiments would be the effect of temperature on the electrical panel that collects the data