An A Priori Approach to Quality-Control Tipping Bucket Rain Gauge Data

It is widely known that tipping bucket rain gauges are prone to data quality issues as a result of clogs and other environmental phenomena. In most cases, these gauge malfunctions are only realized after precipitation has begun. While many techniques exist to quality control tipping bucket rain gauge data after a precipitation event, very little work has been done to determine gauge fitness prior to a precipitation event.

A novel approach has been developed to allow a weather station or weather network operator to determine the fitness of a remote tipping bucket rain gauge prior to a precipitation event. The method uses a pump apparatus to direct water from an underground tank into the funnel of the tipping bucket rain gauge. The pump supplies a known volume of water each time it is activated. If the volume measured by the tipping bucket rain gauge is not within a certain tolerance of the expected volume, all future data for the tipping bucket rain gauge is flagged until the cause of the gauge's failure has been determined. The test can be conducted remotely using two-way, cellular communications and activated using a datalogger with a microcontroller capability. Data from the tipping bucket rain gauge are also flagged in real-time to prevent erroneous data from being accepted by the system.

Using this method, malfunctioning tipping bucket rain gauge data can be flagged as suspect before the precipitation event even begins, and in some cases, allow technical staff to be deployed the field to perform a repair prior to the onset of precipitation, thus preventing the precipitation event from being missed. While this approach may not be applicable to every rain gauge network in operation, there are some basic components that could be employed in most situations.