Scientists Employ GPS-Equipped Cars to Measure Rainfall Across a Region

Rain can be variable across different parts of a region. It can fall more heavily in some locations while leaving others with little moisture. Now, scientists are using GPS-equipped moving cars as devices to measure rainfall. This could help meteorologists and researchers better understand weather patterns across a location.

"If moving cars could be used to measure rainfall the network density could be improved dramatically," said Uwe Haberlandt, one of the researchers, in a news release.

The news cars themselves are called RainCars. Yet in order to test them to see if they were a viable option, the researchers had to conduct a series of experiments. In one experiment, an individual in the care adjusted the wiper speed manually, depending on the windscreen visibility. This, in particular, showed the researchers that the front visibility was a good indicator for rainfall intensity. However, the measurements could depend on the person adjusting the wiper speed and so may not be reliable.

In another set of experiments, the researchers used a rain machine to test optical sensors installed in many modern cars to automate wipers. These optical sensors measured the rain in a more direct and continuous manner, which made them a better choice for rain sensors in cars.

That said, speed and wind can alter these measurements. In order to counteract speed, at least, the researchers studied the sensors in a controlled environment in order to correct for the effect of speed. Yet wind still remains an issue; however, higher accuracy isn't necessarily the goal.

"The value of using moving cars to measure rainfall is not about a higher accuracy of rainfall measurements but about a much higher number of measurement points," said Haberlandt in a news release.

The findings could be crucial for further developing these RainCars. More specifically, the cars could be employed in field experiments to measure rainfall in and around various locations. This, in turn, could provide scientists with more data about rainfall in the future.

The findings are published in the journal Hydrology and Earth System Sciences.