SINGAPORE – Every time it rains, mobile phone signals are affected. Most users will not be able to tell the difference, although sensitive instruments can.
Now, research institute Hydroinformatics Institute (H2i) and telco StarHub will be embarking on a pilot that aims to improve rainfall measure in Singapore, by analysing these changes in mobile phone signals during rain.
The pilot will take place in the south-west of Singapore in the second quarter of this year, said H2i and StarHub in a statement last week.
The aim is to improve rainfall readings in Singapore, which are critical for water resource management, early flood warnings and weather predictions, they added.
Currently, national water agency PUB uses tools such as rain gauges and X-band radars to measure rainfall.
Rain gauges are essentially marked tubes that collect rain, giving meteorologists an idea of how much rain was collected at a point in that rainfall event. X-band radars measure rainfall by sending pulses of electromagnetic radiation into the atmosphere and listening for return signals scattered back by rain droplets.
But there are limitations to the data collected through these methods.
Dr Munsung Keem, radar specialist from H2i, said: “Rain gauges can only measure rainfall data at a given point, making data collected sporadic and distributed sparsely around Singapore.
“Although radar tools can collect data across wide areas spanning 30km to 50km, radar waves are sometimes blocked by tall buildings like skyscrapers, making data collection incomplete.”
In the tropics, where rainfall varies greatly over space and time, rainfall episodes can often be challenging to quantify and forecast, H2i and StarHub said.
“Having a greater variety and density of data sources can make modelling more accurate, and predictions more precise,” they added in the statement.
When it rains, falling water droplets sometimes interferes with mobile signals being sent island wide.
These periodic interferences cause miniscule variations in mobile signal strength, which are usually automatically compensated for by StarHub’s mobile base station and are recorded as they occur.