MOBILE PHONE MAST SIGNALS EXTREMELY USEFUL TO FORECAST RAIN

The global use of mobile phone technology in forecasting rains and floods should be an eye opener for the Pakistani authorities.

By SHABBIR H. KAZMI
Aug 28 - Sep 03, 2006

During the recent rains people were stranded on roads and malfunctioning of PTCL landlines left most of the people with no option but to rely on mobile telephones. Though, there could be totally opposite experience of people but the fact is mobile phones have emerged as a major blessing. Some of the subscribers may have found getting access to the desired numbers difficult or experienced interruption in service there could be many rationalizations. However, mobile phones provided a bridge to the 'split' families.

Many of the leading global mobile telephony companies are not only operating in Pakistan but also making huge investment to attain technological edge. This has not only made mobile phone affordable for common man but also made it a necessity of life. On top of every thing the substantial decline in tariff and cost of set enabled people to acquire connection from more than one mobile telephone companies. Though, it may look a bit expensive but at time cost becomes of no consequence.

One may write hundred of pages about the benefits of mobile telephony. However, one aspect needs immediate attention of authorities responsible for forecasting and informing people about rains in Pakistan. One of the reasons for loss of human life during rains and floods in any area is failure in informing the masses abut the forthcoming rains or floods in time. While the ongoing research in many areas is certainly helping the authorities, the global use of mobile phone technology in forecasting rains and floods should be an eye opener for the Pakistani authorities. The two examples cited may raise eyebrows of critics but just cannot be ignored. Pakistani authorities may not like seeking help from Israel but can certainly approach the Natural Environment Research Council of the UK.

According to a report released by the BBC News, signals from mobile phone masts have been used to measure rainfall patterns in Israel. A team from the University of Tel Aviv analyzed information routinely collected by mobile phone networks to make their estimates. The researchers say that their technique is more accurate than current methods used by meteorological services.

Similar work has been done by scientists in the UK.

Researchers funded by the Natural Environment Research Council (NERC) set up a mock mobile network near Bolton in the north of England to show how these signals can measure rainfall. Further demonstrations were done in Germany and Italy as part of an EU project. Researchers from all countries believe the technique is promising in issuing flood warnings.

Although both sets of work are similar, the team from Tel Aviv University says their work differs because they are using real data from an existing mobile network. However, the fact is that both the methods exploit the fact that the strength of electromagnetic signals is weakened by certain types of weather and particularly rain. The effect was commonly seen in the days before cable television. Whenever there was a storm outside, viewers had a bad picture on their TV. Professor Hagit Messer-Yaron of the University of Tel Aviv, said, "I see our innovation as taking a network that is designed for one purpose and using it for another. To make the measurements the researchers analyzed data collected automatically at mobile base stations around Tel Aviv, Haifa and Jerusalem.

The data is a by-product of mobile network operators' need to monitor signal strength. If bad weather causes a signal to drop, an automatic system analyzing the data boosts the signal to make sure that people can still use their mobile phones. The amount of reduction in signal strength gave the researchers an indication of how much rain had fallen.

When they compared their estimates with measurements from traditional monitoring methods, such as radar and rain gauges, they discovered that the readings from all three closely matched. But overall the new technique seems to give more precise measurements than radar and was able to monitor a greater area.

Researchers in the UK have also shown that a similar method works using signals from global positioning satellites. Scientists at the Institute of Engineering Surveying and Space Geodesy (IESSG) - part of the University of Nottingham - have demonstrated that the fluctuations in these signals are a good measure of atmospheric humidity.

However, the team from Tel Aviv University believes one of the advantages of its method is that it can measure rainfall at the surface and the technique therefore gives an accurate picture of the weather on the ground.

Currently the meteorological services use rain gauges, which are expensive and the use is not widespread. These are also not considered accurate at measuring low rates of rainfall and in places like the UK as these are prone to freezing up. But the information necessary for this novel approach is effectively free, continuous and comes from a dense network of masts that already span almost the entire globe.

Professor Yaron believes the technique could act as a cheap and valuable complement to existing systems for meteorological services. The challenge is to get mobile network operators to routinely provide the data they collect for a national monitoring system. The next step for the team is to make use of the mobile phone users themselves - to start analyzing their signal data to see if even greater accuracies can be achieved. To do this, Professor Messer-Yaron must work out how to differentiate between changes in signal strength that are due to mobile phone users moving around and those that are due to weather conditions.