A new study recommends using GPS as a cheaper alternative to effectively measure a storm’s wind speed.
A research team from the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) had observed that GPS satellites are continuously transmitting radio waves or signals toward the Earth information which report each satellite’s position during the time of the transmission. They noticed that when a GPS signal hits a body of water, 60 percent of the radio waves bounce back to the sky. However, when the wind speed is so fast, the radio waves are scattered in different directions.
The disruption in the radio waves will be used to measure the wind speed of the storm. The scientists used the GPS receiver chips found in smartphones to collect data while on board the Hurricane Hunters-- a storm hunting aircraft. The computer where they have sent the data made an evaluation of the GPS signals transmitted by the satellites to the sea and the signals that bounced back. They used a certain formula to calculate the wind speed.
The scientists believe that this method is a lot cheaper than their current method which uses a device called dropsonde that they attach to parachutes and drop from airplanes along with other measuring instruments. The total cost amounts to $750.
They admitted that the dropsonde method is still 10 times more accurate than the GPS method but because of its cost, the meteorologists had to limit their wind speed recording. The GPS method may be done more often which can provide a real-time estimate of the wind speed of a storm. One problem that they encountered though with the GPS method is that it will only work if there are large bodies of water which the eye of the storm doesn’t have.
The method of measuring storm wind speed using the GPS will be called the Cyclone Global Navigation Satellite System (CYGNSS).
The study was published in Radio Science.
