India is set to deploy drones to gather atmospheric data that is currently collated by sending sensors through weather balloons released from at least 55 locations across the country twice every day.
The sensors embedded in a radiosonde, which is a telemetry instrument carried by a weather balloon, record atmospheric pressure, temperature, wind direction and speed as the hydrogen-filled weather balloon soars up to 12 km height and transmits data to the ground receiver through radio signals. However, weather balloons and radiosondes are unretrievable as they drift afar from weather stations that release them into the atmosphere.
“We are now exploring the possibility of using drones to gather this atmospheric data which is crucial for weather forecasting,” M Ravichandran, Secretary, Ministry of Earth Sciences, told PTI. Various studies have suggested that specialized drones equipped with sensors to gather weather data could be an efficient successor to the traditional weather balloons.
The India Meteorological Department (IMD) gathers weather data from 550 locations across the country through weather stations and uses radiosonde observations which are then fed into forecasting models to issue weather forecasts. The drones have a key advantage over weather balloons as they can be controlled and guided to fly at low as well as high altitudes.
The IMD plans to use drones to gather data from up to five km altitude and compare it with data gathered using traditional weather balloons. It has invited industry and academia to join the demonstration of the capability of drone technology for weather observations. “It is expected that drones should be capable, economically feasible, easily deployable and recoverable and should be technically comparable or superior to currently deployed radiosondes for upper air observations up to the boundary layer of upper air atmosphere,” the weather office said.
While the flight of a weather balloon usually lasts for up to two hours, the IMD expects to gather data using drones during a 40-minute flight. If successful, a key benefit would be reducing the wastage of radiosondes as the IMD loses more than 100 such instruments every day as weather balloons cannot be retrieved after their flight.