Ten years back, when Hurricane Katrina was passing through the Gulf Coast, forecasters had a clear idea about the area the storm would hit and how powerful it would be. The thing they didn’t expect was the severe flood the hurricane caused after reaching southeast Louisiana.
Later, scientists came to know that during the 24 hours separating the last reconnaissance flights of Hurricane Hunters and the moment when the storm made landfall, the eyewall got knocked over by a high-level shear. The incident eventually caused the winds to expand horizontally and trigger a sharp increase in the water levels. Over 1,800 people lost their lives in the hurricane and the flood caused by it.
NASA is now getting ready to build a new array of a satellite called the Cyclone Global Navigation Satellite System (CYGNSS) with the aim of acquiring important storm data more frequently and thereby improving hurricane forecasts.
From the orbital perches situated at an angle of 35 degrees with the equator and 317 miles above our planet, the 8-member network will be picking up the storm signals from the Global Positioning System (GPS) satellite.
All the satellites in this system come equipped with advanced GPS receivers that possess the ability to measure changes in bounced signals resulting from scattering of the surface of the ocean. The data collected allows scientists to determine wind speed and a range of other key information.
The technology discussed above is referred to as Global Navigation Satellite System Reflectometry. We have already seen it being tested aboard aircrafts. However, CYGNSS, which will be launched sometime in 2016, will be marking the debut of this technology in space.
As a result of being equipped with 8 satellites, each as big as a suitcase, the technology will allow the system to carry out wind measurements once in every few hours. On the contrary, the polar-orbiting satellites of the present generation could do that only once in every few days.
Another notable quality of the GPS signals is that they are completely immune to heavy rains. For those who don’t know: heavy rains stop weather satellites of the current generation from measuring the speed of winds close to the center of the storm.