Technique Uses GPS Signals to Gauge Hurricane's Strength
University of Michigan engineering researchers are working on a global satellite project that would help predict the intensity of a hurricane while it is developing. In coordination with NASA, Michigan Engineering Professor Chris Ruf is working on the Cyclone Global Navigation Satellite System (CYGNSS), which will use GPS signals to see inside the storm - something that has never been available via satellite before.
Transcript
00:00:05 There has been a huge amount of improvement over the last twenty, thirty years because of satellites in our ability to forecast where hurricane's gonna go and there's been essentially no improvement whatsoever in our ability to forecast how strong it is gonna be when it gets there If you think back on the problems that happened when Katrina made landfall in New Orleans in 2006 the forecast for the track of that hurricane was very accurate They had it right on They knew exactly where it was gonna make landfall and when it was gonna make landfall But their forecast for how strong the storm was gonna be was way, way off
00:00:38 They forecasted a storm surge, which is how high the ocean comes up because of the wind when it makes land fall; I think it's about 10 or 12 feet But the actual surge is about three times as big and that's why there's a huge flood and that sort of mistake in forecasting is exactly what we're going after with this new mission We were awarded a contract from NASA for the satellite mission called the Cyclone Global Navigation Satellite System, for the summer and we are gonna be starting the work on it this fall It involves building eight small satellites and putting them up in orbit in the tropics to monitor hurricanes Traditionally, to measure what's going on in the middle of a hurricane
00:01:21 you can't use satellites because the strength of the hurricane is determined by what's going on in the middle of the hurricane; we can't see into the middle with traditional satellites So we, the research community, has developed a new technique that can see into the middle of hurricanes through the rain and it uses GPS signals and usually the GPS signal just goes straight to your cell phone and tells you where you are but the signals also bounce off of things and in particular they'll scatter off the ocean surface in a hurricane and what we're looking for, looking down from the satellite is this GPS signals that scatter off the ocean surface and come back up to our satellite
00:01:58 and by analyzing the details of how the signal gets distorted by the ocean you can figure out how strong the winds are So with this mission we're gonna be the first satellites up there that can penetrate through the rain and because of that we're going to be able to make fundamental improvements in how well we can forecast the strength of a hurricane and being able to do that it makes all the difference and, you know, your preparation: whether to evacuate or not, whether to open up the levees and let the water drain and all the sort of things you do in preparation
00:02:29 for a hurricane