News > NASA launches soil moisture-climate satellite
NASA’s Soil Moisture Active Passive (SMAP) observatory
On Saturday 31st January a rocket carrying a NASA satellite that will provide scientists with new tool for forecasting weather, track drought and monitor climate change launched from Southern California.
Once deployed, the satellite will aim two microwave-emitting instruments at the Earth’s surface to collect global data and calculate the moisture content of the top two inches of soil and water depth to about three feet. From an altitude of approximately 426 miles, the satellite will cover the whole of Earth’s surface in 2 to 3 days, at a spatial resolution of 5-6 miles.
A radiometer and radar will work simultaneously to detect subtle changes in a narrow spectrum of microwave radiation known as the L-band, as the microwaves scatter and reflect from the Earth’s surface.
“What we’re measuring is the dip in the energy coming back from Earth in this spectrum,” said Jared Entin, Nasa’s Washington-based project scientist for the Soil Moisture Active Passive (SMAP) mission. “The more the dip, the more water is blocking the signal.”
Up to now, the content of water in soil, plants and crops, has been a problematic factor in forecast and climate models. Scientists have mainly relied on a relatively sparse array of ground instruments. It is expected that once gathered, calibrated and verified, the data retrieved from the SMAP observatory will provide invaluable for forecasters and planners worldwide, helping to predict floods, droughts, famine, crop yields, weather and climate change.