AMES, Iowa – At the end of January, NASA placed a new satellite 426 miles over the Earth. It’s called the SMAP satellite, which is short for Soil Moisture Active Passive, and that’s exactly what it does: measures soil moisture.
Shenandoah native and Iowa State University Associate Professor of Agronomy Brian Hornbuckle says there are already other satellites with other types of cameras, however “this is the first one that has this type of microwave camera, and what’s special about this camera is it uses longer wavelengths of microwave radiation, and these longer wavelengths can see deeper into the soil. And they can also see through vegetation, and that’s really important. Previous satellites, vegetation would kind of hide the soil moisture and you think about how vegetation changes here in Iowa, it changes a lot.”
It’s important to be able to see through vegetation to take measurements from space, especially when USDA’s National Agricultural Statistics Service is releasing weekly crop progress reports during the growing season.
Currently NASS takes samples across the state to make an estimate of the soil moisture profile, and while Hornbuckle says NASS is doing the best it can, he wants to turn those estimates into measurements.
“It’s going to be a combination of using the satellite measurements but also computer models to kind of put all this information together to get the best estimate of how much water is stored in the soil in different parts of Iowa,” Hornbuckle explains. “So, yes, we have an estimate right now, but the quality of that estimate is probably not that good, and with this new information from satellites, we’re hoping to make those estimates better and better and better.”
The SMAP satellite can gather measurements at the township level, where previous satellites only took measurements on a county-wide scale. Part of Hornbuckle’s job is to validate data from the SMAP satellite, which he says will also contribute to a better understanding of weather and climate.
To hear more about the new SMAP satellite power by ISU and NASA, click the audio player above this story.
Image courtesy: NASA