NASA’s SMAP Satellite – Mapping Global Soil Moisture

NASA are set to launch the Soil Moisture Active Passive (SMAP) satellite on 29 January 2015.

As the name suggests, the satellite is equipped to help predict of floods and droughts by measuring soil moisture. As it orbits, SMAP will take an inventory of the earth’s soil, giving us detailed data to help better predict future floods and the severity of flood events.

NASA’s SMAP project manager, Kent Kellogg said:

“Soils are like sponges, and they can hold a certain amount of water. If we know the amount of water in the soils, and we know that there is a big rainstorm coming, and that the soils are near saturation, then we can predict that area might be at risk for flooding.”

A better understanding of soil moisture will also help scientists better analyse droughts, crop productivity and wildlife risks.

SMAP Satellte
SMAP satellite. Image: NASA

According to NASA:

SMAP will produce global maps of soil moisture, which will help improve our understanding of Earth’s water and carbon cycles and our ability to manage water resources.


Image: NASA
Image: NASA

Global Near-Real-Time Monitoring of Soil Moisture

The SMAP observatory will fly at an altitude of 426 miles (685 kilometers), completing one near-polar Earth orbit every 98.5 minutes. SMAP’s 6 metre antenna will allow the 944 kg satellite to collect data across a 1,000 km (621 miles) swath of the earth as it passes above. NASA predict that SMAP will be able to update moisture levels for the entire world every two to three days.

Soil moisture map. Image: NASA
Soil moisture map. Image: NASA

The mission began in 2007 and cost $916 million. The SMAP observatory mission is expected to last 3 years from launch date.

About the mission, NASA say:

The mission will advance our ability to monitor droughts and predict floods and mitigate their related impacts on people’s lives. It will allow the monitoring of regional deficits in soil moisture and provide critical inputs into drought monitoring and early warning systems used by policymakers.

The mission’s high-resolution observations of soil moisture will improve flood warnings by providing information on ground saturation conditions before rainstorms. Hydrologists will be able to model water flow down to the scale of individual river basins.