NASA is set to launch a new satellite with the capacity to measure soil moisture on a global scale. Once operational, data from the Soil Moisture Active Passive (SMAP) satellite could be used to better inform farmers in agricultural decision making, providing unprecedented levels of detail on moisture trends with an efficiency and speed unattainable using current technology.
The methods of observation offered by the SMAP satellite, due to launch in November this year atop a Delta 2 rocket, will represent a significant leap forward in the field of soil moisture mapping. Previous satellite-based missions could not achieve the soil penetration or resolution boasted by the SMAP satellite.
Another form of soil observation used for moisture measurement prior to the launch of the SMAP system is to take spot measurements, however these are inherently unreliable, making it very difficult to gain an accurate reading over a large area. SMAP on the other hand carries out the same task on a global scale, mapping the entire planet once every two to three days.
The satellite will operate at a height of 227 miles (365 km) above the Earth in a near-polar sun-synchronous orbit, using its L-band radar and L-band radiometer to scan the top 2 inches (5 cm) of our planet's soil. SMAP will have the ability to capture moisture data with a resolution of roughly 31 miles (50 km), so whilst the satellite will not be able to provide farmers with field-to-field statistics, SMAP will still allow for the most comprehensive and detailed moisture map to date.
"If farmers of rain-fed crops know soil moisture, they can schedule their planting to maximize crop yield," stated Narendra Das, water and carbon cycle scientist on SMAP’s science team at NASA. "SMAP can assist in predicting how dramatic drought will be, and then its data can help farmers plan their recovery from drought."
It is hoped that information gathered by the satellite during its operational period could be used by the agency to better understand the processes that connect our planet's water, energy and carbon cycles, hopefully allowing us to create more accurate weather and climate models.