Less than four months after lift-off, testing on NASA's Soil Moisture Active Passive (SMAP) observatory is complete, and science operations have begun. The data recorded by the mission, which will give rise to more accurate weather forecasting, will now be subject to a year of validation against existing measurements.
The goal of the SMAP mission is to provide up-to-date global soil moisture maps, measuring a 620-mile-wide (1,000-km) swathe of the ground below as it flies at an altitude of 426 miles (685 km) from pole to pole. It's designed to detect whether soil is frozen or thawed, and will help researchers to better understand the planet's water, carbon and energy cycles. In the long run, it should lead to improved weather predictions and monitoring of hazards such as flooding.
The mission launched on January 31, and the satellite's 20-ft (6-m) antenna was unfurled back in February. The team then worked to spin-up the antenna to its full 14.6 revolutions per minute, before powering on the radio and radiometer instruments at the end of March, and testing their performance and accuracy.
The first global view from SMAP was captured between the May 4 and 11 at a spatial resolution of 5.6 miles (9 km). It reveals moist soil conditions in the US Midwest, Europe and Asia, and dry soil in the Southwestern US, and Australia and elsewhere. The full image can be seen above.
Over the next 12 months, the SMAP data will be validated via comparisons with existing ground-based measurements, aircraft-mounted solutions and readings from other satellites. Looking past that, the mission is set to have a significant impact on our understanding of the planet's climate.
"SMAP data will eventually reveal how soil moisture conditions are changing over time in response to climate and how this impacts regional water availability," says SMAP science team leader Dara Entekhabi. "SMAP data will be combined with data from other missions like NASA's Global Precipitation Measurement, Aquarius and Gravity Recovery and Climate Experiment to reveal deeper insights into how the water cycle is evolving at global and regional scales."