In November 2009, the European Space Agency (ESA) launched its first-ever Soil Moisture and Ocean Salinity (SMOS) satellite to measure global soil-moisture levels. The satellite’s radiometer surveys 50 x 50 kilometers areas, using the detection of microwave emissions from land and water to construct global maps of moisture and ocean salinity. Scientists planned to use the data collected to better monitor and predict drought.
However, upon its activation SMOS’s radiometer began to encounter difficulties. Though the satellite’s signal frequencies fall in a protected range known as the L-band that is set aside solely for radio astronomy and Earth observation, transmissions from radar systems and TV and radio transmitters interrupted and corrupted large sections of data. In particular, images collected from SMOS show that China, India, eastern and southern Europe, some areas in the Middle East, and the majority of the northern United States are all interference hotspots. Though some national authorities were cooperative in turning off the radiation sources, others were unwilling to enforce the regulations.
To combat the remaining sources of interference, researchers for the ESA are developing intelligent data-processing algorithms to detect and eliminate interference as well as continuing to lay the groundwork to enforce regulation. NASA has also installed smart meters on its Soil Moisture Active Passive (SMAP) satellite, scheduled for launch at the end of 22014, to prevent the same problem.
