The European Space Agency (ESA) announced that it was recently forced to change the frequencies used by some of its satellites in order to work around interference emitted from Earth-bound wireless communication installations, some of which are illegal.
At a recent briefing to London’s Royal Society dedicated to discussing the results of ESA satellites compiling data on climate change – charting, for example, rising sea levels and soil moisture – ESA Earth Observation Director Volker Liebig said that many terrestrial wireless communication systems fail to comply with regulations, resulting in signals that interfere with the ESA’s projects.
For example, some operators use their systems outdoors instead of indoors, violating the terms that their systems were approved under, making them a nuisance at best and a roadblock at worst, to the ESA and others. The ESA’s Soil Moisture and Ocean Salinity satellites, in particular, suffer from interference from terrestrial wireless communication systems.
In order to combat this interference, Liebig said that the ESA changed the frequency used by their radar-equipped Sentinel satellites, the first of which was launched in April.. However, the agency is not comfortable with these modifications, and does not wish to concede any further to terrestrial network operators.
“We have interference from illegal installations in this frequency band,” Liebig said.. “We are in another battle at the moment for the next ITU conference with the wireless land companies to protect the frequencies in C-band for our Sentinels- 1A and for the radar emitters with which we measure sea level rises. If we lose them, then we cannot do that anymore…so it’s an important battle.”
The ESA depends heavily on satellite information to chart environmental responses to climate change – an urgent topic in this era of global warming. The agency has gained important information about fast-dwindling polar ice sheets using its Cryosat satellite, and has compiled additional data to be analyzed further in the hopes of yielding future insights about climate change. Additionally, the ESA recently partnered with NASA on the IceBridge program, which analyzes information from 10 satellites to monitor the polar ice in further detail.
NASA’s Soil Moisture Active Passive satellite, scheduled to launch later this year, was constructed with these concerns about terrestrial interference in mind and is specifically designed to separate environmental signals from distracting signals emitted from terrestrial communication operations.
As terrestrial wireless network operators clamor for more bandwidth in frequencies previously reserved for the use of satellites only, the ESA publically pushes back, citing the importance of their cause and the damage that such Earth-bound operators cause. The fight is expected to heat up at the World Radiocommunications Conference, organized by the International Telecommunications Union, scheduled for 2015.
– Melanie Abeygunawardana
