Chinese researchers and European guests behind the prototype millimetre-wave instrument for sounding through dense clouds and rain, seen left. Two millimetre-wave instruments have been combined together: China’s 54 GHz 21-antenna instrument is called the Geostationary Interferometic Microwave Sounder II, while ESA’s is the 183 GHz 24-antenna Geosounder II, designed for ESA by Omnisys Instruments in Sweden. ESA worked with the Chinese Academy of Sciences' National Space Science Center on the joint project.