Radio telescopes are used to observe our universe and to provide astronomers with detailed images and spectra. We use antenna technology to receive radio signals from the universe. There are different types of antennas: dishes such as used in the Westerbork Synthesis Radio Telescope (WSRT), and dipoles such as used in the Low Frequency Array (LOFAR). Many antennas are required to be able to do our science for the signals are very weak and because we need very sharp images. The WSRT has 14 dishes and LOFAR consists of over 100.000 small dipoles. Combining the signals from all antennas is called interferometry and requires electronic boards, photonic links, supercomputers and a lot of algorithms and software.
Radio astronomy delivers important breakthrough technology for our society. We collaborate intensively with industry to both maximise technology transfer to our partners leading to new jobs and increased competitive edge. Technology examples are Wifi, satellite navigation and big data solutions. Our science is extremely data intensive and the technologies that we deliver drive changes towards a smart society. LOFAR and Westerbork produce more data than is exchanged on the Amsterdam Internet Exchange at peak and the Square Kilometre Array (SKA) will generate more data than the global internet.
Sensitive and stable receivers
Since celestial radio waves are mostly very weak signals, large antennas and extremely sensitive and stable receivers are required. At the same time, these systems should be robust against the increasing man-made radio interference, caused by the boost in mobile broadband connectivity and navigation systems.
Electronic technology is used for transfer and processing of the received signals. This often requires innovative technologies as the data rates are very high. For example, the application of photonic technology in data transport and processing is attractive thanks to its excellent performance in broad bandwidths. Integrating technologies in the analog, digital, electronic, photonic, and mechanical domains is an important development towards our future telescopes as this will lead to more compact systems and will reduce power consumption and cost.
The mechanical properties of the equipment in the field is important as well. Design for robustness including thermal, humidity, and irradiance, ensures a long lifetime in harsh environmental conditions. Design for high wind loads and other extreme environmental conditions should ensure a high accuracy of the instrument under all circumstances.
A challenging factor in the design of large sensor systems is the high quality – low-cost/high-volume requirement. A close and good interaction with a variety of industries is crucial to prepare for mass production of components by industry.
The data from all antennas are combined in dedicated high performance supercomputers using the newest energy efficient accelerator technologies. Calibration algorithms are applied to correct for instrumental effects but also to correct ionospheric distortions. Imaging algorithms applied in pipelines produce high quality image cubes that allow astronomers to do their revolutionary science. The data is archived in open science clouds allowing reuse and increasing science output.