Radio telescopes are some of the largest instruments in use in astronomy, but their (angular) resolution is actually somewhat poor. This can be improved upon by combining several radio telescopes, in a technique called radio interferometry. This creates a much larger virtual radio telescope, with its size (and resolution) determined by the longest distance between participating telescopes. For radio interferometry to work, the signals need to be captured against a stable reference clock at each station. If the reference clocks aren't stable enough, this will reduce the achievable sensitivity of the whole system.
White Rabbit is an open hardware system for the accurate transport of time and frequency signals over fiber. It was originally designed at CERN for controlling the Large Hadron Collider, but is now in use in many instruments in particle physics and astronomy.
We are researching the use of White Rabbit as a reference distribution system for radio astronomy. In particular, we have measured the phase noise of several types of White Rabbit links, and used this to quantify the suitability of White Rabbit for clock distribution in radio interferometry. We then created a mock radio interferometer using SDRs and GNU Radio, to verify these predictions. Finally, we demonstrate the use of White Rabbit and GNU Radio in radio interferometry during astronomical observations.
|Talk Length||30 Minutes|