Testing off the Netherlands' longest bridge

Testing the Passive Reflectometry and Interferometry System (PARIS) concept off the 5022-m-long Zeeland bridge on the Dutch coast - the longest in the Netherlands - in July 2010. The two-sided antenna picks up satnav signals from above and their reflected counterparts from below. Correlating the two together turned out to give a measure of sea surface height to an accuracy of 5cm.