We describe the experimental framework that we have developed to study the use of synthetic aperture in GNSS receivers to estimate and mitigate multipath interference. By combining the signal received by a single moving antenna during different time instants along a known trajectory, it is possible to per-form spatial filtering on the received signal. Our framework is divided in two parts. First, we modified a software GNSS receiver to implement beamforming and direction of arrival (DoA) algorithms, which have been adapted to work with synthetic aperture, instead of with a fixed antenna array. Second, we built a rotating arm supporting an antenna in order to implement circular trajectories of 0.5 to 1 m radius, and adjustable rotating speeds of up to 1.5 rev/s. Finally, we present an analysis of the performance of the algorithms implemented using real data obtained with our rotating antenna.