Ground-based interferometry has several advantages over satellite interferometry. Using ground-based radar alleviates the problems associated with long revisit times, atmospheric effects, and the lack of densely-sampled data. The USF Geodesy Laboratory is in the process of obtaining a GAMMA Portable Radar Interferometer (GPRI). The GPRI is a real-aperture radar that operates at a frequency of 17.2 GHz (Ku-band) and allows for millimeter precision. The device consists of one transmitting antenna and two receiving antennas. Since the receiving antennas have a small separation distance between them, the signals received at each one can be combined to generate an interferogram. The GPRI is also portable and easy to set up and is able to collect a number of images in an hour (as opposed to several days or longer for InSAR), opening up new, frequent, and precise measurement possibilities not previously possible with satellite interferometry.
