A 50-MHz spaced antenna/imaging Doppler interferometer system will be moved to a location near the Flatland radar in Illinois and to operate it there for a period of three years. The goal is to establish a mesoscale network near Urbana consisting of three radars in a triangular array with an average separation of approximately 20 km. The addition of the new facility to the two radars already operating near Urbana will allow measurements of a number of parameters important in the evolution of mesoscale and microscale meteorological systems, including horizontal and vertical velocities, vorticity, divergence, shears, deformation, and the vorticity equation tilting terms. The special capabilities of the spaced antenna/IDI system will also allow a study of the scattering mechanisms responsible for the echoes, the tilts of isentropic surfaces, and possibly the small-scale vorticity, divergence, and vorticity tilting terms on a spatial scale of 30-50 m, i.e., the scale characteristic of the separation of the antennas in the spaced antenna system. The addition of a third radar to the network increases the information that can be derived and the number of studies that can be carried out by more than a factor of ten over what can be achieved with either one or two radars.
