Geometries for streamflow measurement using a UHF RiverSonde

Three geometries for a UHF streamflow radar system are examined: bistatic across the channel, monostatic on a bank, and monostatic in the center of the channel. The radar operates by analyzing the frequency spectrum of the received energy and determining the angles of arrival of energy at each frequency, so it is important to understand how the various geometries affect the width of the frequency spectrum and its angular distribution. We argue that placing the radar and antenna on one bank, with the antennas looking broadly across the river, generally produces the best results. The broad frequency spectrum allows many points to be analyzed, most of which have single-angle direction solutions (which generally are more robust than dual-angle solutions), and all the equipment can be placed at a single location.