Tides and waves measured by radar

An FMCW radar has been modified to measure the height of ocean waves and tides. Originally intended to measure hurricane waves to aid in offshore platform design, this system has the advantage of having no elements in the water. No wave staffs to lose. The radar beam of 4300 MHz frequency modulated over 70 MHz is reduced in beamwidth to by additional horns. This beam is reflected from the water surface and an average distance measured as a function of time. The system has been tested on Platform HOPE in the Santa Barbara Channel for eight months. In the absence of large waves, the radar system measured four foot waves and tides. The tide radar data were checked with USC & GS Rincon Island tide measurements. Since the wave or tide data are contained in the frequency of an audio signal, these data can be sent over a telephone line and remotely displayed. A system such as this using a magnetic tape recorder might be used on a number of offshore platforms for wave height monitoring.