Water quality in a major port monitored by HF ocean surface radar

The HF coastal ocean surface radar system developed at James Cook University was used as part of the Port Phillip Bay Environmental Study to produce current maps over a complex system of channels and sandbanks at the mouth of the large bay which is landlocked except for a narrow channel to the sea (Prytz and Heron, 1994). The radar data provide clear advice that tidal flushing of the bay is severely restricted by the geomorphological structure of the entrance to the bay. It is shown that Port Phillip Bay is replenished by long period variations in the water level caused by atmospheric pressure fluctuations and water run-off from the immediate water catchment area. The COSRAD HF ocean surface radar uses a single linear array of antennas for transmitting and receiving. This provides a narrow beam of about 7.5 degrees which can be electronically steered in azimuth to cover about 900 square kilometres of ocean surface. Two separate stations are required with crossed beams to produce good quality surface current maps