Abstract: An anti-fouling submersible liquid sensor (100) is provided according to the invention. The anti-fouling submersible liquid sensor (100) includes a measurement chamber (102) including one or more liquid measurement sensors (121) and at least one chamber aperture (104), at least one gate (107), a gate actuator (128) configured to selectively move the at least one gate (107) between open and closed positions with regard to the at least one chamber aperture (104), and a radiation source (124) configured to inactivate at least a portion of a liquid sample in the measurement chamber (102). The anti-fouling submersible liquid sensor (100) is configured to admit the liquid sample into the measurement chamber (102), perform one or more measurements on the liquid sample, substantially inactivate biological material within the liquid sample with radiation from the radiation source (124), and hold the inactivated liquid sample until a next sample time.

Abstract: A radar device for measuring the surface velocity of water moving in a horizontal plane in which the radar device is positioned above or below the horizontal plane. The radar device includes a tilt sensor, or accelerometer, to measure the angle of tilt of the radar device with respect to a target point located at a distance from the radar device. The accelerometer generates a signal representing the tilt angle. A processor in the radar device calculates the cosine correction factor that is applied to the measured velocity of the target point. This results in an automatically corrected measured velocity being displayed on the radar device.