2.1.4 Noncontact RADAR Sensors
A newer sensor technology for water level measurement available on the market is
noncontact RADAR sensors. These sensors are mounted above the water on a
bridge or other structures and have zero contact with the water. A microwave
pulse is transmitted towards the water, and the time for the pulse echo to return is
directly related to the distance from the sensor to the water surface.
Figure 4 shows a tide gauge RADAR-based water level sensor combined with a
data logger installed on NOAA (National Oceanic and Atmospheric Administration) Pier in Scituate, Massachusetts (USA) [3]. Recently, NOAA published an
updated version of the field installation and design analysis guide for microwave
water level sensors [4]. Figure 5 shows the RADAR-based water level sensor
system typical output. Water level measured values (blue) are plotted against the
predicted (green). The tide gauge logs data every 6 min and posts to a website every
15 min.
Fig. 3 Illustration of a typical shaft encoder installation. Source: Second author
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T. Younos and C.J. Heyer
A newer sensor technology for water level measurement available on the market is
noncontact RADAR sensors. These sensors are mounted above the water on a
bridge or other structures and have zero contact with the water. A microwave
pulse is transmitted towards the water, and the time for the pulse echo to return is
directly related to the distance from the sensor to the water surface.
Figure 4 shows a tide gauge RADAR-based water level sensor combined with a
data logger installed on NOAA (National Oceanic and Atmospheric Administration) Pier in Scituate, Massachusetts (USA) [3]. Recently, NOAA published an
updated version of the field installation and design analysis guide for microwave
water level sensors [4]. Figure 5 shows the RADAR-based water level sensor
system typical output. Water level measured values (blue) are plotted against the
predicted (green). The tide gauge logs data every 6 min and posts to a website every
15 min.
Fig. 3 Illustration of a typical shaft encoder installation. Source: Second author
178
T. Younos and C.J. Heyer