Manual – Starflow Ultrasonic Doppler Instrument
Model 6526
Unidata Manual - 6526 Starflow User Manual Issue 17 01 2020.docx
Page 52
12.2.3
Measuring Unexpected Velocities
In some cases signals are from the wrong targets. A waving weed, aquatic animals, a strong
stationary reflector in the bed, slow moving saltation targets or ripples on the surface can all
produce Doppler shifts that are not directly related to the water velocity.
The “field of view” of the Starflow can extend for at least 1m along the beam in clean water and
reduces as the sediment load of the stream increases.
The beam can reflect from the surface underside and can detect different velocities to those
expected. This results in a distorted peak, or a double or multiple peak in some situations, the
composite of all velocities seen along the path. Such sites may not be suitable for the Starflow as
the flow is not laminar.
