To measure the two-dimensional wind direction and
velocity, a sensor unit with a diameter of 150 mm and a
height of 120 mm was produced using mono cast nylon
(MC nylon), which has excellent mechanical strength and
high abrasion resistance, for the plates for blocking vertical
winds and fixing the transmitter and receivers, as shown in
Fig. 3.
For the ultrasonic sensors, water-resistant sensors with
a resonant frequency of 40 kHz and a directivity angle of
90 were used. The transmitter was put at the center of
the top plate, and four receivers were placed in the xand
y-axis directions (two in each direction) within the
directivity range of the transmitter. The distance (L) between
the transmitter and receivers was set at 100 mm,
and the angle (u) between the movement path of the
ultrasonic signals and the wind was set at 60. The produced
sensor module is shown in Fig. 3.