4. Optimize the SHEAR product configuration:
• Set the Product Range field to the maximum range of interest, and should roughly
correspond to the input bin spacing.
The 30 km (18.6 mi) range and 480 by 480 pixel product resolution in the example
match the 125 m (410 ft 1 in) sampling in the task.
In the example elevation angles of 0.5, 1.0, and 5.0, separate shear products can be
configured for each of the lowest 2 angles.
• It is recommended not to use any additional XY smoothing when the SHEAR
product is used for microburst detection because smoothing tends to diminish the
peak values that are of interest in the shear calculation.
The radial smoothing performed by the range filter, and the subsequent smoothing
performed in the WARN product are adequate.
The WARN product looks at the SHEAR products to determine whether to issue a
warning. In the example of 2 low-level scans (0.5º and 0.9º), each with its own SHEAR
product, the WARN product can be set to examine each. A threshold level of 8 m/s/km
is a good indicator of hazardous wind shear. A 1 km (0.6 mi) area threshold can be used
which corresponds to roughly 64 pixels for the case of 125 m (410 ft 1 in) bin spacing,
30 km (18.6 mi) range and 480 × 480 product resolution.
5. Optimize the Product Output menu to send the WARN product to a workstation so
that personnel can view the situation display.
a. Make the automatic output request so that the shear product is sent every time that
it is made.
b. Make sure a workstation is running the IRIS menus so that when windshear is
detected, the audible warning message and text can be viewed.
Warning messages are issued almost instantaneously when wind shear is detected.
Within a few seconds of receiving a warning message, the situation display is
presented. This depends on the speed of the communications link connecting your
display. However, because the situation display is an overlay product without a complex
picture, it can be transmitted eciently.
6. Tune the wind shear detection algorithms for each site.
This requires that qualified personnel perform the necessary optimization for your
particular meteorological and operational environment.
You must go through a thorough evaluation phase to test your system on your
particular site for your particular weather.
It is recommended that you make and record a RAW product every time a microburst is
detected and perform an analysis to determine if it was a real event or a false alarm.
To obtain a larger sample, you may want to expand the protected area to include all the
total area around the radar to the maximum range of detection required (typically 20 to
30 km (12.4 to 18.6 mi)) for air terminal applications. A qualified meteorologist should
assist with this evaluation.
IRIS Product and Display User Guide M211319EN-H
186 RESTRICTED
To Next Page
Loading...