6
Location of Radar Installation
1.6.
1) Confirm the observed region in relation the topography features
In this example the radar must cover an altitude of 1500 meters maximum and a 70km distance
radius within the rainfall forecast area. Therefore there should not be any structures or objects
higher than radar around the installation point.
2) When installing antenna on building rooftop or a tall tower in urban area
When mount the radar on the stand or tower, it must be higher than any surrounding
obstruction (building, structure) for proper radar operation. The tower must be designed
strong enough to withstand heavy storms, winds and severe weather conditions.
Also remind that a crane or aerial work platform vehicle might be necessary to mount the
radar and install the tower. It is important to consider any additional space required for crane
operation during installation or repair.
3) Lightning protection and grounding considerations
Provide a lightning rod near or around the radar area to improve lightning protection
performance based on JIS A 4201, JIS Z 9290 and IEC 62305.
The protection systems should include surge protectors/absorbers.
The grounding system will typically consist of an underground grid, radials, or rods which
provide a ground resistance of not more than 1 ohm. It should have a connection point at the
base of the tower. Refer to APPENDIX A for more detail.
P
ower
P
ower
Range Side Lobe
Suppression
Ratio
Figure 1.7: Actual Condition
Observe area
NOT GOOD
GOOD
Side view
Top view
2
.
7 deg
GOOD
NOT GOOD
-3deg
0m
0.62m
m
12m
50m
-2m
0m
Main lobe threshold: -20dB
0m
Main beam
Return produces ground clutter
Main lobe
Figure 1.8: Ideal Condition
Figure 1.9: Distance of main lobe
