ZigBee Wireless Soil Moisture Sensor Design for Vineyard ...

Figure 20: Wind Machine
Helicopters: The main advantage of the helicopter is height and differential of
the inversion layer is not as critical as with a wind machine. Helicopters are
very effective when hovering at slower speeds around 5 to 10 mph and can
cover 40 to 50 acres (refer to Figure 21). In order to have maximum effect the
helicopter needs to hover overhead every 5 to 6 minutes before air
stratification reoccurs. The major set back is this method is very expensive,
and on an average it costs more $500 per hour plus standby fee [20].
Figure 21: Helicopter Hovering Down Hot Air
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