69.


The results are tabulated at table 3. For each example turbine height, the free space path loss to the turbine location is shown together with the calculated actual path loss to the turbine tip and to points 20m below and above the turbine tip height


Path loss Calculations Turbine Height


Equivalent Free Space path loss


204m 220m 244m


70.


(dB) -141 -141 -141


Table 3


Path loss to turbine tip


(dB) (dB)


-163.3 -163.5 -164.0


-258.7 -252.7 -247.0


Path loss Calculations


There is a significant difference in path loss between the turbine tip at the LoS height and a point 20m below the tip, suggesting anything 20m or more below the LoS height can be ignored from the calculation.


71.


Calculations indicating required RCS for detectability at LoS and LoS +20m are shown in the following diagrams.


(dB)


-158.0 -158.3 -159.0


Path loss to


turbine tip - 20m


Path loss to turbine tip +20m


Preliminary Environmental Information May 2014


East Anglia THREE Offshore Windfarm


Appendix 0 Example Page 18


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