Frodsham Wind Farm Impact on Hawarden PSR · 2011-11-02 · 2.4 Pd Calculation from Hawarden Radar to Frodsham Wind Farm – VPD Data 2.4.1 The generic 10cm wavelength radar VPD data

Frodsham Wind Farm

Impact on Hawarden PSR

COMMERCIAL IN CONFIDENCE

FRODSHAM WIND FARM IMPACT ON HAWARDEN PSR

CL-4762-RPT-001 Issue 1.0 CYRRUS LIMITED 1 of 42

Document Information

Document title Frodsham Wind Farm Impact on Hawarden PSR

Author Sam Shuttlewood and Martyn Wills, Cyrrus Limited

Produced by Cyrrus Ltd

Cyrrus House

Concept Court

Allendale Road

Thirsk

North Yorkshire

YO7 3NY

Tel: +44 (0)1845 522585

Fax: +44 (0)870 762 2325

e-mail: [email protected]

URL: www.cyrrus.co.uk

Produced for Hawarden Aerodrome

Cyrrus Limited contact Martyn Wills

Tel: +44 (0) 1845 522585

Fax: +44 (0) 870 762 2325

Email: [email protected]

Produced under contract 1100067303

Version Issue 1

Copy Number Copy 1 of 1

Date of release 22nd September 2011

Document reference CL-4762-RPT-001

CHANGE HISTORY RECORD

New Issue Date Details

Draft A 13/09/2011 Internal Review

Draft B 15/09/2011 Client review

Issue 1.0 22/09/2011 Initial Issue

http://www.cyrrus.co.uk/




CONTROLLED COPY DISTRIBUTION LIST

Copy Number Ownership

1. Airbus Hawarden

2. Airbus Hawarden

3. Cyrrus Ltd

Prepared by...................................................

Sam Shuttlewood

Project Engineer

Cyrrus Limited

Prepared by...................................................

Martyn Wills MRAeS

Director

Cyrrus Limited

Authorised By ...............................................

BJR Hawkins MBA

Director

Cyrrus Limited

© 2011 COPYRIGHT STATEMENT

This document and the information contained therein is the property of Cyrrus Limited. It must not be reproduced in whole or partor otherwise disclosed to parties outside of Cyrrus Limited without prior written consent.




Executive Summary

Cyrrus Ltd has carried out an assessment of the impact of the development of FrodshamWind Farm on the operations at Airbus Chester Hawarden Airport.

Having carried out a detailed technical investigation, the following impacts have beenidentified:

All of the wind turbines at Frodsham will be detected by the current and new radarsat Chester Hawarden Airport.

The turbines will appear on the radar displays as an area of clutter within the RadarVectoring Area immediately adjacent to the final approach track to runway 22.

Radar clutter in the location of Frodsham compromises the ability of Hawarden Airtraffic Control to offer a radar service to aircraft arriving to Runway 22 (Thepredominant runway).

Having identified that the radar performance will be compromised, suitable mitigationoptions have been explored and the following conclusions have been reached:

Operational mitigation is not a viable option due to the physical location of Frodshamrelative to Hawarden.

Optimisation of the radar at Hawarden to remove or supress the turbine clutter is notpossible without compromising the ability to detect aircraft.

The only mature technology currently demonstrated to mitigate the clutter problem isinfill from an unaffected radar source.

Preliminary investigation indicates that there are potential existing radar sources thatcould provide suitable radar data infill in the area of Frodsham which may meet theoperational requirement. Alternatively, a new radar sensor could be introduced tofulfil this function.

Frodsham will also have a significant effect on the radar at Liverpool John Lennon Airport,which it is assumed will also require a similar technical solution. It is very likely that if an infillsolution is implemented, that the same source would satisfy the requirements of bothChester Hawarden and Liverpool John Lennon Airports.




Contents

1 Introduction ............................................................................................................ 5

1.1 Overview .................................................................................................................. 5

2 Methodology........................................................................................................... 6

2.2 Line of Sight from Hawarden to Frodsham Turbines................................................. 6

2.3 Pd calculations from CEG PSR Radars to Frodsham Wind Farm............................. 6

2.4 Pd Calculation from Hawarden Radar to Frodsham Wind Farm – VPD Data............ 7

2.5 Pd Calculation from CEG to Frodsham Wind Farm – Path Loss Data ...................... 8

2.6 Pd Calculation – Two-way Path Loss Calculations ................................................... 8

3 Findings ................................................................................................................ 10

4 Potential Mitigation .............................................................................................. 19

4.2 Operational Mitigation............................................................................................. 19

4.3 Technical Mitigation................................................................................................ 20

5 Conclusions.......................................................................................................... 24

5.1 Summary................................................................................................................ 24

A Abbreviations and acronyms............................................................................... 25

B Turbine and PSR Data.......................................................................................... 26

C LOS Results from Hawarden Airport................................................................... 27

D Pd Calculations to Frodsham .............................................................................. 41

Table of Figures

Figure 1: Position of CEG current and new PSR in relation to Wind Turbines......................................5

Figure 2: Typical PSR VPD from CAP764 Appendix 7 (2006) ..............................................................7

Figure 3: Graph of Elevation v Gain from data at Figure 2....................................................................8

Figure 4: LoS from the current CEG AR15 PSR to 125m agl..............................................................10

Figure 5: LoS from new CEG EA5025 PSR to 125m agl.....................................................................11

Figure 6: LoS Profile from the current CEG AR15 PSR to the Frodsham Wind Farm Turbine T1......11

Figure 7: Total Path Loss to Blade Tip (125m) ....................................................................................13

Figure 8: Total Path Loss to Blade Mid-point (102.5m) .......................................................................14

Figure 9: Total Path Loss to Nacelle (80m) .........................................................................................15

Figure 10: Example of Radar 2-way path loss calculation...................................................................16

Figure 11: Profile from CEG AR15 PSR to Frodsham Turbine Tip T1 – Electrical Tilt Angle .............17

Figure 12: Graph of Elevation Angle v Relative Gain for 0° Antenna Tilt ............................................17

Figure 13: Position of Frodsham relative to CEG runway 22 arrivals..................................................19

Figure 14: LoS from St Annes Radar to 125m agl...............................................................................21

Figure 15: LoS from Warton Radar to 125m agl..................................................................................22



CL-4762-RPT-001 Issue 1.0

1 Introduction

1.1 Overview

1.1.1 Hawarden Chester Airport (CEG) has commissioned Cyrrus Ltd to complete anaviation assessment to establish the impact of Frodsham Wind Farm on thecurrent and planned Primary Surveillance Radars at CEG.

1.1.2 The proposed wind farm consists of 20 turbines, of height 125m AGL, located intwo separate clusters on an area of land used to deposit dredging from theManchester Ship Canal.

1.1.3 Hawarden Airport is located approximately 16km south-west of the proposeddevelopment. A Plessey AR15 Primary Surveillance Radar (PSR) is located atthe Airport and a new EASAT EA5025 PSR is in the process of being installedand commissioned nearby on the airfield. The location of CEG in relation to theFrodsham Wind Farm development is shown in Figure 1.

Ordnance Survey © Crow

Figure 1: Position

Wind Turbines

CEG PSR (old

CYRRUS LIMITED

n copyright, All rights reserved. 2011 Licence number 100050170. Reproduced with

of CEG current and new PSR in relation to

and new)

Frodsham

5 of 42

the permission of NATS

Wind Turbines




2 Methodology

2.1 Evaluation Tools Used

2.1.1 The following tools are used during the evaluation:

ATDI Hertz Mapper v3.33; configuration:

Frodsham.svr

Frodsham.geo

Frodsham.img

Frodsham_Hawarden.lin

Digital Terrain Model constructed Shuttle Radar Topography Mission(SRTM) Data – 90m horizontal resolution;

Microsoft Excel;

2.2 Line of Sight from Hawarden to Frodsham Turbines

2.2.1 The software package used to determine the Line of Sight (LoS) between theradar and the wind turbines is an industry package – ATDI HerTZ Mapper. Itshould be noted that Cyrrus Ltd assess radar LoS using a digital terrain modelthat uses SRTM terrain elevation data.

2.2.2 The turbines that comprise Frodsham Wind Farm have been modelled to have amaximum blade tip height of 125m above ground level (agl), assuming an 80mtower. Data on the PSRs have been provided by the engineering department atCEG.

2.2.3 The location of the radar and turbines are introduced into a HerTZ Mappersoftware model with their corresponding heights to create an area networkrepresentation. The elevation at these points is given by the terrain mapping filewithin HerTZ Mapper.

2.3 Pd calculations from CEG PSR Radars to Frodsham Wind Farm

2.3.1 The gain of a radar antenna in the vertical axis is not uniform with elevation angle.The beam is a complex shape (Cosec2) to minimise ground returns by having alow gain at elevations close to the horizontal but have a high gain at elevationsjust a few degrees above the horizon.

2.3.2 The maximum gain of the antenna usually occurs at an elevation angle of around1.5° above the horizontal. Gain falls off rapidly at lower elevation angles. Inaddition, airport radars frequently have an upward tilt on the antenna to minimisethe illumination of ground clutter in the vicinity of an airport. These specificoptimisation settings are required to be included in Probability of Detection (Pd)studies.




Figure 2: Typical PSR VPD from CAP764 Appendix 7 (2006)

2.3.3 A generic antenna Vertical polar Diagram (VPD) was used (Figure 2), asapplicable to a 10cm, terminal Air Traffic Control PSR utilising a Cosec2 antennabeam pattern.

2.4 Pd Calculation from Hawarden Radar to Frodsham Wind Farm – VPD Data

2.4.1 The generic 10cm wavelength radar VPD data from Figure 2 is entered into anMS Excel spreadsheet and plotted as a smoothed line of elevation v gain. Fromthis graph, intermediate values of antenna gain can be determined and are shownin Figure 3.




Figure 3: Graph of Elevation v Gain from data at Figure 2

2.4.2 Using HerTZ Mapper software it is possible to derive the electronic elevationangle from the radars to the turbine tips. Any physical antenna tilt must also betaken into consideration and integrated into the Pd analysis.

2.5 Pd Calculation from CEG to Frodsham Wind Farm – Path Loss Data

2.5.1 Having built the 3-D model with the refined data, radio propagation profile checkswere made to the wind farm. The static parts of the turbine (tower structure) wereignored from the Pd calculation as these will be rejected by the radar MovingTarget Indicator filter.

2.5.2 Three parts of the turbine blade were considered: the hub; the blade tip; and apoint midway along the turbine blade. In accordance with the guidance in CAP764 (July 2006 version) Appendix 7, each part of the turbine blade was assignedas RCS of 10m2 and path loss calculations were made to each of the turbinepositions. The received signal at the radar from each component part of theturbine was then summed to determine the received signal level.

2.5.3 Radio profile checks, and the subsequent path loss calculations, were conductedand radar signal returns were calculated to the standard 3 points at each positionas described at paragraph 2.5.2.

2.6 Pd Calculation – Two-way Path Loss Calculations

2.6.1 Radar signal returns are calculated using an Excel spreadsheet to the threepoints on the turbine described in paragraph 2.5.2. The 2-way path losscalculation is carried out for each turbine component as follows:




Tx Power dBm

+ Antenna Gain dB

- Path Loss dB

+ RCS Gain dB

- Path Loss dB

+ Antenna Gain dB

= Received Signal dBm

2.6.2 The received signals from the three components are then summed and comparedwith the radar receiver Minimum Detectable Signal level.

2.6.3 Where known, specific operating parameters of the CEG radars were used for thestudy; where this was not available, generic parameters that came from the sametype of equipment in use at other locations were utilised.



CL-4762-RPT-0

3 Findings

3.1 PSR Los Assessment

3.1.1 A LoS study was undertaken from the current AR15 and new EA5025 radar atCEG to Frodsham Wind Farm.

3.1.2 Figures 4 and 5 depict those areas where the current and new radars areexpected to detect an object with a height up to 125m agl. The Cyan colouringshows those areas where the radar would have direct LoS to a turbine of thespecified height; conversely, the clear areas show where the PSR would not havedirect LoS to such an obstacle.

Wind Farm

CEG PSR –

01 Issue 1.0 CYRRUS LIMITED

Ordnance Survey © Crown copyright, All rights reserved. 2011 Licence number 100050170. Reproduced wit

Figure 4: LoS from the current CEG AR15 PSR to 1

current AR15

Frodsham

10 of 42

h the permission of NATS

25m agl



CL-4762-RPT-001 Issue 1.0 CY

Ordnance Survey © Crown copyright, All rights reserved. 2011 Licence number 100050170. Reproduced with the permission of NATS

Figure 5: LoS from new CEG EA5025 PSR to 125m agl

3.1.3 Figures 4 and 5 indicate that both CEG radars should have LoS to the proposed125m (agl) turbines at Frodsham.

3.1.4 LoS profiles from both radars to each individual wind turbine were conducted. AllLoS profiles for both radars can be found in Annex C.

Figure 6: LoS Profile fromW

Hawarden PSR

new EA5025

Wind Farm

Terrain

RRUS LIMITED

the currentind Farm T

LOS

CEG AR15 PSR turbine T1

Turbine

CEG PSR –

o

Frodsham

11 of 42

the Frodsham




3.1.5 In Figure 6 above, the AR15 PSR is shown at the left hand edge of the graphicand the Frodsham Wind Farm T1 Turbine is shown at the far right hand side. Theblue line represents the LoS profile to the turbine tip (125m agl). The twoellipsoidal lines beneath the LoS line represent the Fresnel zones of the radarand are used to calculate attenuation and refraction.

3.1.6 As there is very little terrain shielding, refinement of the model using highresolution Digital Surface Data and Digital Terrain Data was not consideredworthwhile at this time as it would make very little difference to the overallassessment.

3.1.7 A summary of the LoS results to each turbine is recorded below in Table 1.

Turbine LOS PSR Turbine LOS PSR Turbine LOS PSR

1

Yes AR15

8

Yes AR15

15

Yes AR15

Yes EA5025 Yes EA5025 Yes EA5025

2

Yes AR15

9

Yes AR15

16

Yes AR15


3

Yes AR15

10

Yes AR15

17

Yes AR15


4

Yes AR15

11

Yes AR15

18

Yes AR15


5

Yes AR15

12

Yes AR15

19

Yes AR15


6

Yes AR15

13

Yes AR15

20

Yes AR15


7

Yes AR15

14

Yes AR15

Yes EA5025 Yes EA5025

Table 1: LOS Summary

3.1.8 Both radars have LoS to each of the 20 wind turbines comprising Frodsham WindFarm.



CL-4762-RPT

3.1.9 Radio propagation profile checks were made to the Frodsham Wind Farm and thetotal path loss data were obtained for three points on each wind turbine; the hub,the blade tip and a point midway along the turbine blade. The results from theCEG AR15 PSR to Turbine T1 are shown in Figures 7 to 9.

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Figure 7: Total Path Loss to Blade Tip (125m)



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Figure 8: Total Path Loss to Blade Mid-point (102.5m)



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3.1.10

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Figure 9: Total Path Loss to Nacelle (80m)

The one-way Total Path Loss figures and other pertinent data are entered into aMS Excel spreadsheet to obtain the dB Over Receiver Threshold figures asshown in Figure 10.




Figure 10:

3.1.11 The results from the tothe 3 calculations wereThe results have beenradar. Radar returns>3these values show a higare coloured yellow andB, figures are coloureSignals > 6 dB below tshow that detection is u

3.1.12 The final result is showand is shown at Annex

3.1.13 Using HerTZ Mappervarious elevation angleangle is determined fro

CYRRUS LIMITED 16 of 42

Example of Radar 2-way path loss calculation

tal path calculations were tabulated in a spreadsheet andmade to each turbine, as described in paragraph 2.5.2.colour-coded to indicate likelihood of detection by the

dB above the detection threshold are coloured green ash probability of detection. Those between +3dB and -3 dB

d indicate a possibility of detection. Between -3dB and -6d orange to show only a small possibility of detection.

he threshold of detection are shaded red as these valuesnlikely.

n in the final column (Total) of each colour-coded chartD.

software it was possible to derive that there would bes from the radar to the different wind turbine tips. Thism, and is depicted by the red circle, in the data at Figure




11. The angles varied between +0.2° and +0.4° for the tips, hub and mid-point ofthe blade.

Figure 11: Profile from CEG AR15 PSR to Frodsham Turbine Tip T1 –Electrical Tilt Angle

3.1.14 For ease of interpretation, the data in Figure 12 is shown in dB relative to themaximum antenna gain rather than absolute values. From this data we candetermine the addition attenuation (or reduction in gain) that occurs for targets offaxis of maximum gain.

Figure 12: Graph of Elevation Angle v Relative Gain for 0° Antenna Tilt




3.1.15 From Figure 10 it can be seen that a target at +0.2° elevation would have areduction in gain of 16.5dB compared to the maximum antenna gain for anantenna with a 0° mechanical tilt setting. Setting a positive mechanical tilt anglehas the effect of shifting the Relative Gain curve in Figure 10 to the left. Forexample, a +1.0° mechanical tilt would alter the gain reduction from 16.5 dB to23dB for a target at +0.2° elevation from the antenna, as shown in red on Figure10.

3.1.16 As the new radar is yet to be commissioned, the mechanical tilt of the antennahas not determined at this time. To allow a comparison of radar performance, allmodelling has been conducted with an assumed mechanical tilt of 0° for the newradar.

3.1.17 The LoS data is re-processed through an Excel spreadsheet introducing dBcorrections using the new Antenna Gain parameters and the corrected Pd valuesobtained.

3.1.18 The results from the 2-way path loss and Pd calculations were tabulated in aspreadsheet and the results obtained, with the Pd value being colour coded tofacilitate ready assessment. It is important to consider that, as the target getsfurther into the Cosecant2 beam, the sensitivity of the PSR increases. Therefore,an additional correction – based on the target’s elevation angle to the PSRantenna – has to be included in the dB over threshold level calculations. This isobtained by establishing from HerTZ Mapper the electrical tilt angle at each targetheight. The resulting correction value is included in the relevant spreadsheetsand factored into the colour coded final results.

3.1.19 Results of Pd calculations are tabulated at Annex D. Both the existing and newradars are expected to detect all of the turbines.




4 Potential Mitigation

4.1 Overview

4.1.1 Mitigation measures taken to combat the appearance of turbine-induced clutteron radar displays can be either operational or technical in nature. Operationalmeasures are those actions taken by Air Traffic Control Officers while providingAir Traffic Service to aircraft in the vicinity of clutter. On the other hand technicalmeasures might involve making alterations to the radar so as to ‘remove’ theturbine-induced clutter or by introducing a variety of suppression measures to theradar system so as to prevent the turbine-induced returns being presented on theradar displays.

4.2 Operational Mitigation

4.2.1 Frodsham lies within the Hawarden promulgated radar vectoring area. Although adetailed study has not been undertaken, it is not thought that the Frodshamturbines will affect the promulgated ATC Surveillance Minimum Altitudes.


Figure 13: Position of Frodsham relative to CEG runway 22 arrivals.

4.2.2 As illustrated in Figure 13, the Frodsham development lies adjacent to the arrivaltrack to CEG runway 22. The chart illustrates the procedural approach tracks,however, most large aircraft will be radar vectored onto the final approach track tobe established on the extended runway centreline as early as possible. This is toallow the aircraft to make a stabilised approach guided by the Instrument LandingSystem.




4.2.3 The scope for operational mitigation is limited as the turbines are located close tothe runway extended centreline. In these circumstances, it is not possible to avoidthe clutter by the required margin of separation.

4.2.4 It is best practice to accept any aircraft from LJLA as clear of clutter andconflictions and intercept the ILS at least 8NM from touchdown. Vectoring aircraftaround the clutter to intercept the final approach closer to Hawarden is not inaccord with best safety practice which calls for a stabilised approach rather thanmanoeuvres late in the approach phase.

4.2.5 Whilst the Frodsham development is technically under airspace controlled byLiverpool John Lennon Airport (LJLA), A Letter of Agreement cedes radar controlof the airspace to CEG for arrivals to runway 22. Whereas it could be argued thatLJLA could remain responsible for CEG inbounds until clear of Frodsham, thiswould require LJLA to have suitable radar mitigation in place. Late handover ofinbound traffic from LJLA to CEG is undesirable to CEG ATC due to increase inATC and pilot workload in the final stages of the approach.

4.3 Technical Mitigation

4.3.1 Having established that there is clear LoS to all of the turbines at Frodsham byboth radars at CEG, and a high probability of detection of those turbines, therewould be little benefit, if any, from altering either the turbine size or theconstellation layout. Nevertheless, it may be possible to introduce a technicalsolution that would prevent any turbine-induced clutter from appearing on ATCradar displays.

4.3.2 Some investigation has been undertaken by QinetiQ in the development of stealthtechnology for wind turbine blades. Whilst initial test results are encouraging, thetechnology is currently immature. Although stealth technology can reduce theapparent Radar Cross Section (RCS) of the turbine and blades, it is not clear thatthe reduction will be sufficient to remove the turbine clutter from Hawarden’sradar.

4.3.3 Assuming that the new radar has a tracker function, the creation of Non-Automatic Initiation Zones (NAIZ) above wind farms can provide effectivemitigation against the appearance of turbine-induced clutter on radars which useplot extracted data. NAIZ prevent the generation of ‘new’ tracks above theturbines while allowing mature tracks to pass through unaltered. Unfortunately,they do not prevent ‘seduction’ of mature tracks by the turbines. Similarly,overflying aircraft can ‘seed’ new random tracks within the turbine clutter. Forthese reasons, NIAZ is not considered a sufficiently robust option.

4.3.4 Optimisation of the radar processor, using clutter maps and gain optimisation,could remove the turbine clutter in the affected range/azimuth cells, but this wouldalso serve to supress wanted returns from aircraft. Due to the position of thewindfarm, under a critical part of the approach flight track, this option is notconsidered further.

4.3.5 Shadowing of the turbines by the introduction of artificial screens would removethe turbine clutter, but would have an adverse effect on radar performance overthe whole critical sector of the runway 22 approach. For this reason, screening isdismissed as a viable option.




4.3.6 The provision of ‘in-fill’ radar data from an alternative radar site or new installationat a suitable location, not in LoS to the proposed development and offering therequired level of coverage, could also prevent any turbine-induced clutter beingdisplayed on radar displays at CEG. This is an established mitigation principleused elsewhere.

4.3.7 Two possible in-fill radar solutions could be the existing radars at St Annes andWarton. Both radars do not have LoS to any of the Frodsham turbines and areunlikely to detect them.

4.3.8 LoS modelling was conducted from St Annes and Warton at 125m agl. Theresults are shown in Figures 13 and 14.


Figure 14: LoS from St Annes Radar to 125m agl

4.3.5 Figure 14 indicates that there is no LoS to the Frodsham wind turbines from StAnnes Radar.





Figure 15: LoS from Warton Radar to 125m agl

4.3.6 Figure 15 indicates that there is no LoS to the Frodsham wind turbines fromWarton radar.

4.3.7 Initial assessments indicate that these two radars have LoS to circa 1,000’ aglover the Frodsham site. Full Pd calculations would need to be undertaken toestablish the operational acceptability once the actual radar configurationparameters are known. Ultimately, this would need to be verified by flight testing.

4.3.8 Other options for providing an infill source are an additional radar sensor; thismay be a standard PSR, Cambridge Consultants Holographic Radar, C-Speed orQinetiQ VERIFEYE™ solution. Whilst these may provide suitable technicalperformance, the cost is likely to be high compared to using existing radarinfrastructure. It should be noted that apart from using a standard PSR, the othersolutions discussed are unproven at this time.

4.3.9 Provision of third party radar data to provide technical mitigation will require aService Level Agreement between CEG and the data supplier to addressavailability and integrity to satisfy CEG safety management obligations. It isanticipated that the identified solution will need to support the lifecycle of theFrodsham windfarm development.

4.3.10 Irrespective of the technical mitigation solution implemented, a full safety caseaddressing the technical and operational aspects will be required to satisfy bothlocal Safety Management Systems and national regulatory requirements.

4.3.11 Integration of an infill source to the Radar Display System (RDS) at CEG may beachieved with an external radar data combiner. This would allow an infill solution




to be achieved without changes or modifications to the configuration of the RDSand related system safety approval.




5 Conclusions

5.1 Summary

5.1.1 Technical analysis indicates that both the AR15 and EA5025 radars atHawarden Airport would have a clear and uninterrupted LoS to each of theturbines at Frodsham.

5.1.2 Pd calculations suggest that the turbines would be detected by both radars atHawarden.

5.1.3 Due to the location of Frodsham relative to the approach to Runway 22,operational mitigation to allow CEG radar controllers to provide a radar serviceto inbound aircraft is not readily achievable.

5.1.4 A variety of technical measures exist which could provide effective mitigation,ranging from stealth turbines to the use of radar Range Azimuth Gain Mapping,creation of NIAZs above the wind farm, or the provision of infill coverage from analternate radar source.

5.1.5 Realistically, the only proven technology currently available for technicalmitigation is an infill solution. St Annes and Warton radars do not have LoS tothe turbines and could be considered as an infill data source. Alternatively, infilldata could be provided by an additional radar sensor.

5.1.6 It is assumed that Liverpool John Lennon Airport PSR is also significantlyaffected by the Frodsham development and will probably require an infill solutionto achieve an acceptable level of service. The same infill radar source wouldalso serve to mitigate the effects on CEG PSR.

5.1.7 It is possible that other mitigation technologies may come to maturity prior to theFrodsham development becoming operational. Cyrrus is aware of progress inseveral areas of radar technical mitigation which show some promise to removeor reduce the effects of windfarm clutter, however the efficacy of such solutionsare as yet unproven. In the timescales of agreeing a radar technical mitigationsolution for Frodsham, infill is currently the lowest risk and most viable provenoption.




A Abbreviations and acronyms

agl Above Ground Level

amsl Above Mean Sea Level

ATC Air Traffic Control

CAA Civil Aviation Authority

CEG Chester Hawarden Airport

LJLA Liverpool John Lennon Airport

LoS Line of Sight

NIAZ Non-Automatic Initiation Zone

OS Ordnance Survey

Pd Probability of Detection

PSR Primary Surveillance Radar

SRTM Shuttle Radar Topography Mission




B Turbine and PSR Data

B.1 PSR Data:

PSR OSGBEasting

OSGBNorthing

AntennaElevation (AOD)

MinimumDetection

AntennaTilt

HawardenRadar

Current

334167 364803 21.72m -104dBm +0.3°

HawardenRadarNew

334180 364840 27.45m -110dBm Not yetdetermined

B.2 Turbine Data:

TurbineNumber

OSGBEasting

OSGBNorthing

TurbineNumber

OSGBEasting

OSGBNorthing

1 347434 377279 11 348057 376779

2 347585 377504 12 348525 377158

3 347840 377647 13 348868 377157

4 348080 377804 14 350055 379522

5 348312 377964 15 350478 379279

6 347598 376950 16 350243 379060

7 347864 377110 17 350425 378519

8 348101 377288 18 350702 378685

9 348364 377490 19 350387 378225

10 348652 377645 20 350832 378308




C LOS Results from Hawarden Airport

C.1 Current PSR – Plessey AR15

Frodsham Turbine 1

Hawarden PSR
Terrain
CYRRUS

Frodsham

Frodsham

LOS

LIMITED

Turbine 2

Turbine 3

Turbine

27 of 42




Frodsham Turbine 4

Frodsham Turbine 5

Frodsham Turbine 6




Frodsham Turbine 7

Frodsham Turbine 8

Frodsham Turbine 9




Frodsham Turbine 10

Frodsham Turbine 11

Frodsham Turbine 12




Frodsham Turbine 13

Frodsham Turbine 14

Frodsham Turbine 15




Frodsham Turbine 16

Frodsham Turbine 17

Frodsham Turbine 18




Frodsham Turbine 19

Frodsham Turbine 20




C.2 New PSR – Easat EA5025

Frodsham Turbine 1

Frodsham Turbine 2

Frodsham Turbine 3




Frodsham Turbine 4

Frodsham Turbine 5

Frodsham Turbine 6




Frodsham Turbine 7

Frodsham Turbine 8

Frodsham Turbine 9




Frodsham Turbine 10

Frodsham Turbine 11

Frodsham Turbine 12




Frodsham Turbine 13

Frodsham Turbine 14

Frodsham Turbine 15




Frodsham Turbine 16

Frodsham Turbine 17

Frodsham Turbine 18




Frodsham Turbine 19

Frodsham Turbine 20




D Pd Calculations to Frodsham

D.1 CEG Current PSR – AR15




D.2 CEG New PSR – EA5025

Documents

Frodsham Wind Farm Impact on Hawarden PSR · 2011-11-02 · 2.4 Pd Calculation from Hawarden Radar to Frodsham Wind Farm – VPD Data 2.4.1 The generic 10cm wavelength radar VPD data