wlmb interference study

WLMB Study Report 03/04/11

Dominion Broadcasting, Inc. 1 of 12 MSW

Dennis Wallace 1282 Smallwood Drive

Suite 372 Waldorf, Maryland 20603

(202) 251-7589

A Report Prepared for

WLMB TV Regarding

Impairment of WLMB TV Signal From Proposed Wind Turbines

Near Blissfield and Jasper, Michigan

March 4, 2011



PURPOSE The purpose of this document is to report to WLMB TV and its licensee Dominion Broadcasting Inc. (referred to as WLMB) the results of a study undertaken by Meintel, Sgrignoli, & Wallace, LLC (MSW) to determine the potential impact of the construction of a wind farm, near the WLMB TV transmission facility, on WLMB’s digital television service and coverage area.

The firm of Meintel, Sgrignoli, & Wallace has extensive experience with wind turbines and their impact on communications signals and particularly with regard to the impact on television signals. MSW has conducted numerous evaluations as well as field tests in a variety of locations around the United States. MSW has provided consulting services to Broadcasters as well as Wind Farm Developers on numerous issues related to analog and digital television reception, impact studies, propagation predictions, field testing, mitigation of interference, and other aspects of wind farm development.

PROPOSED WIND TURBINE AND WLMB-TV PARAMETERS MSW undertook a study to determine the possible impairment to reception of the WLMB-TV signal within its current service area with the addition of approximately 84 wind turbines in areas east of the WLMB-TV transmitter site. WLMB-TV provided MSW with a list of proposed wind turbine locations that was based upon information provided by the wind farm developers to the Federal Aviation Administration (FAA) to conduct the FAA obstruction evaluations (OE) for the proposed wind turbine sites.

As noted in this information, the 84 proposed wind turbines for which the FAA OE was conducted (listed in Appendix A), indicates that the proposed heights for the wind turbines will be approximately 497 feet above ground level (AGL). The study utilized this height for determining the impact on WLMB reception from the turbines.

WLMB TV FACILITY STUDY PARAMETERS

WLMB TV Transmitting Antenna Height (AGL) 512 Feet AGL

WLMB TV Effective Radiated Power (ERP) 10KW

WLMB TV Channel (Frequency) Channel 5 (79 MHz)

WLMB Antenna Pattern (Model) Directional (Dielectric THA-S4SP-2M/8H-1-R

WLMB Site Coordinates (NAD 27) 41-44-41 N 84-01-06 W

WIND TURBINE STUDY PARAMETERS

Wind Turbine Location Per Appendix A

Wind Turbine Height 497 Feet AGL



Based upon these facility parameters MSW was able to determine the potential impact of the wind turbine heights and locations on the WLMB TV signal. The WLMB TV transmitting antenna is mounted with a center of radiation at 512 feet AGL. As noted above, the heights of the proposed wind turbines are 497 feet Above Ground Level (AGL) which would put the blades of the turbines in the main beam of the WLMB transmitting antenna. This is demonstrated in Figure 1 below.

Figure 1 Height of Turbine Blades and Transmitting antenna are essentially the same.

In our experience, in order for nearly co-located turbines to not impair the propagation of the TV signal for the nearby transmitter, the height of the turbine blade at the top of its rotation should be no greater than 25% the height of the television transmitting antenna. In addition, the turbines would need to be clustered very close to the base of the transmitter such that the blades would not intersect a line that would be drawn from the transmitting antenna to the ground based upon a depression angle of greater than 30-50º. In this case, the wind turbines are spread out over a very large area and at heights that would certainly intercept the WLMB TV signal path between the transmitting antenna and the receiver location.

This signal interception by the blades of the wind turbine would result in severe degradation to the WLMB digital television signal. This degradation would include severe dynamic multipath effects, high-speed Doppler shifts in the signal, and large variation in the signal level. Further, due to the frequency of operation of the WLMB-TV signal (channel 5 / 79MHz) the wavelength of the WLMB signal at this frequency is approximately 12.5 feet. This long wavelength would like exacerbate the effects of the wind turbine impairment.

Signal Passing Through Blades



STUDIES OF IMPAIRMENT FROM WIND TURBINES Several approaches were used to evaluate the impact of the wind turbines on the WLMB-TV signal. First, all of the proposed wind turbine locations were plotted on a map along with the WLMB facilities. Based upon the heights given for the wind turbines and the WLMB transmitting antenna, a geographic region of interest can be developed that indicates those areas that are likely to lose reception and those areas where reception will likely be significantly impaired causing intermittent reception. These maps are contained in Appendix B.

Second, an additional study technique was employed using the Longley-Rice propagation prediction model. This model using the Federal Communications Commission’s (FCC) OET-69 study parameters was used to generate a coverage and service map (Appendix C) which shows the potential impairment on the coverage and service using a “static” model. In other words, in this study the wind turbines are treated as static objects that are not moving. Therefore, this model prediction is considered to be conservative and the actual impairment is likely to be much worse than predicted with this technique. However, the maps and study do indicate severe impairment to the WLMB signal over much of the area that is currently covered by WLMB. The study indicates that these areas would lose reception with the addition of the wind turbines.

OVER THE AIR RECEPTION IMPAIRMENT Utilizing the results of the LR study, an estimate of the number of households and population that would lose the ability receive WLMB over-the-air was prepared. This estimate (Appendix D) shows that WLMB would lose at a minimum approximately 37.4% of its currently served households after construction of the wind turbine project is completed. This equates to approximately 319,351 households that would be impaired.

The study estimates that approximately 815,067 (36.9% population) persons would lose potential over-the-air reception of WLMB. As this study was based upon the second method (Longley-Rice Model with FCC OET-69 Parameters) described above, it is likely that these estimates are conservative and the actual numbers may be much higher. Obviously, this would significantly impact viewership of the WLMB signal. In addition, the viewers within the impaired areas may not have alternative signal distribution choices to receive WLMB as discussed in the next section.

CABLE & SATELLITE IMPAIRMENT MSW studied the locations of the various cable and satellite TV providers that rely upon over the air reception to receive the WLMB signal for distribution to their subscribers. Based upon the locations of these signal pick-up points (head-ends), we find that a substantial number of cable and satellite subscribers would be impaired.

Below we provide a list of the systems that we believe would not be able to reliably receive the WLMB signal over the air for distribution to their subscribers.



IMPAIRED CABLE & SATELLITE SUBSCRIBERS

SYSTEM NAME AREA SERVED SUBSCRIBERS

Buckeye Cable Toledo and surrounding areas 128,000

Charter Communications Monroe, Blissfield, Huron, Etc. 16,118

Comcast Adrian, Addison, Monroe, Etc. 21,000

DirecTV Satellite Toledo DMA 21,000*

DISH Network Satellite Toledo DMA 21,000*

D&P Cable Petersburg, Blissfield, Etc. 4,059

TOTAL 211,177 * Estimated number of subscribers.

We estimate that the lost homes would represent approximately 65.2% of the households that receive the WLMB signal from satellite and cable. The net result would be that only approximately 112,953 subscribers would not be impaired (34.8%) by degradation to the WLMB signal caused by the addition of the wind farm. Obviously, this results in a significant impact to WLMB viewership and its ability to serve its existing viewers via cable and satellite distribution.

As shown here, this would significantly impair the ability of any alternative distribution platforms to provide the WLMB signal to their subscribers, homes in the impaired areas with degraded or no off-air reception of WLMB would be left with no way to receive the station as cable and satellite would also be impaired.

MICROWAVE LINK IMPAIRMENT MSW also undertook a review of the WLMB Microwave System to determine if any impact would likely result from the operation of the wind farm. WLMB operates a microwave link from its studio in Toledo to its transmitter site near Jasper, MI to deliver its signal for transmission over the air via its transmitter. This STL (Studio-To-Transmitter) link is licensed by the FCC as station call sign WPYL859. It operates at a frequency of 7.0625GHz. The path from the studio to the transmitter is approximately 19.7 miles at a bearing of 249.9ºT. Although it appears that the wind turbines have been specifically spaced to avoid this microwave path, it is not known if there is enough Fresnel Zone clearance for the link to continue to operate reliably with the wind turbines in operation (blade rotating).

From our experience, we would anticipate that this STL link would have some degradation in margin and therefore reliability due to the “narrowing” of the Fresnel Zone clearances with the installation of the wind turbines in their proposed locations.

EMERGENCY ALERT SYSTEM Since WLMB participates in the Federal Communications Commission’s Emergency Alert System (EAS), which provides for the dissemination of emergency information to the stations’ viewers, any disruptions to the reception of WLMB would impact the viewers’ ability receive EAS messages from WLMB in the case of national, local and weather emergencies. Thus, public safety and emergency information distribution may also be impaired.



CONCLUSION Based upon our study and our substantial experience with similar projects, we find that significant degradation and interference to WLMB TV signal will likely result from the construction of the proposed wind turbine farm.

Not only will almost 815,067 potential over-the-air viewers using indoor and outdoor antennas lose reception of WLMB, it is highly likely that approximately 65% of the WLMB viewers (211,177) on cable and satellite systems would lose reception as well.

Our study of the WLMB STL system indicates that it is likely to be negatively impacted by the wind farm, and although no turbines are in the direct line-of-sight path of the STL, it is likely that Fresnel Zone clearances will be diminished and may result in less reliable operation or failure of the STL link. This would result in WLMB not being able to deliver its programs from its studios to its transmitter site, and therefore, directly impact all of its viewers.

It is clear from our studies that the construction and operation of the wind turbine farm near the WLMB transmitter site would have a substantial negative impact on the viewers of the station including the dissemination and delivery of emergency EAS messages.

It is also noted that those areas adjacent to the proposed turbines and areas north and west of the proposed wind turbines would likely experience similar impairments to receiving the other Toledo television stations using over-the-air antennas. These areas would likely encounter similar degradation of television reception and the EAS messages associated with the impaired stations.

Submitted this 4th day of March, 2011

________________________________________

Dennis W. Wallace, C.B.T.E.

Managing Partner

Meintel, Sgrignoli, & Wallace, LLC

1282 Smallwood Drive, Suite 372

Waldorf, MD. 20603

(202) 251-7589



QUALIFICATIONS OF THE FIRM The firm of Meintel, Sgrignoli, & Wallace is a consulting firm that specializes in Digital and Analog Television and Radio Transmission Systems, Consumer and Professional Electronics, Technical Software applications and Propagation Studies, as well as engineering education (seminars, tutorials, etc.). The firm’s principals have been engaged in the practice of engineering for well over twenty years. The firm has provided technical and policy consulting on a number of issues related to Digital Television. The firm has conducted numerous studies and field studies related to wind turbine interference and its impact on television and radio signal reception. The following are biographies of each of the partners of the firm.

William Meintel Bill Meintel holds a degree in Electrical Engineering and has experience in the communications field since 1970. After graduation, Bill was employed by the Federal Communications Commission (FCC), first as a field engineer and then in the Mass Media Bureau’s Policy and Rules Division. While in Policy and Rules, Bill served as the division’s computer expert and directed the development of several major computer modeling projects related to spectrum utilization and planning.

He entered private practice in 1989, and has been heavily involved in technical consulting, computer modeling, and spectrum planning for the broadcast industry. In April 2005, Bill merged his consulting practice (Techware) into the firm Meintel, Sgrignoli, & Wallace, where he is a partner and principal engineer.

Mr. Meintel co-authored a report for the NAB on spectrum requirements for Digital Audio Broadcasting (DAB), created a plan for independent television broadcasting for Romania and has been extensively involved in spectrum planning for digital television (DTV) in both the U.S. and internationally. Mr. Meintel wrote the software to conduct DTV interference analysis and OET-69 studies for the FCC. Bill is a member of IEEE and Tau Beta Pi.

Gary Sgrignoli Gary received his BSEE and MSEE degrees from the University of Illinois (Champaign-Urbana), and was a design engineer with Zenith Electronics Corporation in their Research and Development group for 27 years before leaving to become a DTV broadcast consulting engineer. In 2005, Gary merged his consulting practice (Sgrignoli Consulting) into the firm Meintel, Sgrignoli, & Wallace, where he is a partner and principal engineer.

Gary has worked in the R&D design area on television "ghost" canceling, cable TV scrambling, and cable TV two-way data systems before turning to digital television transmission systems. Since 1991, he has been extensively involved in the 8-VSB digital transmission system design, its prototype implementation, and its lab and field tests. He holds 35 U.S. patents (many related to DTV and 8-VSB transmission), is a recipient of the prestigious IEEE Matti S. Siukloa award, and was selected as SBE Educator of the Year for 2005.

Gary was involved with the DTV Station Project in Washington DC, helping to develop DTV RF test plans. He has also been involved with numerous television broadcast stations around the country, training them for DTV field testing and data analysis, and has participated in numerous DTV over-the-air demonstrations with the Grand Alliance and the ATSC, both in the U.S. and abroad. In addition to publishing technical papers and giving presentations at various conferences (NAB, BTS, ICCE, SBE, NTA, CBA), he has presented many VSB transmission system seminars around the country since 1998. Gary is a member of the IEEE and the SBE.



Dennis Wallace Dennis Wallace has an extensive background in digital Television Systems. Dennis managed all the Laboratory RF Testing of the Grand Alliance ATSC HDTV System, having served as the RF Systems Engineer at the Advanced Television Test Center (ATTC). He managed test plans, configurations, and operations for Grand Alliance Testing and several data-casting systems. In early 2009, we has awarded a Technical “Emmy” plaque by the Academy of Television Arts and Sciences for contributions he made to the ATTC and the development of Digital Television. Prior to joining ATTC, Dennis held positions in Field Operations Engineering, Applications Engineering, and was Product Manager for two television transmitter manufacturers.

In July 1997, Dennis founded Wallace & Associates, a broadcast engineering and consulting firm specializing in digital television, RF propagation measurements, spectrum policy issues, and technical consulting. His clients include major broadcast groups, The DTV Station Project, ATTC, Trade Associations, and both Professional and Consumer Electronics Manufacturers. In April 2005, Dennis merged his firm (Wallace & Associates) into the firm of Meintel, Sgrignoli, & Wallace, where he is a partner and principal engineer.

He has worked on the Broadcast side as well, holding Chief Engineer and Operations Manager positions with both radio and television stations.

Dennis has authored several papers on the topics of Digital Television transmission and results of testing of the DTV systems, which have been published in the IEEE Transactions and other publications. Dennis has been a presenter at the IEEE Broadcast Technology Symposium, NAB, and several SBE Conferences, as well as providing DTV presentations for SCTE and IEEE Chapters. He has made extensive field measurements of both Digital and Analog Television and Radio systems, including over 5,000 DTV field measurements.

In 1999, Mr. Wallace was awarded the prestigious Matti S. Siukola award by the IEEE Broadcast Technology Society. Mr. Wallace is a Certified Broadcast Television Engineer by the Society of Broadcast Engineers. He is also a member of the IEEE Broadcast Technology Society, SMPTE, an Associate member of the Federal Communications Bar Association, and is active on several industry standards committees and the ATSC.



Appendix A

WIND TURBINE PROPOSED LOCATIONS

WLMB REPORT APPENDIX A WIND TURBINE LOCATIONS

Case Number City State Latitude Longitude Site ElevationStructure Height

Total Height

2009‐WTE‐11989‐OE Blissfield MI 41° 46' 11.43" N83° 58' 29.33" W 717 494 1211























APPENDIX B

MAPS OF AREAS LIKELY TO BE IMPACTED BY INTERFERENCE FROM WIND TURBINES

Street Atlas USA® 2007 Plus

AREA OF NO RECEPTION

Area of Intermittant Reception


Data use subject to license.

© 2006 DeLorme. Street Atlas USA® 2007 Plus.

www.delorme.com

TN

MN (6.4°W)0 8 16 24 32 40

0 12 24 36 48 60

mikm

Scale 1 : 1,400,000

1" = 22.10 mi Data Zoom 7-2







www.delorme.com

TN

MN (6.6°W)0 2 4 6 8 10

0 3 6 9 12 15

mikm

Scale 1 : 350,000

1" = 5.52 mi Data Zoom 9-2







www.delorme.com

TN

MN (6.4°W)0 ½ 1 1½ 2

0 1 2 3

mikm

Scale 1 : 75,000

1" = 1.18 mi Data Zoom 11-4







www.delorme.com

TN

MN (6.5°W)0 ½ 1 1½ 2

0 1 2 3 4

mikm

Scale 1 : 100,000

1" = 1.58 mi Data Zoom 11-0







www.delorme.com

TN

MN (6.6°W)0 1 2 3 4 5

0 2 4 6 8 10

mikm

Scale 1 : 250,000

1" = 3.95 mi Data Zoom 9-6



APPENDIX C

Longley-Rice Propagation Model Prediction Maps



APPENDIX D

IMPACTED HOUSEHOLD AND POPULATION COUNT INFORMATION

State County Population Households Population Households Population HouseholdsINDIANA STEUBEN 153 54 153 54 0.00% 0.00%MICHIGAN HILLSDALE 18,322 6,767 18,322 6,767 0.00% 0.00%MICHIGAN JACKSON 19,866 7,579 19,866 7,579 0.00% 0.00%MICHIGAN LENAWEE 98,890 35,930 98,878 35,925 -0.01% -0.01%MICHIGAN LIVINGSTON 13,676 4,671 607 206 -95.56% -95.59%MICHIGAN MONROE 145,945 53,772 136,748 50,526 -6.30% -6.04%MICHIGAN OAKLAND 9,182 3,858 0 0 -100.00% -100.00%MICHIGAN WASHTENAW 308,141 119,084 282,252 109,582 -8.40% -7.98%MICHIGAN WAYNE 749,442 293,187 80,850 29,713 -89.21% -89.87%OHIO DEFIANCE 34,943 13,407 34,943 13,407 0.00% 0.00%OHIO FULTON 42,084 15,480 42,084 15,480 0.00% 0.00%OHIO HANCOCK 58,649 23,207 9,172 3,239 -84.36% -86.04%OHIO HENRY 29,210 10,935 29,210 10,935 0.00% 0.00%OHIO LUCAS 455,054 182,847 452,776 182,044 -0.50% -0.44%OHIO OTTAWA 19,844 7,454 4,164 1,500 -79.02% -79.88%OHIO PAULDING 870 330 870 330 0.00% 0.00%OHIO PUTNAM 24,232 8,506 24,232 8,506 0.00% 0.00%OHIO SANDUSKY 11,634 4,296 1,195 435 -89.73% -89.87%OHIO SENECA 12,057 4,617 2,567 1,056 -78.71% -77.13%OHIO WILLIAMS 34,368 13,281 34,368 13,281 0.00% 0.00%OHIO WOOD 121,065 45,172 119,303 44,518 -1.46% -1.45%Total 2,207,627 854,434 1,392,560 535,083 -36.92% -37.38%

APPENDIX D WLMB Predicted Service Comparison

Without Wind Farm With Wind FarmNumber

With Wind FarmPercent

wlmb interference study

Documents

wlmb signal

wlmb reception

wlmbtv signal channel

wlmb facilities

wlmbtv parameters msw

wlmb tv signal path

msw wlmb study report

wind turbine heights