NAT'L INST. OF STAND & TECtAlllDb DtiMMlfi

NIST

PUBLICATIONS

NIST Technical Note 1519

and

NTIA Report 01-387

Predicted and Measured Field Strengths

in the Boulder, Colorado, Area from

Two Proposed Terrestrial Digital

Television Tower Sites

Christopher L. Holloway, Frank H. Sanders, and Paul M. McKenna

''"iONSJ Institute for Telecommunication Sciences

National Telecommunications and Information Administration

U.S. Department of Commerce

100

.U5755

m.1519

2001

C.2

Institute of Standards and Technology

Administration

tment of Commerce NIST CENTENNIAL
IIIII
NIST Technical Note 1519

and

NTIA Report 01-387

Predicted and Measured Field Strengtlis in the

Boulder, Colorado, Area from Two Proposed

Terrestrial Digital Television Tower Sites

Christopher L. Holloway

Radio-Frequency Technology Division

Electronics and Electrical Engineering Laboratory

National Institute of Standards and Technology

Boulder, CO 80305

Frank H. Sanders and Paul M. McKenna

institute for Telecommunication Sciences

National Telecommunications and Information Administration

Boulder, CO 80305

May 2001

.,^wN

U.S. Department of Commerce

Donald L Evans, Secretary

National Institute of Standards and Technology National Telecommunications and Information Administration Karen H. Brown, Acting Director John F. Sopko, Acting Assistant Secretaryfor Communications and Information
National Institute of Standards

and Teclinology

Teclinical Note 1519

Natl. Inst. Stand. Techno!.

Tech. Note 1519

144 Pages (May 2001)

CODEN: NTNOEF

U.S. Government Printing Office

Washington: 2001

For sale by the

Superintendent of Documents

U.S. Government Printing Office

Stop SSOP.

Washington, DC 20402-0001

Phone: (202) 512-1800

Fax: (202) 512-2250

Internet: bookstore.gpo.gov

and

National Telecommunications and

Information Administration

Report 01 -387
Executive Summary

In this report, we have analyzed the expected electric (E) field strengths in the Boulder

area from two proposed terrestrial DTV transmitter locations, the Eldorado Mountain site and the Squaw Mountain site. The Eldorado Mountain and Squaw Mountain sites were

selected from the set of candidate sites because these two possible sites bound the

propagation environment that would occur at both the Table Mountain National Radio

Quiet Zone (NRQZ) and the Department of Commerce (DOC) Laboratories in Boulder.

The Eldorado Mountain site affords substantial line-of-sight coverage over the Boulder

area, while the Squaw Mountain site affords only indirect (diffractive) coverage over the

same area. The other possible tower sites fall between these two types of propagation

conditions.

The goals of this work were to determine the expected E-field strengths at the Table

Mountain NRQZ located north of Boulder, Colorado and at the DOC Laboratories

located at 325 Broadway in Boulder, Colorado. This study also assessed the potential

impacts of the proposed sites on a broad range of Federal Government research and

metrology programs that depend upon a relatively quiet radio-frequency electromagnetic

environment (see Section 8). The DOC conducted tests and analyses to assess whether Efield strengths produced by the DTV transmissions from either proposed site could meet

the FCC's regulatory hmits for the Table Mountain NRQZ. In addition, tests and analyses were performed to ascertain the impact of DTV transmissions from either proposed site on measurement efforts that are performed on a regular basis at the DOC Laboratories.

In this study, measured and predicted E-field strengths are used to estimate the E-field

strengths in the Boulder area for the proposed transmitter antenna heights of two possible

transmitter locations, Eldorado Mountain and Squaw Mountain. With these predictions,

we were able to determine the E-field strengths at both the DOC Laboratories and at the

Table Mountain NRQZ. The results show that at the Table Mountain NRQZ, the

predicted E-field strengths are about 0.3 V/m for a single transmitter on Eldorado

Mountain at 1.0 MW EIRP. This number exceeds the FCC's regulatory (47 CFR

73.1030) limit by about an order of magnitude (approximately a factor of 10). At that

level, research at the Table Mountain NRQZ will be compromised. The results also show

that the E-field strengths at the DOC Laboratories for a single transmitter located on

Eldorado Mountain are about 1 V/m for 1.0 MW EIRP. These field strengths are high

enough to possibly jeopardize the sensitive measurements done on a routine basis at the

DOC Laboratories, as discussed in Section 8. By comparison, the results show that, at the Table Mountain NRQZ, the predicted E-field strengths are about 0.002 V/m for a

single transmitter located on Squaw Mountain with 1.0 MW EIRP. These field strengths are within the FCC's Table Mountain NRQZ regulatory (47 CFR 73.1030) limit. Thus,

the results indicate that a transmitter could be located at Squaw Mountain without

violating the FCC's regulatory limit or adversely impacting research at the Table

Mountain NRQZ.

The data presented in this report illustrate that E-field strengths on the order of 0.5 V/m

to 1 V/m could be present at the DOC Laboratories. The studies presented in Section 8

illustrate only a few of the potential problems that may be experienced at the DOC

Laboratories.

ill
The measured and modeled data presented in this report are for an EDRP of 1 MW. As

indicated in the report, some of the DTV channels have maximum power allocations of

1.64 MW EIRP. The E-field strengths presented here can be transformed to a 1.64 MW

EIRP by multiplying the data shown in all the figures by a factor of 1.3 (which would

increase the E-field strengths by 30 %). This would result in even higher E-field strengths

in the Boulder-Denver area than those presented here, and could cause even greater

interference at both the DOC facilities (see Sections 5 and 9). The FCC indicated in

references cited in the report that in the future, adjustments to the allocated power levels

may be granted under some situations, in order to allow power levels higher than 1.64

MW. If these higher power levels are granted, the result would be even higher E-field

strengths in the Boulder-Denver area than those presented here.

For DTV reception, the FCC specifies a minimum (i.e., for noise Limited DTV reception)

E-field strength of 41 dB|xV/m (0.1 1 mV/m) for a receiving antenna at a height of 9.14 m

(30 ft). Using the ITM prediction model, we also predicted the coverage areas where the

FCC's minimum field strength for acceptable reception is met or exceeded. From the

results shown here, it is seen that the two proposed transmitter locations (Eldorado

Mountain and Squaw Mountain) have basically the same DTV coverage areas (see

Section 6). However, the data in these results show that a transmitter on Squaw Mountain

will not violate the FCC's regulatory limits protecting the Table Mountain NRQZ, if these transmissions occur on the currently allotted DTV frequencies.

In a recent document (cited in this report, see Section 9), the Advanced Television

Systems Cormnittee (ATSC) Task Force on RF System Performance has suggested that

in order to overcome the indoor DTV reception problem, field strengths at the 9.14 m

(30 ft) reference height may need to be increased substantially to 97 dBp,V/m. This is an

increase of 56 dB over the FCC minimum E-field strength, which is equivalent to an

increase by a factor of approximately 631 in field strength. This 56 dB increase can be

obtained by either substantially reducing the coverage area of DTV reception, by

reducing the DTV payload data rate or by increasing the allocated transmitter power

levels by an unrealistic 56 dB. Obviously, if transmitter power levels are increased to compensate for the indoor reception problem, higher E-field strengths than those

presented in this report could occur at both the Table Mountain NRQZ and at the DOC

Laboratories, as well as at other areas throughout Boulder.

While the results presented in this report are for omnidirectional or onmi-azimuthal

directional antenna patterns, the actual antennas that will be used for the proposed tower

will have some type of antenna pattern associated with them. The report discusses

(Section 7) how the results presented here can be used once the antenna pattern of the

proposed towers are known.

IV
Contents

1. INTRODUCTION 2

1.1 Electric Field Strength 2

1.2 Organization of the Report 6

2. SPECTRUM SURVEY AT THE NRQZ AND AT THE DOC

LABORATORIES FOR 30 MHz TO 960 MHz 8

2.1 Measurement System 8

2.2 Measurement System Calibration and Correction to Incident Field

Strength 9

2.3 Measurement System Data Collection Algorithms and Parameters 9

2.4 Data Storage and Analysis 10

2.5 Table Mountain NRQZ Spectrum Survey Results: Vertically Polarized

Measurements 11

2.6 DOC Laboratories Spectrum Survey Results: Vertically Polarized

Measurements 11

2.7 Analysis of Existing Television Signal Environment: Horizontally

Polarized Measurements 1

1

3. DESCRIPTION OF THE MEASUREMENT SYSTEM FOR DTV E-FIELD

STRENGTH MEASUREMENTS 19

3.1 Calibration of System 20

3.2 Data Analysis: Measured E-field Strengths 20

4. COMPARISON OF MEASURED AND PREDICTED E-FIELD

STRENGTHS 25

5. PREDICTED E-FDELD STRENGTHS FOR THE PROPOSED TOWER

HEIGHTS , 28

6. DTV E-FDELD STRENGTH REQUIREMENT 29

7. ANTENNA PATTERN EFFECTS 30

8. EFFECTS OF BROADBAND TRANSMISSION ON SENSITIVE

MEASUREMENTS.... 31

9. SUMMARY AND CONCLUSION 35

10. REFERENCES 39

APPENDIX A: MEASURED E-FIELD STRENGTHS OF THE 1998 AND 2001

SPECTRUM SURVEY 101

APPENDIX B: MEASURED POWER LEVELS 125
Trade Name Disclaimer

Certain commercial equipment, instruments, or materials are identified in this report to adequately specify conditions used in obtaining the reported information. Such

identification, implied or specific, does not represent a recommendation or endorsement

of the companies or the products by the National Institute of Standards and Technology

or the National Telecommunications and Information Administration, nor does it imply

that the materials or equipment identified are necessarily the best available for the

purpose.

VI
Predicted and Measured Field Strengths in the Boulder, Colorado, Area from

Two Proposed Terrestrial Digital Television Tower Sites

Christopher L. Holloway

National Institute of Standards and Technology

Boulder, Colorado 80305

Frank H. Sanders and Paul M. McKenna

National Telecommunications and Information Administration

Boulder, Colorado 80305

A study was perfoimed to determine the increase in ambient electromagnetic

field strengths that would result from a proposal to locate a cluster of terrestrial digital television (DTV) transmission towers in proximity to the Department of

Commerce GDOC) Laboratories in Boulder, Colorado. The primary objective of

this study was to assess the impact on a broad range of Federal Govermnent

research and metrology programs that depend upon the relatively quiet radiofrequency electromagnetic environment. Radio-wave propagation measurements were performed for two terrestrial DTV frequencies (533 MHz and 772 MHz),

and used to verify predicted DTV electric field strengths obtained fi-om the DOC

Irregular Terrain Model (ITM). The measured data were also used to determine

the variation in received signal strength over small distance intervals. Radio- wave propagation measurements were performed at both frequencies using two

possible mountaintop transmitter locations, Eldorado Mountain and Squaw

Mountain. The first (Eldorado Mountain) affords substantial line-of-sight

coverage over the Boulder area, and the second (Squaw Mountain) affords only

indirect (diffractive) coverage over the same area. The two propagation

conditions from each site, direct and indirect, respectively, are compared to the

ITM predictions. The relative variations in measured and predicted signal

strengths are compared as a function of frequency and of propagation conditions.

Measured and predicted data were found to be in close agreement. This provides

confidence that the theoretical predictions of received signal strengths at given

locations in the Boulder area are accurate. It was found that in some locations,

the ambient field strengths for 1 MW of transmitter power from a single station

will exceed 1 V/m.

Key words: digital television (DTV), field strength measurements. Irregular

Terrain Model (TTM), National Radio Quiet Zone (NRQZ),

propagation modeling, spectrum survey
1. INTRODUCTION

The Federal Conununications Commission (FCC) has mandated that all full-service

(high-power) television broadcasters be transmitting a digital television (DTV) signal and

be prepared to terminate their analog television (TV) broadcasts by 2006 [1]. In the

United States, the analog television broadcast standard, or National Television System

Committee (NTSC), allocates 6 MHz of bandwidth per channel [2, 3]. The high-power

TV broadcasters have each been provided with a paired digital channel, usually in the

"core" TV channels (2 through 51). If market penetration of digital television is sufficient, then the intent of the FCC directive is for analog TV broadcasts to cease and

for some of the analog spectrum to be returned to the public for other communication

services. In this report, the term DTV includes high-definition digital TV (HDTV).

Current analog TV channels 52 through 69 will be reassigned to other uses, including the

provision of additional spectrum for public-safety users (including a number of

interoperability channels); some of this spectrum will also be auctioned for commercial

wireless telecommunications network applications. Table 1 shows the present analog

frequencies for the different TV chaimels along with the new DTV frequencies for some

TV channels in the Denver, Colorado, Designated Market Area (DMA). Some of these

TV channels have been authorized to transmit at effective radiated power (ERP) levels as high as one megawatt (1 MW), where ERP is defined as the product of the power

supplied to the antenna and its gain relative to a half-wave dipole in a given direction [4].

The allocated power levels for these TV channels are also shown in table 1. Also shown

in this table are the allocated power levels in units of equivalent isotropically radiated

power (EIRP), defined as the product of the power supplied to the antenna and its gain

relative to an isotropic antenna in a given direction [4]. Note, EIRP = 1.64 ERP. EIRP is used throughout this report.

In Reference [1], the FCC indicates that in the future, adjustments to the allocated power

levels may be granted under some situations, which would allow transmitter power levels

higher than 1 MW ERP (1.64 MW EIRP). The Further Notice of Proposed Rulemaking

(FNPRM) [5] indicates that maximum ERP of 5 MW (or 8.2 MW EIRP) is possible.

1.1 Electric Field Strength

A minimum DTV E-field strength of 41 dB^V/m (1.12x10"^ V/m) at a receiving antenna

height of 9.14 m (30 ft) is assumed adequate to provide satisfactory reception, as recommended by the FCC [1]. Note that dB^V/m refers to decibels relative to 1 ^V/m.

The table of allotments was designed to essentially replicate a broadcaster's current

analog Grade B coverage area with digital signal strengtfis greater than or equal to the

minimum DTV electric field strength, while attempting to minimize analog-into-digital,

digital-into-analog, and digital-into-digital co- and adjacent-channel interference with

signals of other broadcasters. Transmitter power consumption is a significant operational

cost, and it is therefore critical for broadcasters to have confidence that field strength

prediction models are accurate, so that excessively high power levels are not transmitted.

(High transmitter power can also increase deleterious interference, both into-digital and
into-analog, for distant stations.) It is also critical for broadcasters to understand the

amount by which received DTV signal strengths may vary spatially within predicted

contours, so that power levels throughout the coverage area will be high enough to compensate for localities at which the actual field strength drops below the noise-limited

field strength.

Reception may be possible with a 9.14 m outdoor antenna (this height assumes mounting

3 m above the rooftop of a two story residence) or indoor antenna; however, significant

problems with reception with indoor antennas have been reported [6]. In this report, the

Advanced Television Systems Committee (ATSC) Task Force has suggested that in order

to overcome the indoor DTV reception problem, field strengths at the 9.14 m (30 ft) reference height may need to be increased substantially to 97 dBfiV/m. This is an

increase of 56 dB over the FCC 41 dB^V/m, which is equivalent to an increase by a

factor of approximately 631 in field strength. This 56 dB increase can be obtained by

either substantially reducing the coverage area of DTV reception or by increasing the

allocated transmitter power levels by an unrealistic 56 dB.

In the Colorado Front Range (the Denver metropolitan area), several sites have been

proposed as possible locations for the new DTV transmitting antenna towers. Two of

these proposed sites are addressed in this report. They are on Eldorado Mountain, which

is located just south of Boulder, Colorado, and on Squaw Mountain, which is located just

south of Idaho Springs, Colorado. Note, the Eldorado Mountain and Squaw Mountain

sites were chosen in this study because these two possible sites bound the propagation

environment that would occur at both the Table Mountain NRQZ and the DOC

Laboratories. The Eldorado Mountain site affords substantial line-of-sight coverage over

the Boulder area, and the Squaw Mountain site affords only indirect (diffractive)

coverage over the same area. The other possible tower sites fall between these two types

of propagation conditions. The Department of Commerce (DOC) conducted tests and

analyses to address whether DTV transmissions from these two proposed sites will

produce E-field strengths that exceed the regulatory FCC Limits for the Table Mountain

National Radio Quiet Zone (NRQZ) north of Boulder, Colorado [8]. In addition, these

tests were used to ascertain whether DTV transmissions from these proposed sites will

have an adverse impact on measurement efforts that are performed on a regular basis at the DOC Laboratories located at 325 Broadway in Boulder, Colorado (hereafter referred

to as the DOC Laboratories).

The DOC Laboratories in Boulder comprise three Federal research agencies: the National

Institute of Standards and Technology (NIST), the National Telecommunications and

Information Administration's (NTIA) Institute for Teleconmiunication Sciences (ITS),

and the National Oceanic and Atmospheric Administration (NOAA). All three of these

laboratories perform different types of measurement activities at both the Broadway

location and at the Table Mountain NRQZ. The Table Mountain NRQZ is one of only

two national radio quiet zones in the United States (the other being the National Radio

Quiet Zone in West VirginiaA^irginia [9]). The Table Mountain NRQZ provides

scientists and engineers with a research environment where external radio signals

(sometimes called "ambient radio noise") are kept to a minimum. The integrity of this

NRQZ is mandated by both Federal regulation and state law, [8] and [10] respectively.
These regulations and laws require that signal strengths from various transmitters must

not exceed specified E-field strengths within the Table Mountain NRQZ in frequency

bands above 1.6 MHz (table 2). Other public and private institutions besides the DOC

Laboratories use this NRQZ for research purposes. These include the United States

Geological Survey (USGS), the National Center for Atmospheric Research (NCAR), the

Deep Space Exploration Society (DSES), the Radio Amateur Satellite Corporation

(AMSAT), and Coherent Technologies, to name a few.

In order to address the concerns of the DOC, propagation models were used to predict the

E-field strengths at the two DOC locations (the Broadway Laboratories and the Table

Mountain NRQZ). Various wave-propagation models have been developed that can be

used for this task. They range from very simple free-space models to more complex

irregular terrain models. Unfortunately, simple free-space models can be used only under

certain conditions. A simple free-space model will give accurate results only when

scatter-free line-of-sight conditions exist. However, the free-space model is a good

starting point in considering broadcast field strengths and will be briefly summarized.

Consider the antenna in figure 1, which is connected to a transmitter. Assume that this

system is isolated in free space (i.e., no scattering objects are in the vicinity of the

antenna). With this assumption, it can be shown [11-14] that the power density (^), and

E-field can be related as follows

^ = ^

fW/m^^ (1)

and

|£| = V^ [V/m], (2)

where

EIRP = P,G,

.

(3)

In these two expressions, EIRP is the equivalent isotropically radiated power, P, is the

input power at the transmitter antenna terminals (in units of watts), and G, is the gain of

the transmitter antenna, which is in general a function of directional angles 6 (elevation)

and (azimuth), relative to the antenna, in spherical coordinates. G, is the gain relative

to an isotropic antenna (often expressed in units of dBi, where dBi refers to antenna gain

in decibels relative to an isofropic antenna). R is the distance (in units of meters) from

the transmitter antenna to an observation point (the location of a receiver), and rj is the

free-space wave impedance given by the following

7? = 120;? = 377 [Q.]. (4)

4
From the expressions given in equations (1) and (2), it is observed that the power density

iP decays as —- and the magnitude of the E-field decays as — . This is illustrated in

figures 2 and 3, where the magnitude of the E-field and the power density are plotted as a

function of R for an EIRP of 1 MW. Also shown in these figures are the IEEE radio

frequency (RF) population exposure limits for a typical TV frequency [15], as well as some international limits [16]. Figure 2 also shows the 30 mV/m FCC Table Mountain

NRQZ limit [8], which is given in table 2 for the DTV frequencies. Notice that for a

distance of 23 km (the distance from Eldorado Mountain to the Table Mountain NRQZ)

the free-space field value is about an order of magnitude higher than the FCC NRQZ

hmit. By inserting the NRQZ E-field limit into the expression given in equations (1) and

(2), the minimal distance at which the FCC NRQZ requirement is met for a given

transmitter power level and antenna gain can be obtained as follows:

nun

-ll/2

4n\Ef

[m]. (5)

For \e\ = 30 mV/m, P, = 1 MW, G, = 1 (EIRP=1 MW), this reduces to R^=m [km] (or 114 mi). (6)

Figure 1 represents an idealization of a realistic wave-propagation environment. A more

realistic environment is depicted in figure 4. The figure shows a transmitting antenna on

a hillside that propagates energy toward a receiving antenna near the ground. In this

scenario the radio waves that propagate toward the receiving antenna are not simply the

free-space environment shown in figure 1. As the receiving antenna moves along the

ground and traverses the terrain profile, the E-field strength deviates from the free-space

calculations due to effects of the terrain. In a line-of-sight (LOS) path, the transmitter can be physically seen fi-om the receiver location, e.g., points A or C in figure 4. The E-field

for a LOS path has contributions from a direct ray, reflected ray(s), and, to a lesser extent,

firom diffracted rays. The direct ray corresponds to the free-space result discussed above.

The reflected rays are caused by multiple reflections due to objects in the environment

(e.g., the ground, mountains, hillsides, trees, rocks, cars, buildings, people, etc.). The

diffracted rays result from scattering fi-om the edges of these objects. In a non-line-ofsight (non-LOS) path, the transmitter cannot be seen from the receiver location, e.g., point B in figure 4. The E-field for a non-LOS path is the result of contributions from

only reflected rays and diffracted rays. In these cases, the direct, reflected, and scattered

rays may add up constructively or destructively to cause the received signal strength to be

larger or smaller than that predicted using the free-space model. In order to calculate the

field strength in these more complex environments, sophisticated irregular terrain models

must be used.

There are various irregular terrain models available for these calculations [17-19]. In the

calculations presented in this report, the ITS Irregular Terrain Model (TTM) developed at
the DOC Laboratories is used [17-20], which is based on the work of Longley and Rice

[21]. This model was developed during the 1950's and 1960's and has been continuously

improved throughout the years. For the predictions reported here, this model uses USGS

digital terrain elevation data to determine the actual terrain profiles for the area of

interest. Once the terrain features are determined, electromagnetic models are used to calculate the E-field strengths at any desired location given a transmitter's height,

antenna gain, and power level. The ITM is widely used by the broadcast and

communication industries.

In this report, we use the ITM to predict the E-field strengths at the DOC Laboratories

and at the Table Mountain NRQZ for transmitters located at the proposed Eldorado

Mountain and Squaw Mountain sites. However, to verify that the modeled results for the

two proposed locations and tower heights are accurate, comparison to measured data is required. Since measurements of E-field strengths based on proposed transmitter tower

heights (approximately 116 m (380 ft) at Eldorado Mountain and approximately 60.96 m

(200 ft) at Squaw Mountain), and at the maximum proposed transmitting power levels

(i.e., 1 MW ERP or 1.64 EIRP) are impractical, measurements were carried out at reduced transmitter antenna heights and power levels. The proposed transmitter tower

heights for the two sites were obtained from either the landowners or pubhc documents.

The measurements were performed in the geographic area of interest to the DOC

Laboratories at 533 MHz and 772 MHz, i.e., frequencies near the lower and upper ends

of the UHF DTV spectrum allotment for several of the local broadcast stations. The

propagation measurements were performed with fixed transmitters placed on the two

mountaintops and a land-mobile receiver and data recording system. The two

mountaintop locations used were the proposed Eldorado Mountain and Squaw Mountain

sites. The mobile van-based receiver system was driven throughout the Boulder area, and

E-field strengths were measured as a function of location across the area. Both line-ofsight and obstructed (shadowed) propagation paths were encountered during the

measurements. For model validation, measured field strengths were compared to ITM

calculated data as a function of location and frequency. The data also revealed the

variation in received field strength as a function of location, for both line-of-sight and

shadowed propagation. Once the model predictions were confirmed with the

measurements, the ITM propagation model was used to calculate the E-field strengths for

the proposed transmitter heights and power levels at the two proposed sites.

12 Organization of the Report

This report is organized as follows: Section 2 presents recentiy measured E-field strength

at both the Table Mountain NRQZ and the DOC Laboratories, illustrating that the FCC

E-field strength limits are currently maintained at the NRQZ and exhibiting the current

field strengths at the DOC Laboratories. In Section 3, the measurement system is described and the measured data for the two different transmitter sites are shown. Also in

Section 3, the measured data were scaled to the proposed transmitter power level to indicate the expected E-field strengths at both the DOC Laboratories and at the Table

Mountain NRQZ north of Boulder. In Section 4, predicted E-field strengths obtained

from the ITM are compared to the measured data. In Section 5, calculated E-field
strengths are presented for the proposed antenna heights and power levels for the two

different proposed transmitter sites. Section 6 discusses the FCC field strengths

recommended for DTV reception. Also in this section, field strength plots for the FCCrecommended 9. 14 m (30 ft) receiving antenna height are presented to illustrate predicted

DTV reception in the Boulder-Denver area from the two proposed sites. In Section 7,

antenna pattern effects are discussed. Section 8 discusses the effects of broadband

transmission on sensitive measurement systems. Finally, we summarize the results and

discuss the possible impact of the proposed sites on the scientific activities at both the

DOC Laboratories and at the Table Mountain NRQZ facility.

In this report all measured data are scaled to a 1 MW EIRP and all the predicted E-field

strengths are calculated for a 1 MW EIRP. Use of a 1 MW EIRP facilitates rescaling

both the measured and calculated field strengths to any other desired EIRP level, as the

need arises.

Table 1. Frequencies and power allocations for analog frequencies for the different TV

channels along with the new DTV frequencies for some TV channels in the Denver,

Colorado, Designated Market Area (DMA).

Current NTSC

channel

Current frequency

bands (MHz)

New

DTV

channel

New DTV

frequency bands

(MHz)

Allocated DTV

ERP

(MW)

Allocated DTV

EIRP

(MW)

2 54-60 34 590-596 1.0 1.64 4 66-72 35 596-602 1.0 1.64 6 82-88 18 494-500 1.0 1.64 7 174-180 17 488-494 1.0 1.64 9 186-192 16 482-488 1.0 1.64 12 204-210 38 614-620 1.0 1.64 14 470-476 15 476-482 0.099 0.164

20 506-512 19 500-506 0.248 0.407

31 572-578 32 578-584 0.233 0.383

41 632-638 40 626-632 0.0748 0.129

50 686-692 51 692-698 0.0817 0.134

59 740-746 43 644-650 0.01448 0.024

Table 2. Specified E-field strength limits for the Table Mountain NRQZ for the VHF and

UHF fi-equency bands.

Frequency band (MHz) E-field limit (nV/m) E-field limit (dB^V/m)

1.6-470 10,000 80.0

470-890 30,000 89.5

>890 1,000 60.0
2. SPECTRUM SURVEY AT THE NRQZ AND AT THE DOC

LABORATORIES FOR 30 MHz TO 960 MHz

Spectrum occupancy measurements provide data on expected E-field strengths and

probabilities of occurrence that are essential for assessing the degree of utilization at a given site or in a given area. NTIA has published a set of reports [22-25] documenting

spectrum occupancy between 100 MHz and 19.7 GHz in some of the largest metropolitan

areas in the United States.

In June 1998, a spectrum survey (E-field strength measurements) was performed inside

the Table Mountain NRQZ and at the DOC Laboratories to determine E-field strengths

using a vertically polarized receiving antenna. In April 2001, a spectrum survey was

performed inside the Table Mountain NRQZ and at the DOC Laboratories to determine

E-field strengths for a horizontally polarized receiving antenna. The results of these

surveys are presented in this section.

2.1 Measurement System

The NTIA Radio Spectrum Measurement System (RSMS) was used to perform the field

strength measurements (or spectrum survey). Hardware, software, and methodology used

for this survey were the same as for earlier surveys referenced above. Those reports may

be consulted for detailed descriptions of broadband spectrum survey techniques used at the Table Mountain NRQZ.

The RSMS is a mobile, self-contained computer-controlled radio-receiving system

capable of many measurement scenarios over a frequency range of 30 MHz to 22 GHz.

Figure 5 is a view of the RSMS with telescoping masts raised and antennas mounted for a broadband spectrum survey such as was performed at Table Mountain. The large box on

the rear of the RSMS is an RF-shielded enclosure containing the measurement

equipment.

The masts may be raised to as much as 9 m above ground level. For collection of

spectrum data between 30 MHz and 960 MHz at Table Mountain, the forward mast was

raised to full height. An onmi-azimuthal directional antenna with a nominal frequency

range of 30 MHz to 1000 MHz was used to receive signals. A 12 m RF cable connected

the antenna to the measurement system input port, located inside the van.

The RSMS measurement system is shown as a block diagram in figure 6. It consists of

two independent systems, each with its own antennas, receiver and signal processing

equipment, and controller/data-recording computers. The two are designated System 1 and System 2. System 1 is on the right-hand side of figure 6. For the Table Mountain

NRQZ survey, this system was used to measure signals between 30 MHz and 960 MHz.

System 1 is built around a Hewlett-Packard 8566B spectrum analyzer and a HewlettPackard 85685A preselector. The preselector provides low-noise preamplification for a

typical measurement system sensitivity of about 10 dB across the range of 30 MHz to 960 MHz. The preselector also provides bandpass filtering ahead of the preamplification,

to protect the measurements firom the effects of strong signals in close proximity to the

measurement frequencies. Bandpass filters are varactors below 500 MHz and are yttrium8
iron-gamet (YIG) above 500 MHz. Variable attenuation is available ahead of the

bandpass filtering in the 85685A, but was not required for the NRQZ measurements.

The measurement system was controlled via a PC-compatible controller running customdeveloped ITS measurement software. The computer program set all measurement

parameters to operator specifications. Parameters are varied on a band-by-band basis (see

measurement system data collection algorithms, below). The computer performed

measurements on a band-by-band basis, in accordance with a preconfigured sequence for

the bands between 30 MHz and 960 MHz. The computer recorded all measurement data

to an internal hard drive for subsequent retrieval and analyses at the NTIA/TTS laboratory.

2.2 Measurement System Calibration and Correction to Incident Field Strength

The measurement system was calibrated at least once every 24 hours during the spectrum

survey. RSMS cahbrations make use of a NIST-traceable standard noise diode at the

antenna coimection point. The procedure is standard Y-factor, in which measured power

with the noise diode turned on is compared to measured power with the noise diode

turned off. System noise figure and gain are computed across the entire frequency range

to be surveyed. Reports [22] through [25] contain detailed descriptions of this technique

as implemented for the RSMS.

As data are collected, all measured amplitudes are corrected for the system gain.

Corrected amplitudes are stored for later retrieval and analysis. These data are in units of

decibels relative to 1 mW (dBm) for a measurement system with 50 Q. impedance.

Measured data are converted to other units, if necessary, during post-measurement data

analysis. The conversion to incident field strength is accomphshed by implementing the

following equation (see References [11] and [26] for details):

\E\=P^+ 77.2 + 201og(/) - G,

,

(7)

where \E\ is the magnitude of the E-field strength at the antenna in units of dB|xV/m,

Pmtas is the measured power in units of dBm, / is the frequency in units of megahertz

(MHz), and G, is the gain of the measurement antenna (the receiver antenna) at frequency

/ in units of dBi. Note, dBm refers to decibels relative to 1 mW, and dBi refers to antenna gain in decibels relative to an isotropic antenna.

23 Measurement System Data Collection Algorithms and Parameters

RSMS data collection algorithms and parameters are tailored to the characteristics of the

signals that typically occupy each spectrum band. The two fundamental algorithms that are used are swept-frequency and stepped-frequency. Swept-frequency measurements

require that data be collected as the measurement system is continuously tuned across a

firequency range of interest. Swept-frequency measurements are used in non-radar bands.

Stepped-frequency measurements require that data be collected at fixed-tuned

frequencies, with detectors (usually peak) operated at each frequency for specified
intervals of time. Stepped-frequency measurements are used in radar bands. For the

purposes of this survey, stepped-frequency measurements were performed between

420 MHZ and 450 MHz and between 900 MHz and 930 MHz. All other bands utilized

swept-frequency measurements.

Measurement parameters within each band are specified for maximum probability of

intercept (POI). POI is maximized through careful selection of intermediate frequency

(IF) bandwidth, video (post-detector) bandwidth, and detector type (e.g., peak versus

average). The IF bandwidth is selected to match or slightly exceed the typical signal

bandwidth within each band. Video bandwidth equals or slightly exceeds IF bandwidth.

Detection may be either peak or sample, depending upon signal characteristics. Details

are provided in References [22] through [25].

During the one-week period of this survey, the bands were visited in accordance with a

preconfigured measurement sequence. The sequence was designed to ensure that each

band was measured at least once during each hour of the diurnal cycle, and usually bands

were measured several times during each hour. Bands that normally show highly

dynamic changes in activity (e.g., land mobile radio bands) were visited much more

frequently than low-dynamic bands (e.g., broadcasting). Details are described in

References [22] through [25].

2.4 Data Storage and Analysis

All data for the Table Mountain NRQZ survey were recorded to the controller PC's

internal hard drive. The data were later archived. Data initially recorded within each band

showed maximum, minimum, and average signal strengths for periods of about a minute

each, as described more fully in Reference [22] through [25]. Typically, each of these raw recordings was produced from dozens or even hundreds of individual spectrum

analyzer sweeps.

When data were retrieved for analysis, all raw recordings for each band were combined

to show the overall maximum, minimum, and average signal strengths within each band

during the entire measurement period of one week. The cumulative data for all bands

between 30 MHz and 960 MHz for the 1998 spectrum survey for a vertically polarized

antenna are presented in Appendix A of this report (figures A.l through A.34), and

discussed in Sections 2.5 and 2.6. The cumulative data for all bands between existing TV

channels from the 2001 spectrum survey for a horizontally polarized antenna are presented in Appendix A of this report (figures A.35 through A.43), and discussed in

Section 2.7.

10
2.5 Table Moimtain NRQZ Spectrum Survey Results:

Vertically Polarized Measurements

Table 3 summarizes the measured occupancy and strengths on a band-by-band basis for

the Table Mountain NRQZ. All signals that are required to meet the 47 CFR 73.1030

limits within the Table Mountain NRQZ were observed to be in compliance. Moreover,

virtually all other measured signals within the NRQZ also meet the limits. This may be

partly due to the relatively rural location of the NRQZ. Of the handful of signals that do

not meet the limits (and which are not required to meet them, because they are mobile

systems), the measurement data indicate that field strengths are typically exceeded only

briefly.

The results of this spectrum survey allow us to conclude with certainty that for vertically

polarized measurements the NRQZ is, in fact, quiet. It therefore remains a useful and

necessary location for radio experiments that cannot be performed in the presence of

high-level background signals.

2.6 DOC Laboratories Spectrum Survey Results:

Vertically Polarized Measurements

As a comparative data set, a spectrum survey identical to the one at the Table Mountain

NRQZ was performed at the DOC Laboratories in June 1998. The same measurement

hardware and software were used as that for the Table Mountain survey. The RSMS was

located next to the NIST groundscreen, an outdoor antenna range located on the west side

of the DOC site. The location afforded a limited line-of-sight view of the city of Boulder,

but was well within a propagation shadow for most Denver-area broadcast transmitters

(on Lookout Mountain, near Golden, Colorado).

The groundscreen measurements were run for a week. Plots of the measured E-field

strengths are shown in Appendix A, figures A. 18 through A.34. Table 4 summarizes the

measured occupancy and strengths on a band-by-band basis for the NIST groundscreen.

In most bands between 30 MHz and 960 MHz, the NIST groundscreen shows

significantly higher signal strengths, and often more ambient noise, than the same bands

within the Table Mountain NRQZ. Therefore, the Table Mountain NRQZ is an important

resource for carrying out high-sensitivity, low-noise radio-wave measurements in these

bands.

2.7 Analysis of Existing Television Signal Environment:

Horizontally Polarized Measurements

The 1998 spectrum surveys at the Table Mountain NRQZ and the NIST groundscreen at the DOC Laboratories were performed with vertically polarized measurement antennas.

This polarization, although useful for measuring most incident signals (land mobile radio,

and radar, for example), was cross-polarized to most (horizontally polarized) television

signals. To provide maximum coupling to television signals, the 1998 measurements were repeated between April 12-20, 2001, at the Table Mountain NRQZ and at the NIST

groundscreen at the DOC Laboratories, this time using a horizontally polarized log

11
periodic antenna (LPA). Measurements were also performed with the LPA at a second

location at the DOC Laboratories, at the end of Wing 4 of Building 1 (the Radio

Building). Other than the antenna used, all measurement conditions and parameters at these locations matched those of the 1998 spectmm survey.

The LPA was pointed in azimuth to maximize received signal strength from ambient

television signals at these locations (that is, approximately toward Lookout Mountain).

The gain of the LPA was factored into resulting measurements of incident field strength

at these locations.

Because several television stations were already transmitting in the Denver area when the

Table Mountain NRQZ was created, transmissions from those stations were

grandfathered at preexisting levels exceeding the Table Mountain NRQZ limits. Those

stations, and the strengths at which they are permitted to exceed the NRQZ thresholds,

are shown in table 5.

The measurement results are shown in figures A.35 through A.43 and are summarized in

tables 6 through 8. In these figures, maximum, minimum, and mean levels during the

measurement period are shown. Additionally, note that the relatively high level of

television carriers at the Table Mountain NRQZ required the insertion of 10 dB of

attenuation in the bands with grandfathered signal strengths when the polarizations were

matched. This attenuation was also used in the measurements in the other television

bands, and at the other measurement locations, for the sake of consistency. This need for

insertion of such attenuation is, in general, undesirable for DOC research programs

conducted at the Table Mountain NRQZ and at the DOC Laboratories (see Section 8).

Table 6 summarizes the measured occupancy and strengths at the different locations for

the 54 MHz through 88 MHz frequency range. Television signal strengths at the Table

Mountain NRQZ are currently at the prescribed limits, including grandfathered signal

strengths for Channels 4 and 6. Background noise levels on Channel 3 (unoccupied) are somewhat higher with horizontal polarization than with vertical polarization. Comparison

of the Table Mountain NRQZ measurements with those performed on the NIST

groundscreen facility and the end of Wing 4 of the NIST/TTS Radio Building on Broadway in Boulder, shows that the received television carrier field-strengths are higher

within the NRQZ than at the DOC Laboratories on Broadway. But, apart from the TV

signals, the spectrum is typically quieter at the Table Mountain NRQZ than at the

Broadway locations. The noisier environment at the DOC Laboratories is due presumably

to extensive development in the Boulder area. The characteristics of the ambient noise on

the DOC Laboratories vary somewhat as a function of antenna polarization and precise

location, but in no case is the ambient noise on the campus totally abated by polarization or location.

Table 7 summarizes the measured occupancy and strengths at the different locations for

the 174 MHz through 216 MHz frequency range. Television signal strengths at the Table

Mountain NRQZ are currently at the prescribed limits, including grandfathered signal

strengths for Channels 7 and 9. Background noise strengths are comparable with

horizontal and vertical polarizations. Comparing the Table Mountain NRQZ

12
measurements with those perfonned on the NIST groundscreen and at the end of Wing 4

of the NIST/TTS Radio Building at the DOC Laboratories, the received television carrier

field strengths are higher within the Table Mountain NRQZ than at the DOC

Laboratories. But apart from the TV signals, the spectrum is typically quieter at the Table

Mountain NRQZ than at the DOC Laboratories. The noisier environment at the DOC

Laboratories is due presumably to extensive development in the Boulder area. The

characteristics of the ambient noise at the DOC Laboratories vary somewhat as a function

of antenna polarization and precise location, but in no case is the ambient noise on the

campus totally abated by polarization or location. The overall higher level of maximum

noise in the 1998 groundscreen measurements, relative to the 2001 groundscreen data,

may be due to the longer period over which the 1998 measurements were conducted.

Table 8 summarizes the measured occupancy and strengths at the different locations for

the 512 MHz through 806 MHz frequency range. Television signal strengths at the Table

Mountain NRQZ are currently at the prescribed limits. Channel 41 appears to exceed the

limit by 1 dB in the graph, but this is within the uncertainty of the measurement (a

conservative estimate of the measurement uncertainty is ±2 dB). Comparison of

measurements at Table Mountain with those performed on the NIST groundscreen and at the end of Wing 4 of the NIST/TTS Radio Building at the DOC Laboratories, shows that

the received television carrier field strengths are typically higher within the Table

Mountain NRQZ than at the DOC Laboratories. But apart from the TV signals, the

spectrum is typically quieter at the Table Mountain NRQZ than at the DOC Laboratories.

The noisier environment at the DOC Laboratories is due presumably to extensive

development in the Boulder area. The characteristics of the ambient noise at the DOC

Laboratories are noted to vary somewhat as a function of antenna polarization and precise

location, but in no case is the ambient noise on the campus totally abated by polarization or location.

Although existing television signals are somewhat higher in amplitude at the Table

Mountain NRQZ than at the DOC Laboratories (due to direct LOS propagation to the

Table Mountain NRQZ versus indirect propagation to the DOC Laboratories), the

ambient noise level at the Table Mountain NRQZ is typically less than at the DOC

Laboratories. The ambient carrier strengths within the Table Mountain NRQZ are within

the limits described in 47 CFR 73.1030, with the exceptions of the grandfathered limits

for Channels 4, 6, 7, and 9.

Due to terrain shadowing of transmissions from Lookout Mountain to the DOC

Laboratories location, NTSC television signals typically have lower field strengths at the

NIST groundscreen facility than within the NRQZ (which has line-of-sight coverage

from most Denver-area NTSC broadcast station locations). This situation will change,

and the Boulder DOC Laboratories will be subjected to significantly higher television

signal strengths, if DTV transmitters are located in hne-of-sight proximity to the DOC

Laboratories. If that occurs, it will make the NRQZ environment even more important as an asset for measurements in the bands occupied by broadcast television. If new DTV

transmitter locations do not have line-of-sight coverage of the DOC Laboratories, then a

situation somewhat similar to the current propagation conditions may continue.

13
Table 3. Summary of the Table Mountain NRQZ spectrum survey: vertically polarized

measurements.

Frequency

range (MHz)

Description of activity measured at the Table Mountain

NRQZ during one week in June 1998

30-54 This band shows litde activity. Only one signal is present full-time. Even the highest

signal measured was more than 20 dB below the NRQZ limit. 54-88 Television chaimels 2, 4, and 6 (measured with a vertically polarized antenna) are the

significant occupants. All these signals are at or below the NRQZ limit. 88-108 This is the FM broadcast band. All signals are below the NRQZ limit. 108-136 Air-traffic-control voice communications and aeronautical navigation aids are observed

in this band. Although not subject to the NRQZ limits, none of these signals exceeded

the limit. 136-174 Land mobile radio signals are observed in this band. Most of these are intermittentiy transmitted. Some approached the NRQZ limit, but none exceeded it Mobile signals are not required to meet the NRQZ limits. 174-216 Television channels 7, 9, and 12 (measured with a vertically polarized antenna) are the

significant occupants. All these signals are at or below the NRQZ limit. 216-225 Litde traffic is observed in this band, and all signals are well below the NRQZ limits. 225-400 LitUe traffic is observed in this band, which is used primarily for military

communications, military air traffic control, and some aeronautical radio navigation

aids. Although these signals do not need to meet the NRQZ limit, all were measured at strengths below the limit

400-406 A few signals are observed in this band, which is used primarily for meteorological

transmitters. None approached the NRQZ limit. 406-420 One signal in this land mobile radio band approached, but did not exceed, the NRQZ

limit. These signals are not required to meet the limit

420-450 No activity is observed in this band, which is used for long-range military radars. No

such radars are operated in the Table Mountain area. 450-470 Heavy traffic is observed in this land mobile radio band. Although these transmitters do

not need to meet NRQZ limits, only three exceeded the NRQZ limit and then only

momentarily.

470-512 Only television channels 14, 17, and 20 (measured with a vertically polarized antenna)

are observed in this part of the spectrum. Their measured signals are below the NRQZ

limit

512-812 UHF television signals (measured with a vertically polarized antenna) are the only

occupants observed in this part of the spectrum. Their measured signal strengths are well below the NRQZ limit

806-902 Despite heavy observed traffic in the cellular telephone and tnmked radio bands in this part of the spectrum, only a single, mobile signal (not subject to the NRQZ limits)

momentarily exceeded the NRQZ threshold during the survey. 902-928 Although signals in this industrial, scientific, and medical (ISM) band are not subject to NRQZ restrictions, all observed signals were below the NRQZ limit with a single,

momentary exception for a single signal. Stepped measurements, performed to observe

radar signals, show no activity. No such radars operate near Table Mountain.

928-932 Pager signals are observed in large numbers and densities, and do exceed the NRQZ

limit They are not however, required to meet the limit

928-960 Special mobile radio (SMR) traffic in this band is observed, and the signal densities were moderate compared to major metrop>olitan areas [22-25]. Many of these signals

exceed the NRQZ limit, although typically for short intervals. These signals are not

required to meet the NRQZ limits.

14
Table 4. Summary of NIST groundscreen spectrum survey at the DOC Laboratories:

vertically polarized measurements.

Frequency

range (MHz)

Description of activity measured at the DOC Laboratories,

during one week in June 1998

30-54 This band shows substantial ambient noise. The same spectrum within the Table

Mountain NRQZ is quieter.

54-88 Carriers for television channels 2, 4, and 6 are 20 dB to 30 dB (measured with a

vertically polarized antenna) lower at the groundscreen than within the NRQZ. This is due to terrain shadowing of the DOC Laboratories from the transmitter locations. Table Mountain obtained line-of-sight propagation to these transmitters. 88-108 This is the FM broadcast band. Signals at the DOC Laboratories are 10 dB to 15 dB

higher than within the NRQZ.

108-136 Air-traffic-control voice communications and aeronautical navigation aids are observed in this band. Power levels are comparable to those measured within the NRQZ, as would be expected for predominantly airborne signals.

136-174 Land mobile radio signals are observed in this band at strengths about 8 dB higher

than vyithin the NRQZ.

174-216 The highest-level carriers in this band at the NIST groundscreen are in the range of

60 dB^iV/m to 70 dB|iV/m field strength, comparable to the highest carriers in this band at the NRQZ (one of which is as high as 78 dB)xV/m). But the groimdscreen

environment is noisier, with peak noise envelope amplitudes of between 35 dBfxV/m

and 40 dB^iV/m. At the NRQZ, by comparison, the peak noise envelope is between

28 dBuV/m and 30 dB^V/m.

216-225 The groundscreen shows more signal activity, and significantly more noise, than

within the NRQZ.

225-400 This spectrum is significantly noisier, and is occupied by more signals for a higher

percentage of time, than within the NRQZ.

400-406 This spectrum is noisier, is occupied by more signals, and shows as much as 40 dB

higher signal amplitude, than within the NRQZ.

406-420 Occupancy of this band is comparable in amplitude and number of signals to the NRQZ. The Boulder campus shows more noise (up to about 30 dBjiV/m) than the NRQZ (at about 20 dB^V/m).

420-450 Noise at the groundscreen location occurs between 70 and 90 dBjiV/m, as con^)ared

to peak strengths of only 60 to 70 dB^iV/m within the NRQZ.

450-470 Signals at the groundscreen are 5 dB to 10 dB higher than within the NRQZ.

470-512 Due to terrain shadowing from television broadcast locations to the DOC

Laboratories, television signals (measured with a vertically f>olarized antenna) in this band are equal to or lower in power at the groundscreen than within the NRQZ.

512-812 Terrain shadowing of the groundscreen location provides UHF television signal

strengths (measured with a vertically polarized antenna) that are comparable to those

within the NRQZ. __^_

806-902 Cellular base station signals are about 8 dB higher at the groundscreen location than

within the NRQZ.

902-928 At the groundscreen, peak envelopes of signals in this industrial, scientific, and

medical (ISM) band are typically at field strengths of 50 dB|LiV/m to 65 dBixV/m.

This is significantly higher than the typical peak envelope strengths of 40 dB|xV/m to 45 dBuV/m within the NRQZ.

928-932 Pager signals at the groundscreen are comparable to those within the NRQZ.

928-960 Special mobile radio (SMR) traffic in this band occurs at about 10 dB higher

strengths than within the NRQZ. Pager signals at the two locations are comparable.

Above 940 MHz, signals at the groundscreen are typically about 20 dB to 30 dB

higher than within the NRQZ.

15
Table 5. Grandfathered television signal strengths at the Table Mountain NRQZ.

Current NTSC

channel

Grandfathered signal strength within the Table Mountain NRQZ (dBfiV/m)Decibels exceeding the Table Mountain

NRQZ limit of +80 dB^V/m

4 84.1 4.1 6 81.8 1.8 7 94.4 14.4 9 94.3 14.3

Table 6. Television signals between 54 MHz and 88 MHz at the different measurement

locations.

NTSC

channel

Table Mountain NIST groundscreen EndofWing4,Bldg. 1

2 With matched polarization on

the measurement antenna,

signal power is just below the

limit (at +79 dBfiV/m).

With matched polarization on the measurement

antenna, Channel 2

maximum signal is +70 dBuV/m.

Maximum measured signal

strength is +65 dBuV/m,

5 dB less than on the groundscreen.

4 With matched polarization on

the measurement antenna,

grandfathered signal strength

is just below the limit (at +83 dB^V/m).

With matched polarization on the measurement

antenna, Channel 4

maximum signal is +78 dBfiV/m. A transient noise spike at 69 MHz

occurred.

Maximum measured signal

strength is +72 dBfxV/m,

6 dB less than on the groimdscreen.

5 With matched polarization on

the measurement antenna,

weak signal from a distant Channel 5 transmitter is observed at a maximum of

about +55 dBuV/m.

With matching

measurement antenna

polarization, a significant

signal (+60 dBuV/m) from

a distant Channel 5

transmitter is noted.

Maximum measured signal

strength is +57 dBuV/m,

3 dB less than on the groundscreen.

6 With matched polarization on

the measurement antenna,

grandfathered signal strength

is just below the limit (at about +81 dB^V/m).

With matched polarization on the measurement

antenna, Channel 2

maximum signal is +73 dBjiV/m.

Maximimi measured signal

strength is +78 dBM-V/m,

5 dB more than on the groundscreen.

16
i

Table 7. Television signals between 174 MHz and 216 MHz at the different measurement

locations.

i

i

NTSC

channel

Table Mountain NIST groundscreen EndofWing4,Bldg. 1

7 With matched

polarization on the measurement anteima,

signal power is just below

the grandfathered limit (at +93 dBuV/m).

With matched polarization on

the measurement antenna,

maximum signal is +61 dBuV/m.

Same comments as for the groundscreen measurements.

9 With matched

polarization on the measurement antenna,

grandfathered signal

strength is below the limit (at+91dB^V/m).

With matched polarization on

the measurement antenna,

maximum signal is +61 dB^V/m.

Same comments as for the groundscreen measurements.

10 With matched

polarization on the measurement antenna, a weak signal from a

distant Channel 10

transmitter is observed at a maximum of about

+35 dBuV/m.

On vertical polarization, a

signal (+25 dB)LiV/m) from a

distant Chaimel 10 transmitter

is noted. This is not seen in the horizontally polarized

measurement, likely because

of temporal variation in the

indirect propagation of this signal.

Not observed in this measurement. This may be

due to temporal variation

in the indirect propagation

of this signal.

11 With matched

polarization on the measurement antenna,

signal strength is well below the limit (at about

+68 dBuV/m).

With matched polarization on

the measurement antenna,

maximum signal is +79 dB|iV/m. This transmitter

is located on a high rooftop a few blocks from the DOC

Laboratories.

Same comments as for the groundscreen measurements.

12 With matched

polarization on the measurement antenna,

signal strength is below

the limit (at about

+75 dB^iV/m).

With matched polarization, a weak signal (+35 dBuV/m) is noted. This Channel's service

is carried on Channel 1 1 in the Boulder area.

Same comments as for the groundscreen

measurements

i 17
Table 8. Television signals between 512 MHz and 806 MHz at the different measurement

locations.

NTSC

channel

Table Mountain NIST groimdscreen EndofWing4,Bldg. 1

31

and

32

Channel 31 is notable for having a paired digital

transmission at Channel 32. Maximum measured carrier strengdi of +75 dBfiV/m is typical for UHF television signals measured at Table

Mm. NRQZ

With matched polarization on

the measurement antenna,

maximum signal is +62 dB^V/m.

Similar results as for the groundscreen measurements.

41 With matched polarization on the measurement

antenna, maximum signal

strength is +91 dBpiV/m.

This matches the maximum

allowed at the quiet zone, to within the measurement

uncertainty of the RSMS.

With matched polarization on

the measurement antenna,

Channel 41 maximum signal

is +96 dBM-V/m. This is the highest television signal

strength measured at any site during any measurement

Similar results as for the groundscreen measurements.

Others With matched polarization on the measurement

antenna, typical maximimi

signal strengths are between

+70 and +85 dBp-V/m. A

total of about 14 television signals are measured within

the band.

With matched polarization on

the measurement anteima,

typical maximum signal

strengths are between +60 and

+80 dBp-V/m. Two signals are observed at strengths of +86

and +92 dBuV/m. A total of

about 15 television signals are measured within the band.

Similar results as for the groundscreen measurements. Note

higher overall noise

strengths than at the groimdscreen.

18
3. DESCRIPTION OF THE MEASUREMENT SYSTEM FOR DTV E-FDELD

STRENGTH MEASUREMENTS

In this section, the measurement system is explained, and measured results are presented

and discussed. The transmitter systems on each mountaintop and the receiver

measurement system in the van were configured as shown in the block diagram of figure

7. The transmitter consisted of two signal generators coupled into a single power

amplifier via a combiner. The amplifier output incorporated a low-pass filter to reduce

harmonic emissions. Figure 8 is an annotated photograph of the transmitter system used on both rnountaintops. The signal was radiated from the first mountaintop (Eldorado

Mountain) near Boulder (see the map in figure 9) via an onmi-azimuthal directional

antenna (with 1.9 dBi gain), mounted 3.66 m (12.0 ft) high at the edge of a chff that

overlooks the Boulder-Denver metro area. The second mountaintop (Squaw Mountain) is located significantly farther fi-om Boulder (also shown in the map in figure 9), giving

little line-of-sight coverage over the measurement area. The transmitter at this site was

similar to that at Eldorado, but a different transmitter antenna was used. The transmitter

antenna was a log periodic array with 6.5 dBi gain and was mounted 8.2 m (26.91 ft) above the ground. This array had a 3 dB beamwidth of 90 deg, and the beam was

centered on the measurement area.

The transmitted signals were continuous, sinusoidal waves. This allowed the

measurement bandwidths in the receivers to be set at sufficiently narrow values to observe the transmitted signals with nominal signal-to-noise ratios of 10 dB or more. The

EIRP levels transmitted from the Eldorado Mountain site were 22.5 dBm and 30.5 dBm

for the 533 MHz and 772 MHz systems, respectively. The EIRP levels transmitted from

the Squaw Mountain site were 35.1 dBm and 43.5 dBm for the 533 MHz and 772 MHz

systems, respectively.

The mobile measurement system, shown in figure 5, used a 1.9 dBi gain omni-azimuthal

directional antenna mounted on a vehicle rooftop at 2.95 m (9.68 ft) above the ground.

As shown in figure 7, the antenna hne was routed to a splitter, and from there the

received signal was coupled to a pair of receivers. Each receiver was dedicated to a single

fi-equency (533 MHz or 772 MHz). Each receiver included a pre-selector (a varactor

bandpass filter to reject strong adjacent-frequency signals) and a low-noise preamplifier

(affording a noise figure of approximately 10 dB for the measurement system).

The preselector outputs were routed to spectrum analyzers. Each spectrum analyzer was

tuned to the applicable frequency, with a zero Hertz frequency span. The IF bandwidth

was set to 10 kHz, and the lowpass video bandwidth was set slightly wider. Positive peak

detection was used. The sweep time was set to 60 s, so that each spectrum analyzer would

record the received signal strength at the applicable frequency for 1 min at a time.

Each spectrum analyzer was controlled via a laptop PC-compatible computer. The

computer downloaded each minute's-worth of data to data files, and then automatically

reconfigured the spectrum analyzers and preselectors for the next minute of data. These

systems were set to run continuously. Thus, received signal strength was continuously

19
measured at each frequency. Seventeen peak amplitude strengths were measured and

recorded per second at each frequency during data acquisition runs.

As the mobile measurement system was driven throughout the Boulder area, a global

positioning system (GPS) receiver was used to track the vehicle's position. Notes were

also kept on the vehicle's location as a function of local landmarks (e.g., road

intersections). The routes driven for this study are shown in figures 10a, 10b, and 10c.

The measurements for each mountaintop were performed on separate days during the

week of January 22, 2001.

3.1 Calibration of System

The transmitter signal strengths coupled to the antennas were verified directly using

calibrated spectrum analyzers. Antenna gain characteristics were taken from

manufacturers' data sheets for the individual antennas used in the study.

The receiver system was calibrated at the antenna output using a noise diode and a

standard Y-factor excess noise ratio calibration technique in which power is measured in

the receiver system with the diode alternately turned on and then off. The complete

system path of RF line, splitter, preselectors, and spectrum analyzers was calibrated with

this technique. System noise figure was typically about 10 dB, and the correction factor

between spectrum analyzer output and true power level was typically about 20 dB. These

numbers were obtained from a noise diode calibration. The noise diode output levels are

traceable to NIST.

Noise diode calibration data were stored in computer look-up tables, and were added

automatically to all measured power levels. All stored data were corrected at the tir; 3 of

collection. Antenna factor data were not incorporated into these stored data; lield

strengths were computed after the measurements were completed, by adding antenna

factor data to the measured power levels in the measurement system circuitry. A

conservative estimate of the measurement uncertainty is ±2 dB.

3.2 Data Analysis: Measured E-fieid Strengths

Recorded data were reduced from noise-diode-corrected measurement units in the

receiver system circuitry (dBm) to pe:ik received field strength in fi^ee space. This was

accomplished by adding the appropriate antenna correction fiiCtors. Four different sets of

data were collected for the two measured frequencies (533 MHz and 772 MHz) at the two

different transmitting sites (Eldorado Mountain and Squaw Mountain). For each

frequency and transmitter location, data were collected at various locations around the

Boulder area. Appendix B presents the actual measured power levels for all the various

locations, frequencies, and transnaitter sites. From the Eldorado Mountain location the

input power to the antenna was 0.115 W (20.6 dBm) and 0.724 W (28.6 dBm) for the

533 MHz and 772 MHz systems, respectively. The gain of the transmitting antenna at the Eldorado Mountain site was 1.9 dBi. From the Squaw Mountain location the input

power to the antenna was 0.724 W (28.6 dBm) and 5.0 W (37 dBm) for the 533 MHz and

20
772 MHz systems, respectively. The gain of the transmitting antenna at the Squaw

Mountain site was 6.5 dBi.

In this analysis, we are interested in the field strengths for 1 MW power radiating out of

the transmitter (i.e., 1 MW EIRP). In lieu of transmitting 1 MW in this experiment, the

measured power level in Appendix B can easily be transformed to any desired transmitter

power level. Since Maxwell's equations are linear, it can be shown that by using the

measured power level presented in Appendix B, received power levels for any given

transmitter power in dBm can be obtained. For a given fi-equency, gain, and distance,

received power is proportional to transmitted power (hence logarithms add) and the

results for an arbitrary transmitter power can be obtained by scaling the measurements

P = P^s-P,+Peff [dBm]. (8)

Here, Pmes is the measured power level given in Appendix B, P, is the power level at the

input to the antenna for the different systems (defined below), and Peff is the input power

level to the antenna that would correspond to 1 MW (90 dBm) EIRP, and is given by the

following

F^ =EIRP-G, =90-G, [dBm], (9)

where G, is the transmitter antenna gain. Recall that for the Eldorado Mountain site the

transmitting antenna gain was 1.9 dBi, and for the Squaw Mountain site the transmitting

antenna gain was 6.5 dBi. Therefore, for the Eldorado Mountain site

P^=88.1 [dBm], (10)

and for the Squaw Mountain site

P^=83.5 [dBm]. (11)

Pt is different for the different sites and the different frequencies used. For the Eldorado

Mountain site

P, =20.6 [dBm] for 533 MHz (12)

P, =28.6 [dBm] for 772 MHz (13)

and for the Squaw Mountain site

P, =28.6 [dBm] for 533 MHz (14)

P, =37.0 [dBm] for 772 MHz. (15)

21
With these various values of P, and P^ , the following expressions can be used to transform the measured power levels to the power level that would be received assuming

1 MW EIRP. For the Eldorado Mountain site

P = Pmes- 20.6 + 88.1 [dBm] for 533 MHz (16)

P = P^, -28.6 + 88.1 [dBm] for 772 MHz, (17)

and for the Squaw Mountain site

P = P^, -28.6 + 83.5 [dBm] for 533 MHz (18)

P = Pmes- 37.0 + 83.5 [dBm] for 772 MHz . (19)

In order to obtain the E-field strengths, the transformed power levels given in equations

(16) through (19) need to be converted to power densities. Given the power in dBm, the

power density is given by the following:

^ = [W/m^], (20) A^ 1000

where Aeffis the effective area of the receiving antenna, which is a function of wavelength

and the receiving antenna's gain [11]:

A^= : [m^], (21)

47t

where Gr is the receiving antenna gain and is 1.9 dBi (1.55) for all the measurements. X is the wavelength, which is equal to 0.563 m (1.85 ft) and 0.389 m (1.27 ft) for a frequency

of 533 MHz and 772 MHz, respectively. Thus, the effective areas for the two different

frequencies are:

A^ = 0.0391 [m^], for 533 MHz, and (22)

A^ =0.0186 [m^], for 772 MHz. (23)

Once the power density is obtained, the E-field can be calculated from equation (2) given

in Section 1.

Figures 11 through 48 show the measured E-field scaled to 1 MW EIRP for the two

proposed sites and the two different frequencies. Figures 1 1 through 20 are the measured

E-field strengths for a transmitter on Eldorado Mountain operating at 533 MHz.

Figures 11 and 12 are the measured data for the DOC Laboratories and the Table

Mountain NRQZ, respectively, while figures 13 through 20 show the measured E-field

strengths for various other locations throughout the Boulder area. It was necessary to perform measurements over a broader geographic area than just the DOC properties to validate the area-specific propagation models that formed the basis of this assessment.

22
Figures 21 through 30 are the measured E-field strengths for a transmitter on Eldorado

Mountain operating at 772 MHz. Figures 21 and 22 are the measured data for the DOC

Laboratories and the Table Mountain NRQZ, respectively, while figures 23 through 30

show the measured E-field strengths for various other locations throughout the Boulder

area.

Figures 31 through 38 are the measured E-field strengths for a transmitter on Squaw

Mountain operating at 533 MHz. Figures 31 and 32 illustrate the measured data for the

DOC Laboratories and the Table Mountain NRQZ, respectively, while figures 33 through

38 illustrate measured data for an area outside of Boulder and an area outside of Golden,

Colorado.

Figures 39 through 46 are the measured E-field strengths for a transmitter on Squaw

Mountain operating at 772 MHz. Figures 39 and 40 illustrate the measured data for the

DOC Laboratories and for the Table Mountain NRQZ, respectively, while figures 41

through 46 illustrate measured data for an area outside of Boulder and an area outside of

Golden, Colorado.

The rapid variation in the measured data is due to the multiple signal (multipath)

reflections that arrive at the receiving antenna as the measurement vehicle is in motion.

Some other interesting features present themselves in these data. For example, for the case when the transmitter is located on Eldorado Mountain, the results for the Table

Mountain NRQZ location exhibit much less variability than the other measured locations.

This is explained by the fact that the Table Mountain NRQZ site has, virtually, a LOS

path from the Eldorado Mountain transmitter and, hence, there are very few objects

(excluding the ground reflection) at the Table Mountain NRQZ that would cause

multipath effects.

Figures 17 and 27 show results for the Eldorado Canyon route for a transmitter on

Eldorado Mountain. Notice how the E-field strengths increase dramatically as the

measurement vehicle emerged out of the canyon onto Highway 93. It should be noted

that the field strengths in the canyon will most likely be higher than the measured results,

if the Eldorado transmitter is raised to its proposed height of 1 15.5 m (380 ft), see Section

5. This is because shadowing in the canyon would be less. Figures 19 and 29 show results

for the Greenbriar loop for a transmitter on Eldorado Mountain. These figures show

measured data for both LOS and non-LOS paths. For the LOS path (on top of Shanahan

Hill at Shanahan Ridge Park, around Fairview High School, and Southern Hills Junior

High), field strengths of 1 V/m and higher are observed. For the non-LOS portion of the

loop, the field strengths drop to about 0.3 V/m.

The effects of moving automobiles are seen in figures 47 and 48. These figures show

measured data obtained at the intersection of Highway 93 and Highway 72, south of

Boulder, for frequencies of 533 MHz and 772 MHz, respectively. Notice the change in

the variation of the measured E-field when the measurement vehicle and/or other vehicles on the road were either in motion or were stopped. In particular, note that when the

measurement vehicle was parked or stopped at the hght, the higher frequency data (figure

23
48) exhibit more variation in the E-field strengths than do the lower frequency data. This

is expected since scattering from automobiles would be more pronounced for short:er wavelengths (i.e., higher frequencies). These differences in the field variation are also

due to the fact that higher frequency signals experience more rapid phase variation, which

can alter how the multipath reflections add.

Propagation effects due to terrain features (LOS and non-LOS or shadowing) for a

transmitter on Eldorado Mountain can readily be seen for the data collected for the 28*^

Street route, the Broadway route, and the McCaslin loop (see figures 13 through 16 and

figures 23 through 26). For example, on the 28*^ Street route (figures 13 and 23) notice

the very strong signal strength until the intersection of 28* (Highway 36) and Broadway

is reached. At that point the road dips into a valley and no LOS path is present (i.e., the

road dips into a terrain shadowed region). Similar results for the Broadway route are observed (see figures 14 and 24). For this route we see strong signal strengths at the top

of the Table Mountain NRQZ, but the signal decreases as the measurement vehicle drove

off the top of Table Mountain. The field strengths stay low throughout the northem part

of Boulder on Broadway (this part of the route is shadowed from Eldorado Mountain),

and as the measurement vehicle approached Arapahoe Avenue, the field strengths

increase. The trend of increasing field strengths continues as the vehicle emerged into a LOS situation on south Broadway. Finally, the McCaslin loop results are shown in

figures 15, 16, 25, and 26. The variation in the E-field due to the terrain features was

observed for this route as well. In particular, notice how the field strengths increase to about 1 V/m when the measurement vehicle drove through NGAR's parking lot on the

top of Table Mesa.

The measured E-field strengths at both the DOC Laboratories and at the Table Mountain

NRQZ facility are examined next. Figures 12 and 22 show the measured E-field

strengths at the Table Mountain NRQZ for a transmitter located on Eldorado Mountain

for frequencies of 533 MHz and 772 MHz, respectively. From these figures it is seen that

the measured E-field strengths exceed the FCC's regulatory requirements, which is unacceptable for research applications at the Table Mountain NRQZ. Figures 11 and 21

show the E-field strengths measured at the DOC Laboratories for frequencies of

533 MHz and 772 MHz, respectively. From these two figures, it is seen that the

measured E-field strengths range from 0.1 V/m to as high as 1 V/m. These high field

strengths at the Broadway site could possibly have an adverse effect on the sensitive

measurements that are performed on a routine basis at the DOC Laboratories, as discussed in Section 8.

Figures 32 and 40 show the measured E-field strengths at the Table Mountain NRQZ for a transmitter located on Squaw Mountain for frequencies of 533 MHz and 772 MHz,

respectively. From these figures it is seen that the measured E-field strengths do not

exceed the FCC limits for the Table Mountain NRQZ.

The measured E-field strengths at the DOC Laboratories for a transmitter on Squaw

Mountain are shown in figures 31 and 39. It is interesting to observe that data in these

figures resemble a Rayleigh type of fading propagation chaimel, which is indicative of a non-LOS, multipath mobile environment [27, 28].

24
The data presented in this section are for an EIRP of 1 MW. Some of the DTV channels

have maximum power allocations of 1.64 MW EIRP. The E-fields presented here can be

transformed to a 1.64 MW EIRP by multiplying the results in all the figures by a factor of

1.3, resulting in even higher E-field strengths than those presented here.

4. COMPARISON OF MEASURED AND PREDICTED E-FIELD STRENGTHS

The data in the last section show measured E-field strengths for the two proposed DTV

tower sites at 1 MW EIRP. The data were collected for a transmitter height of 3.66 m

(12.0 ft) on the cliff edge of Eldorado Mountain (not the proposed 116 m (380 ft) height),

and for a transmitter height of 8.2 m (27 ft) at Squaw Mountain (not the proposed

60.96 m (200 ft) height). In order to verify any calculated E-field strengths at the

proposed tower locations and heights, comparisons to measured data for the lower

antenna heights are needed. In this section, calculated E-fields obtained from the ITM

(Longley-Rice model) are compared to the measured data in the above section.

Using a 1 MW EIRP and the same transmitter and receiver antenna heights as were used

in the measurements, the E-field strengths for a transmitter located on Eldorado Mountain

were calculated using the ITM. Contour plots of E-field strengths for the BoulderDenver area at 533 MHz, for both a horizontally and vertically polarized transmitting

antenna, are shown in figures 49 and 50, respectively. Figures 51 and 52 show the

contour plots of E-field strengths for the Boulder-Denver area at 772 MHz for both a

horizontally and vertically polarized transmitting antenna, respectively. The different

colors on these contour plots indicate different E-field strengths.

Using the results shown in figures 49 through 52, specific locations can be directly

compared to the routes that the measurement vehicle drove to collect the data in the

previous section. Figure 53 shows the calculated E-field strengths for the 28**^ Street

route in Boulder for 533 MHz. These results were calculated using receiver

latitudes/longitudes obtained from the GPS data set collected during the measurements.

Upon comparing the measured (see figure 13) and predicted (or modeled) E-field

strengths, excellent agreement is demonstrated. Both the measured and predicted field

strengths are about 0.7 V/m on the LOS portion of the route (before the Highway 36

intersection). It is also seen that both the measured and the predicted field strengths are about 0.02 V/m on the non-LOS path portion of the route (Highway 36 to the Table

Mountain NRQZ).

Notice, however, that the measured data have much more variability than the predicted

field strengths. As mentioned above, the variability in the measured data is due to the

vehicle's motion and the motion of the local objects relative to the measurement vehicle, as well as the fact that the measured data contain three-dimensional multipath effects.

Reflections reaching the receiver from all directions are indicative of a true threedimensional multipa^ environment. Keep in mind that the predicted E-field strengths do

not have local scatterers (i.e., buildings, cars, people, etc.) in the model. Only the terrain

profile is taken into account. Also, the ITM uses only profile data on the bearing from

25
the transmitter to the receiver location, referred to as the great circle path. Thus,

multipath due to terrain features that are not in the path from the transmitter and the

receiver will not be modeled (i.e., three-dimensional multipath effects are not modeled).

With this noted, this comparison shows that the ITM predictions correlate very well to the measured data for both the LOS and non-LOS portions of this route.

Figure 54 shows the calculated E-field strengths for the Broadway route in Boulder.

Upon comparing the measured E-field strengths (see figure 14) and modeled results,

excellent agreement is again demonstrated. Both the measured and predicted field

strengths are about 0.2 V/m near the Table Mountain NRQZ. In the north Boulder part of

the route, both the measured and predicted field strengths are about 0.02 V/m. Both

results show that field strengths increase as the measurement vehicle climbed out of the

shadowed region south of Arapahoe Avenue. Both results also show field strengths of

1 V/m and higher on Highway 93.

Figure 55 shows the calculated E-field strengths for the McCaslin loop in the Boulder

area. Upon comparing the measured (see figures 15 and 16) and modeled results,

excellent agreement is again demonstrated. Both the measured and predicted field

strengths are about 1 V/m and higher for the Highway 93 portion of the route. Also

notice that both the measured and predicted results show dips in the field strengths

ranging fi-om 0.01 V/m to 0.1 V/m for some of the non-LOS locations. Notice that both

the measured and predicted results show the same behavior in the field strengths as the

measurement vehicle drove to and from the top of the NCAR site, with the field strengths

at the top of NCAR reaching values of 1 V/m. The observed dips in the field strengths seen going to and coming from the top of NCAR are caused by shadowing (non-LOS

path) of Eldorado Mountain by Shanahan Hill (also called Shanahan Ridge) on this

portion of the route.

Figure 56 shows the calculated E-field strengths for the Table Mountain NRQZ. Upon

comparing the measured (see figure 12) and modeled results, excellent agreement is demonstrated. Both the measured and predicted results show field strengths of about

0.2 V/m. Most of the locations at the Table Mountain NRQZ have a LOS path to the

Eldorado transmitter, which results in the relatively small variations in the measured field

strengths and in the almost constant value of the modeled data. The dips seen in both

results correspond to one location at the Table Mountain NRQZ where a non-LOS path is present. Both the measured and modeled field strengths for a transmitter on Eldorado

Mountain show that all locations on the Table Mountain NRQZ exceed the FCC

regulatory limits given in table 2.

Figure 57 shows the calculated E-field strengths for the DOC Laboratories. Upon

comparing the measured (see figure 11) and modeled results, excellent agreement is demonstrated. E-field strengths between 0.5 V/m and 1 V/m are observed. The roads on

this site are surrounded by buildings. This is reflected in the measured data and is highlighted in figure 11. The decrease in field strengths seen in the measured data due to building blockage of the signal is not apparent in the modeled data since the ITM

prediction model does not take buildings into account in the calculations. There are a few

locations on the site where non-LOS paths are present due to shadowing caused by

26
Shanahan Hill and Table Mesa. At the shadowed location (or non-LOS location) both the

measured and modeled results give the same field strength of about 0.05 V/m. Both these

results show that the outside field strengths at the DOC Laboratories will be close to 0.5 V/m to 1 V/m, which can possibly jeopardize the sensitive measurements that are performed on the site, see Section 8.

The Squaw Mountain transmitter location was analyzed next. Using a 1 MW EIRP with

the same transmitter and receiver antenna heights used in the measurements, the E-field

strengths for a transmitter located on Squaw Mountain were calculated. Contour plots of

E-field strengths for the Boulder-Denver area for 533 MHz for both a horizontally and

vertically polarized transmitting antenna are shown in figures 58 and 59, respectively.

Figures 60 and 61 show the contour plots of E-field strengths for the Boulder-Denver

area for 772 MHz for both a horizontally and vertically polarized transmitting antenna,

respectively. Once again the different colors correspond to different E-field strengths.

Figure 62 shows the calculated E-field strengths for the Table Mountain NRQZ for the

transmitter located at Squaw Mountain. Upon comparing the measured E-field strengths

(see figure 32) and modeled results, good agreement is demonstrated. Both the measured

and predicted results show field strengths of about 1 mV/m to 3 mV/m. Both the

measured and modeled results show that field strengths for all locations on the Table

Mountain NRQZ are below the FCC regulatory limits, given in table 2. Thus, the

measured and modeled data show that for Squaw Mountain, a transmitter antenna height

of 8.2 m (26.91 ft) does not violate the Table Mountain NRQZ. Predicted field strengths

for the actual proposed antenna heights are discussed in the next section.

There are a few situations where the measured and modeled results do not agree very

well. This occurs in deep shadow regions. The reason why the ITM fails to correctly

predict the field in deep shadow regions is explained as follows. The ITM (or any

irregular terrain model for that matter) is considered a quasi-two-dimensional model.

This means that irregular terrain models use only the terrain profile for the bearing

between the transmitter and receiver. Terrain features and objects that would scatter and/or reflect radio waves that are not on the bearing are not used in the calculation of the

field strengths. It is possible that in a deeply shadowed location, the majority of the

energy reaching the receiver is firom scattering and reflections from objects off of the

bearing direction (i.e., mountains, hills, buildings, cars, etc.). In such a deep fade region,

the ITM field strength calculations are based only on a diffracted path. Thus, accounting

for only the diffracted path and neglecting the other paths results in errors in field

strength predictions.

This point is illustrated in figures 63 and 64. These figures show the predicted field

strengths for a transmitter location on Squaw Mountain for the McCaslin route and the

Boulder-to-Golden route. By comparing these figures to the experimental results

presented in figures 36 and 35, respectively, it is seen that for the moderate shadow

regions the measured and modeled E-field strengths are similar. For the deep shadow

region the two results differ. The modeled results predict lower field strengths than those

firom the measured data.

27
For the McCaslin route, strong signal strengths are observed in the middle part of the

route, and as the route turns back towards the Flatirons, deep shadowing regions are observed. For the Boulder-to-Golden route, strong signal strengths are observed on

Indiana Avenue. However, once the route turns back to Highway 93, deep shadowing is observed in both results. This difference is due to the fact that the ITM does not take into

account the full three-dimensional terrain features, and as a result, it underestimates the

field strengths.

Once again, this situation only occurs in deep shadow regions. Figures 53, 54, and 62

show that for moderate shadow regions (the Table Mountain NRQZ and the Broadway

route), the ITM predictions compare very well to the measured values, illustrating the

accuracy of the ITM for moderate shadow regions. In any event, ITM predictions are conservative, since in deep shadow locations the predicted field strengths are less than

those that were measured.

5. PREDICTED E-FIELD STRENGTHS FOR THE PROPOSED

TOWER HEIGHTS

The previous section demonstrated that the ITM model can accurately (except in deep

shadow regions, as explained above) predict field strengths for both LOS and non-LOS

locations for a given antenna height. Therefore, this model was used with confidence to calculate and predict field strengths for the actual proposed antenna heights for both the

Eldorado Mountain and Squaw Mountain sites.

Figures 65 and 66 show contour plots of the E-field strengths for the Boulder-Denver

area for a transmitter located at Eldorado Mountain for 533 MHz and 772 MHz,

respectively. The results in these figures are for horizontal polarization with a transmitter

antenna height of 116 m (379 ft), and a receiver height of 2 m (6.6 ft). Figure 67 shows

the E-field strengths at the Table Mountain NRQZ for 533 MHz and 772 MHz. From this

figure it is seen that for the Table Mountain NRQZ, the predicted field strengths are about

0.2 V/m. This value, based upon transmission from Eldorado Mountain, exceeds the FCC

regulatory limit by about an order of magnitude (or by about a factor of ten in E-field

strength). This level of excess would thus jeopardize the research at the Table Mountain

NRQZ.

Figure 68 shows the E-field strengths at the DOC Laboratories for 533 MHz and

772 MHz. From this figure it is seen that for the DOC Laboratories, the predicted field

strengths approach 0.5 V/m to 1 V/m at various locations. These field strengths are high

enough to affect some of the sensitive measurements performed on a routine basis at the

DOC Laboratories, see Section 8.

The Squaw Mountain site is analyzed next. Figures 69 and 70 show contour plots of the

E-field strengths for the Boulder-Denver area for a transmitter located at Squaw

Mountain for 533 MHz and 772 MHz, respectively. The results in these figures are for

horizontal polari2:ations with a transmitter antenna height of 60.96 m (2(K) ft), and a

receiver height of 2 m (6.56 ft). Figure 71 shows the field strengths at the Table

28
Mountain NRQZ for 533 MHz and 772 MHz. The difference in field strengths for the

two frequencies is due to the fact that the amplitude of the diffracted wave decreases with

increasing frequency. From this figure it is seen that for the Table Mountain NRQZ, the

predicted field strengths are about 0.1 mV/m to 0.2 mV/m. These field strengths are well

within the FCC Table Mountain NRQZ regulatory limits. Thus, a transmitter can be

located at Squaw Mountain without violating the FCC regulatory limits or jeopardizing

the research efforts at the Table Mountain NRQZ.

Even though the DTV frequency allocation is in the 400 MHz to 700 MHz band, there is the possibility that broadcasters could decide to broadcast DTV signals at their currently

assigned NTSC frequencies [29]. This means that some DTV transmissions could be

below 400 MHz. Since propagation loss can decrease with frequency, it is important to calculate field strengths that would result from broadcasting at the lower NTSC

frequencies. Field strengths were calculated at 54 MHz (the lowest NTSC frequency) at the Table Mountain NRQZ and at the DOC Laboratories with the transmitter on Eldorado

Mountain and Squaw Mountain. These results are shown in figures 67, 68, and 71. In figure 67, it is seen that the 54 MHz results are very similar to the 533 MHz and 772

MEiz results for a transmitter on Eldorado Mountain. The similarity in the results for all three frequencies is due to the fact that the Table Mountain NRQZ is LOS from Eldorado

Mountain. For a transmitter on Eldorado Mountain, the E-field strengths for all three

frequencies exceed the FCC limit. In figure 71 (transmitter on Squaw Mountain), it is seen that the 54 MHz field strengths are somewhat larger than those at the other two

frequencies (due to diffraction effects). As seen in table 2, the FCC NRQZ limit is smaller for 54 MHz. The predicted E-field strengths for a transmitter on Squaw Mountain

at 54 MHz do exceed this FCC limit.

Here again, the data presented in this section are for an EIRP of 1 MW. Since some DTV

broadcasters have received allocations to transmit at 1.64 MW (see table 1), predicted

field strengths for 1.64 MW are needed. The E-field presented here can be converted to a

1.64 MW EIRP level by multiplying the results in all the figures by a factor of 1.3,

resulting in even higher E-field strengths than those presented here. This would result in even greater E-field strengths in the Boulder-Denver area, and would cause even greater

interference at both of the DOC facilities due to a transmitter located on the Eldorado

Mountain site.

6. DTV E-FIELD STRENGTH REQUIREMENT

Measured and modeled results to this point have assumed either a 2 m (6.6 ft) or 2.95 m

(9.68 ft) receiving antenna height. Designs of tower locations and power requirements

are based on the FCC's 9.14 m (30 ft) receiver antenna height assumption. For acceptable

DTV reception, the FCC has recommended a minimum E-field strength of 41 dB^iV/m

(0.11 mV/m) at a 9.14 m (30 ft) receiver antenna height [1]. The ITM prediction model

can be used to determine at what locations in the Boulder-Denver area the 41 dBjiV/m

field strengths for a 9.14 m (30 ft) receiving antenna height can be achieved for given

tower locations.

29
Figures 72 and 73 show the contour plot of the predicted field strengths for the BoulderDenver area for a transniitter located at Eldorado Mountain for frequencies of 533 MHz

and 772 MHz, respectively. These results were calculated for a transmitter antenna

height of 116 m (379 ft), a receiver height of 9.14 m (30 ft), and 1 MW EIRP. Figures 74

and 75 show the contour plots of the predicted field strengths for the Boulder-Denver

area for a transmitter located on Squaw Mountain for 533 MHz and 772 MHz,

respectively. These results were calculated for a transmitter antenna height of 60.96 m

(200 ft), a receiver height of 9.14 m (30 ft), and 1 MW EIEIP.

One might ask how transmitter locations would affect DTV reception. Of interest here are the locations where the 41 dBjiV/m (0.11 mV/m) FCC field strength is exceeded. If 41

dBpiV/m is exceeded, DTV reception is possible according to the FCC's assumptions.

The data shown in figures 72 through 75 are re-plotted to illustrate where the FCC's

minimum field strength is met or exceeded. These new results are shown in figures 76

through 79. In figures 76 through 79, the white areas in the plot correspond to where the

FCC's minimum field strength is exceeded. The blue shaded areas indicate areas with

field strengths that are below the FCC's minimum field strength recommendation for

DTV reception. These blue areas indicate that DTV may not be received in these areas, as indicated by the FCC's reconmaendation. Note that as far as the FCC's 41 dBp,V/m

(0.11 mV/m) recommendation is concerned, it is seen in figures 76 through 79 that

Squaw Mountain covers basically the same area as a transmitter on Eldorado Mountain,

for the purposes of DTV reception with a 9.14 m (30 ft) height fixed receiving antenna.

Based on the results in the previous section, while the Squaw Mountain site covers the

same area as the Eldorado Mountain site, the Squaw Mountain site does not violate the

regulatory field strength limits protecting the Table Mountain NRQZ. The Squaw

Mountain site would also provide additional protection to the DOC Laboratories. Note

that if a 1.64 MW EIRP is used, the 41dBp,V/m recommendation limits would extend the

DTV coverage area.

7. ANTENNA PATTERN EFFECTS

All the predicted E-field strengths presented in this report were obtained with the

assumption that the transmitting antenna was an omnidirectional antenna. The

measurement data presented here were collected with antennas with moderate antenna

patterns, i.e., a 1.9 dBi omni-azimuthal directional antenna on the Eldorado Mountain site and a 6.5 dBi log-periodic antenna on the Squaw Mountain site. The actual antennas that

will be used for the proposed tower will have some type of antenna pattern associated

with them. The ITM propagation model presented here has a capability of using any

transmitter antenna pattern in the prediction. Unfortunately, at this time we do not have

information on the antenna patterns. At a later date, when and if such antenna patterns are available, new predicted E-field strengths will be calculated.

With this noted, the results in this report can still be used once the actual antenna patterns are known, as explained in the following. When LOS propagation conditions are present,

the simple free-space calculation given in equation (2) can be used to determine the Efield strengths without the need to resort to the ITM prediction model. LOS situations

30
occur for the Eldorado Mountain site for the Boulder area. For a transmitter location on

Eldorado Mountain, many locations throughout the Boulder area (including the DOC

Laboratories and the Table Mountain NRQZ) exhibit LOS paths. The ability of the

simple free-space calculation given in equation (2) to predict E-field strengths in a LOS

situation is illustrated in figures 11 and 12. These figures show the measured E-field

strengths for a transmitter located on Eldorado Mountain for the DOC Laboratories and

the Table Mountain NRQZ. Notice that the free-space calculation correlates very well

with the measured data. There is some variability in the measured data, due to multipath

effects that the free-space model cannot account for, but typical E-field strengths at both

sites are very well accounted for with the free-space model.

Thus, once the actual antenna patterns are known, the EIRP in any direction can be

obtained, and equation (2) can be used to estimate the E-field strengths in the LOS

situation. An alternative approach is to simply scale the results in this report by the

appropriate EIRP for an antenna at a given location and a given direction. From the

results in figure 12, it is seen that, for a transmitter on Eldorado Mountain, a reduction of

23 dB in either the transmitter power level or in the antenna gain is needed to achieve the

FCC NRQZ limit.

8. EFFECTS OF BROADBAND TRANSMISSION ON

SENSITIVE MEASUREMENTS

Historically, the radio science programs in the former National Bureau of Standards

(those programs are now in NIST and ITS) drove the need to establish a field site remote

from their Washington, DC, laboratories. Boulder was chosen over several contenders

because of the relatively quiet, radio-fii^uency electromagnetic environment, which

would allow for more accurate measurements and experiments; the varied geographic

terrain, which would facilitate the study of radio propagation; and the presence of a major

university (the University of Colorado) as well as the proximity of a large city (Denver).

The technical mission of the Boulder labs was to develop the most accurate possible

reference standards and calibration services to insure compatibility of the emerging radio,

microwave, and radar technologies that the nation was then developing. Radio

propagation research was fundamental to this work, and as higher frequencies were

explored, the interactions between electromagnetic waves and atmospheric layers led to new directions of research. This work was, and continues to be, fundamental to all of the

advances made in radio-frequency technology. NIST's research on accurate measurement

systems, and its development of standards and calibration services for the Nation, play an

essential role in making possible the technologies that we use daily such as wireless

conmiunication, high-speed digital technology, time-and-frequency synchronization,

satellite conmiunications, radar, and optical fiber communications links, to name only a

few.

Radio research projects performed outdoors often require that receivers be constructed to receive wideband signals. Furthermore, those receivers must often be constructed with

high performance, low noise amplifiers (LNAs) in the so-called front-end, just after the

receive antenna. The requirement for wide bandwidth means that such receivers integrate

31
the total energy across a wide part of the spectrum. The LNAs used in those front ends

are susceptible to nonlinear effects due to the integration of large amounts of energy

across wide portions of spectrum. This effect has been documented in Reference [30].

Simply put, a wideband radio receiver with a sensitive amplifier in the front end will

experience a condition known as overload in the presence of strong signals that are not

only present at the desired frequency, but that are also substantially off-tuned from the

center frequency. Overload of LNAs can occur in the presence of strong signals even if those signals are as much as a few hundred megahertz off the receiver's center frequency

[30]. When an LNA goes into an overload condition, its gain is greatly reduced. The

result is loss of the desired signal or signals.

Because of the Government's need to be able to perform radio research in outdoor

locations with wideband, sensitive receivers, the only practical and general technical

solution is to limit the total power originating from local signal sources. The limitation

must be adequate to ensure that the cumulative (integrated) amount of energy mat is coupled into the sensitive front end amplifiers from all local signals is low enough not to overload the receiver front ends. This is one requirement that has caused the Federal

Government to create and maintain the Table Mountain NRQZ.

The grandfathered signal levels of television channels 4, 6, 7, and 9 provide an example

of the difficulties that high signal sfrengths within the NRQZ produce for sensitive radio

measurement systems. These grandfathered signal levels within the NRQZ range from

about 3 dB above the limit to as much as 13 dB above the limit. When the spectrum

survey in this report was performed, it was necessary to insert 10 dB of attenuation into

the measurement system's front end to prevent overload by these television signals. That

is, the sensitivity of the entire measurement system had to be degraded by 10 dB to prevent saturation due to these signals. This attenuation had to be inserted for all measurements in the television bands between 50 MHz and 88 MHz (due to strong Efields from channels 4 and 6), and also between 170 MHz and 220 MHz (due to E-fields

from channels 7 and 9). Signal strengths below the NRQZ limits usually require no

attenuation in the receiver system front end, and enable more sensitive and more accurate

measurements.

Similar measurement degradation will impair the usefulness of measurements and

experiments in other bands, to the extent that signals in those bands exceed the NRQZ

limits. Mobile signals that exceed the NRQZ limits may provide some technical

opportunities for ameliorative work-arounds, but broadcast signals that are effectively

present on a continuous basis do not allow such work-arounds. Receivers in those bands

are permanentiy impaired by the incident signals, as happened for the horizontally

polarized spectrum survey measurements described above. This integrating effect of

several frequencies transmitting simultaneously has adverse effects on several types of

research measurement efforts that occur at both the Table Mountain NRQZ and at the

DOC Laboratories.

There are no Federal, state, or local laws or regulations, corresponding to the NRQZ

restrictions, that protect the DOC Laboratories. However, the level of EM-field emissions

from the proposed towers may be high enough on-site to compromise some experimental

32
and metrological programs. The E-field strengths from a single station transmitting at 1 MW EIRP from Eldorado Mountain will result in 0.5 V/m to 1 V/m over the entire site. To date, six stations have been given permission to operate at 1.6 MW EIRP, which,

upon scaling the results above to the 1.6 MW EIRP level, results in an E-field-strength

on-site of 0.6 V/m to 1.3 V/m. Furthermore, the potential tower operators are soliciting

existing TV and FM stations to move their transmitters to the Eldorado Mountain site. Such a concentration of transmitters will have a more adverse effect because of the even

broader spectral coverage. Cutting-edge physics, metrology, and radio research

conducted at the DOC Laboratories for the benefit of industry and the Nation could be

compromised. Some examples of programs sensitive to electromagnetic fields are given

below.

The research and antenna calibrations conducted at the NIST Open Area Test Site

(OATS) groundscreen facility is critical for support of a very broad cross section of

industry. Literally the entire U.S. electronics industry, including all manufacturers of

computer and information technology, coromunications equipment, medical electronic

equipment, electronic test equipment, television and other electronic entertainment

equipment, certain appliances, industrial equipment, and many other categories, must test their product's conformity to national and international standards. To be recognized,

these tests must be traceable to NIST, and the standards themselves are developed in an

intemational forum with NIST providing the technical expertise and experimental

validation to advance the cause of U.S. industry. All tests and calibrations, and

experimental research performed on the groundscreen are performed from 30 MHz to

1 GHz, and the DTV bands will cover a significant portion of this band (476 MHz to 698 MHz). The comparatively strong field strengths from the DTV towers (on Eldorado

Mountain) will Hterally override the signals that NIST generates and uses in its calibrations and experiments. Furthermore, the broad nature of the signals is such that it will not be possible to shift to an adjacent null in the spectrum and obtain an approximate

measurement. NIST research that supports ANSI, ITI, lEC/CISPR, as well as a broad

cross section of industry, will be compromised.

Interference problems with DTV signals are currently being experienced by commercial

electromagnetic compatibility (EMC) laboratories where EMC measurements and

calibrations are performed routinely at other OATS facihties, as indicated by Roland

Gubisch [31], the vice-chair of the United States Council of EMC Laboratories (USCEL).

USCEL was developed to aid U.S. industry with EMC standards and testing procedures.

Gubisch indicated [31] that DTV signals have had adverse effects on an OATS in the

Boston, Massachusetts, area. At this OATS and other sites, field strengths as low as 0.0002 V/m (46 dB^V/m) have interfered with tests. The 0.0002 V/m is the FCC radiated

emission limit for unintentional radiators [32]. The DTV signals act as 6 MHz wideband

noise in the 500 MHz to 700 MHz frequency range, hindering the ability to test and

certify electronic products on these outdoor sites. The broadband noise nature of the

6 MHz DTV signals can be seen in the 2001 spectrum survey for the DTV Channel 32

(578 MHz to 584 MHz) transmission, see figure A.41. In fact, Gubisch has informed

NIST that USCEL members have experienced problems on outdoor facilities when DTV

E-field levels are even lower than 0.0002 V/m. The broad 6 MHz signals from each

station and the even broader spectrum saturation from strings of adjacent channels are

33
preventing EMC test laboratories from making measurements in outdoor facilities that are prescribed by international standards. This is forcing commercial labs to use much

more costly and potentially less accurate special indoor facilities such as semi-anechoic

chambers. However, NIST as the national standards laboratory that provides the basis for

and harmonization of all national measurements, must maintain the smallest uncertainties

possible in its measurements.

Other examples of the types of interference that would be experienced at the DOC

Laboratories are as follows. In order to simulate potential effects of instrumentation of

the proposed DTV towers on Eldorado Mountain, experiments were performed in two

different laboratories at NIST. In these experiments E-field strengths of 0.1 V/m,

0.5 V/m, and 1.0 V/m (the values that would be present at the DOC Laboratories as discussed above) were generated in two different research laboratories. The first laboratory was in the Optoelectronics Division, the Sources and Detectors Group. This

group is developing standards and measurement systems for optical intensity noise of

laser transmitters and optical fiber amplifiers used in optical communications systems.

These consist of both laboratory and transfer standards. In the study, E-field strengths of

0.1 V/m, 0.5 V/m, and 1.0 V/m were radiated onto optical noise instrumentation at frequencies of 400 MHz to 700 MHz. This frequency range falls within the broad

frequency range of interest for noise studies, which presently is 100 MHz to 4.1 GHz and

higher. For field strengths of 0.1 V/m, the noise floor of the instrumentation rose between 7 dBm/Hz and 10 dBm/Hz within this frequency range, a significant amount. At

field strengths of 0.5 V/m the noise floor rose by 15 dBm/Hz to 33 dBm/Hz, a large and

disturbing amount. At field strengths of 1 V/m the noise floor rose by 22 dBm/Hz to 43 dBm/Hz, a significant amount. Without additional shielding of the affected

equipment, the resultant increase in the noise floor would prevent NIST from performing

low intensity noise measurements, in this frequency range, that are important in noise

studies. Presently, it is not known how well additional shielding would diminish this

problem. Such a result can only be determined experimentally.

The second experiment was performed in the Time and Frequency Division of NIST. lii this division, the Atomic Standards Group, Network Synchronization Group, and Time

and Frequency Service Group use GPS signals for the following: (1) to contribute the

NIST clock (frequency standards) data to the computation of TAI (International Atomic

Time) and UTC (Coordinated Universal Time), (2) to compare UTC as realized at NIST,

to the frequency standards of other remote laboratories (such as the U.S. Naval

Observatory, the National Physical Laboratory of the United Kingdom, the PhysikalischTechnische Bundesanstalt in Braunschweig, Germany, etc.), and (3) to provide time and

frequency dissemination/calibration service to industry and research institutions. In the

study, E-field stirengths of 0.1 V/m and 0.5 V/m at 613.8 MHz and 787.7 MHz were

incident onto the antennas for three different types of GPS receivers. The antennas were

located on the roof of the main building at the DOC Laboratories, see figure 80. This

figure also illustrates the LOS path that would be present from the Eldorado Mountain

tower site. These two frequencies correspond to the first subharmonic of the GPS L2

(1227.6 MHz) and GPS LI (1575.42 MHz) frequencies. Due to nonlinearity effects of the

GPS receiver's LNA (low noise amplifier), the 613.8 MHz and 787.5 MHz signals at 0.5

V/m saturated the front end of the GPS receiver, resulting in loss of GPS signal lock by

34
the receiver. When the second harmonics of these frequencies were greater than

-136 dBm as received by the GPS antennas, the receiver could not lock on the GPS

signal. Once the E-field strength was reduced to 0.1 V/m the receiver was able to lock on

the GPS signal.

The above examples represent only a sample of possible and likely negative effects of

higher levels of ambient electromagnetic fields in this frequency range on DOC

Laboratory programs in the Boulder, Colorado, area. Other technical programs at NIST,

as well as NOAA and ITS programs, may also be impacted.

9. SUMMARY AND CONCLUSION

In this report, we have analyzed the expected E-field strengths in the Boulder area from

two proposed terrestrial DTV transmitter locations, the Eldorado Mountain site and the

Squaw Mountain site. The Eldorado Mountain and Squaw Mountain sites were chosen in

this study because these two possible sites bound the propagation environment that would

occur at both the Table Mountain NRQZ and the DOC Laboratories. The Eldorado

Mountain site affords substantial Hne-of-sight coverage over the Boulder area, and the

Squaw Mountain site affords only indirect (diffractive) coverage over the same area. The

other possible tower sites fall between these two types of propagation conditions. The

proposed transmitter tower heights for the two sites were obtained from either the

landowners or public documents.

In this analysis, measurements of the E-field strengths for a transmitter located at each of

these sites were performed. These measured data were then compared to predicted Efield strengths obtained from the ITS ITM propagation model. The predicted field

strengths from the two transmitter locations matched well with measured strengths from

those locations at frequencies near both ends of the existing UHF television band. This

indicates that the ITM predictions are reliable, and can be used with confidence in

predicting the strengths that might be received at any given location in the area (with the

exception of very deep shadowed regions) for any given transmitter and receiver heights.

The ITS ITM propagation model was then used to predict the E-field strengths in the

Boulder area for the actual proposed transmitter antenna heights of two possible

transmitter locations, Eldorado Mountain and Squaw Mountain. The E-field strengths were calculated based on 1.0 MW EIRP. Once the E-field strengths are obtained for 1.0

MW EIRP, the E-field strengths can be scaled to any desired transmitter power level.

With these predictions, we were able to determine the E-field strengths at both the DOC

Laboratories and at the Table Mountain NRQZ. The results presented here show that at the Table Mountain NRQZ, the predicted E-field strengths are about 0.3 V/m for a

transmitter on Eldorado Mountain at 1.0 MW EIRP. This number exceeds the FCC's

regulatory (47 CFR 73.1030) limit by about an order of magnitude. At that level, the

research at the Table Mountain NRQZ will be compromised. The results also show that

the E-field strengths at the DOC Laboratories for a transmitter located on Eldorado

Mountain are about 1 V/m for 1.0 MW EIRP. These field strengths are high enough to possibly jeopardize the sensitive measurements done on a routine basis at the DOC

Laboratories, as discussed in Section 8. On the other hand, the results presented here

35
show that at the Table Mountain NRQZ, the predicted E-field strengths are about

0.002 V/m for a transnaitter located on Squaw Mountain for 1.0 MW EIRP. These field

strengths are well within the FCC's Table Mountain NRQZ regulatory (47 CFR 73.1030)

limit. Thus, the results presented here indicate that a transmitter could be located at Squaw Mountain without violating the FCC's regulatory limit or jeopardizing the

research efforts at the Table Mountain NRQZ.

As discussed above, the measured and modeled data presented in this report are for an EIRP of 1 MW. As indicated in table 1, some of the DTV channels have maximum

power allocations of 1.64 MW EIRP. The E-field strengths presented here can be

transformed to a 1.64 MW EIRP by multiplying the data shown in all the figures by a

factor of 1.3 (which would increase the E-field strengths by 30 %). This would result in even higher E-field strengths in the Boulder-Denver area than those presented here, and

would cause even greater interference at both the DOC facilities due to a transmitter

located on the Eldorado Mountain site. After scaling the results in this report to the

current maximum EIRP levels (1.64 MW EIRP), the E-field strengths at both the Table

Mountain NRQZ and DOC Laboratories can be determined for this maximum transmitter

power level. The E-field strengths at the Table Mountain NRQZ would be about 0.4 V/m

for a transmitter on Eldorado Mountain with 1.64 MW EIRP, and the E-field strengths at the DOC Laboratories would be about 1.3 V/m for 1.64 MW EIRP. In Reference [1],

the FCC indicates that in the future, adjustments to the allocated power levels may be

granted under some situations, in order to allow power levels higher than 1.64 MW. The

FNPRM [5] indicated maximum ERP of 5 MW (or 8.2 MW EIRP). If these high power

levels are granted, the result would be even higher E-field strengths in the BoulderDenver area than those presented here.

In this report we also present data from a recent spectrum survey of the Table Mountain

NRQZ. The results of this spectrum survey indicate that at the time of the survey (late

1998 and April 2001) the requirements of 47 CFR 73.1030 were being met by applicable

signals at the Table Mountain NRQZ. The site therefore continues to be a useful and

necessary location for present and future radio experiments. We also present results of a spectrum survey performed at the DOC Laboratories, illustrating a generally low level of

ambient electromagnetic fields.

For DTV reception, the FCC specifies a minimum E-field strength of 41 dB|iV/m

(0.11 mV/m) for a receiver antenna at a height of 9.14 m (30 ft). Using the ITM

prediction model, we also predicted the coverage areas where the FCC's minimum field

strength for acceptable reception is met or exceeded. From the results shown here, it is seen that the two proposed transmitter locations (Eldorado Mountain and Squaw

Mountain) have basically the same DTV coverage areas. However, the data in these

results show that a transmitter on Squaw Mountain will not violate the FCC regulatory

limits protecting the Table Mountain NRQZ.

The models and measurements discussed in this report can aid in determining whether the

minimum field strength requirement of 41 dB|AV/m can be achieved at various locations.

However, another very important consideration for DTV (and any digital communication

system, for that matter) is multipath effects. Multipath effects result in bit error rates

36
(BER), or data error, in digital systems [33-39]. These effects can and do occur with

DTV. The multipath issue is not isolated to the outdoor propagation environment. The

multipath effects for an indoor propagation environment (i.e., a signal propagating to a TV antenna inside a house) can be equal or more critical [6, 40-44]. The indoor multipath

issue is confronted in the following manner. In laying out the recommendations for DTV

system designs (i.e., the Advanced Television Systems Committee (ATSC)

standardization process), receiving antennas were assumed to be located on the outside of

homes at an antenna height of 9.14 m (30 ft). However, this may not be possible for one

reason or another (e.g., some communities have ordinances or covenants against external

TV antennas). As a result, receiving antennas may be placed inside homes, either on top

of TV sets or in attics. DTV signals propagating into homes will reflect off of surfaces

and objects in the home, resulting in substantial multipath. This indoor multipath issue can have an adverse effect on the quality of service for DTV systems. More detailed

studies are needed in order to determine whether the multipath environment from the two

proposed sites is substantially different in order to assess the ultimate location of the

antenna towers. Such a study can help in the assessments of the DTV receiver standards,

in order to determine whether the indoor and outdoor multipath problem will affect the

quality of service of terrestrial DTV systems and affect terrestrial DTV proliferation in

the marketplace. This is important because of the issue of the encumbrances on the

analog spectrum (i.e., channels 52 through 69), which are scheduled to be returned for

other uses at the end of the DTV transition.

Furthermore, in a recent report [6], the ATSC Task Force has discussed the indoor DTV

reception problem. This report includes reviews of the results of recent field tests of DTV

reception in and around several major metropolitan areas in North and South America.

For example, in the Washington, DC-Baltimore, Maryland, metroplex, it notes that DTV

reception success fell from 75 % (on average) of all outdoor antenna sites with 9.14 m

(30 ft) antennas to 32 % of all indoor antenna sites. (The indoor sites were preferentially

chosen for adequate DTV electric field strengths outdoors, at the 9.14 m antenna height.)

A considerable portion of the report is devoted to a discussion of potential improvements

in DTV receiver and antenna technologies that would be likely to enhance DTV reception

with indoor (and outdoor) antennas. Short of these improvements, the report lays out two

possible options to improve indoor reception. The first option would be to lower the

maximum data rate. The second option would be to increase the E-field strengths to make

indoor reception more robust, by increasing DTV transmitters' ERPs. The ATSC report

suggests that in order to overcome the indoor antenna problem, field strengths at the 9.14

m (30 ft) reference height may need to be increased substantially to 97 dBp,V/m. This is an increase of 56 dB over the FCC's 41 dB^iV/m, which is a factor of approximately 631

in field strength. This 56 dB increase can be obtained by either substantially reducing the

coverage area of DTV reception or by increasing the power by 56 dB, clearly an

unrealistic scenario. Obviously, if transmitter power levels are increased to compensate

for the indoor problem, higher E-field strengths than those presented in this report could

occur at both the DOC Laboratories and at the Table Mountain NRQZ, as well as at other

areas throughout Boulder.

The studies in this report were carried out for two individual frequencies. In reality the

DTV transmitter tower will have systems transmitting simultaneously over the entire

37
band of frequencies shown in table 1, As discussed in this report, because of the way

systems respond to a broad band of frequencies, a cumulative (integrated effect) amount

of energy can couple into a system and adversely affect the sensitivity of a measurement,

thereby potentially jeopardizing the quality of research performed at the DOC

Laboratories. The data presented in this report illustrate that E-field strengths on the

order of 1 V/m could be present at the DOC Laboratories. The studies presented in

Section 8 illustrate only a few of the potential problems that may be experienced at the

DOC laboratories.

While the results presented in this report are for omnidirectional or omni-azimuthal

directional antenna patterns, they will remain relevant once the actual antenna pattems

are known. For LOS propagation, the simple free-space calculation given in equation (2) can be used to determine the E-field strengths without the need to resort to the ITM

prediction model. LOS propagation conditions occur for the Eldorado Mountain site for

the Boulder area (including the DOC Laboratories and the Table Mountain NRQZ).

Therefore, once the actual antenna pattems are known, the EDRP in any direction can be

obtained, and equation (2) can be used to estimate the E-field strengths in LOS situations.

An alternative approach is to simply scale the results in this report by the appropriate

EIRP for an antenna at a given location. With this noted, the results in this report are valid for estimating the E-field strengths in the Boulder-Denver area. If additional results are needed for a given transmitting antenna pattern at a specific location, the ITM could

be used for such analysis at a future date.

38
10. REFERENCES

[1] Advanced television systems and their impact upon the existing television

broadcast service. Sixth Report and Order, Federal Communications Commission,

FCC 97-115, MM Docket No. 87-268; April 1997.

[2] Report of National Television System Committee. National Television System

Committee; 1953.

[3] Fink, D.C. Color television standards: Selected papers and records. New York:

McGraw-Hill; 1971.

[4] Code of Federal Regulations, Title 47: Telecommunication, Part 2: Frequency

allocations and radio treaty matters; General rules and regulations, Subpart A:

Terminology. Part 2.1 Terms and Definitions. Office of the Federal Register,

National Archives and Records Administration, p. 330; October 1, 2000.

[5] Advanced television systems and their impact upon the existing television

broadcast services. Sixth Further Notice of Proposed Rule Making, Federal

Communications Commission, MM Docket No. 87-268; August 14, 1996.

[6] Performance assessment of the ATSC transmission system, equipment and future

directions. Report of the ATSC Task Force on RF System Performance; April 12,

2001. http://www.atsc.org (April 20, 2001).

[7] Annual assessment of the status of competition in the market for the delivery of

video programming. Seventh Annual Report, Federal Communications

Commission, CS Docket No. 00-132; January 8, 2001.

[8] Code of Federal Regulations, Title 47, Chapter I: Federal Communications

Commission: Telecommunication. Section 73.1030: Notifications concerning

interference to radio astronomy, research and receiving installations. Office of the

Federal Register, National Archives and Records Administration, pp. 279-280,

October 1, 2000.

[9] Manual of regulations and procedures for federal radio frequency management.

National Telecommunications and Information Administration, January 2000

edition with May/September 2000 revisions, pp. 8-43 to 8^5; 2000.

[10] Telecommunication Research Facilities of the United States, Colorado Revised

Statutes, vol. 11, chap. 97. Permanent Cumulative Supplement, Article 26,

Sections 36-26-1 to 36-26-5; 106-2-35 and 139-60-11; 1969.

[11] Balanis, C.A. Antenna theory: Analysis and design. New York: John Wiley &

Sons, Inc.; 1997.

39
[12] Friss, H.T, A note on a simple transmission fonnula, Proc. IRE, 34: 254-256;

1946.

[13] Maclean, T.S.M.; Wu, Z. Radiowave propagation over ground. London: Chapman

& Hall; 1993.

[14] Shibuya, S. A basic atlas of radio-wave propagation. New York: John Wiley &

Sons, Inc.; 1987.

[15] IEEE standard for safety levels with respect to human exposure to radio frequency

electromagnetic fields, 3 kHz to 300 GHz. IEEE C95. 1-1991; April 27, 1992.

[16] Polk C; Postow, E. CRC handbook of biological effects of electromagnetic fields.

Boca Raton, FL: CRC Press, Inc.; 1986.

[17] Janaswamy, R. Radiowave propagation and smart antennas for wireless

communication. Boston, MA: Kluwer Academic Publishers; 2001.

[18] Adawi, N.S.; Bertoni, H.L.; Child, J.R.; Danial, W.A.; Detra, J.E.; Eckert, R.P.;

Flath, E.H.; Forrest, R.T.; Lee, W.C.Y.; McConoughery, S.R.; Murray, P.J.; Sachs, H.; Schrenk, G.L.; Shepherd, N.H.; Shipley, FX). Coverage prediction for

mobile radio systems operating in the 800/900 MHz frequency range. JEEE

Trans. Vehicular Technol., 37(1): 3-75; 1988.

[19] Blaunstein, N. Radio propagation in cellular networks. Boston, MA: Artech

House; 2000.

[20] Hufford, G.A.; Longley, A.G.; Kissick, W.A. A guide to the use of the ITS

irregular terrain model in the area prediction mode. NTIA Report 82-100: April

1982.

[21] Longley A.G.; Rice, P.L. Prediction of tropospheric radio transmission loss over

irregular terrain: A computer method-1968. ESSA Technical Report ERL 79-ITS67; July 1968.

[22] Sanders F.H.; Lawrence, V.S. Broadband spectrum survey at Denver, Colorado.

NTIA Report 95-321; September 1995.

[23] Sanders, F.H.; Ramsey, B.J.; Lawrence, V.S. Broadband spectrum survey at San

Diego, California. NTIA Report 97-334; December 1996.

[24] Sanders, F.H.; Ramsey, B.J.; Lawrence, V.S. Broadband spectrum survey at Los

Angeles, California. NTIA Report 97-336; May 1997.

[25] Sanders, F.H.; Ramsey, B.J.; Lawrence, V.S. Broadband spectrum survey at San

Francisco, California May-June 1995. NTIA Report 99-367; July 1999.

40
[26] The temporal and spectral characteristics of ultrawideband signals, Kissick, W.A.,

ed. NTIA Report 01-383; January 2001, Appendix C.

[27]- Jakes, W.C. Microwave mobile communications. New York: IEEE Press; 1974.

[28] Steele, R. Mobile radio communications. New York: IEEE Press; 1992.

[29] Review of the Commission's rules and policies affecting the conversion to digital

television. Report and Order, Federal Conmiunications Commission, FCC 01-24,

MM Docket No. 00-39; January 2001.

[30] Sanders, F.H.; Hinkle, R.L.; Ramsey, B.J.; Analysis of compatibility between

radar stations and 4 GHz fixed-satellite earth stations. NTIA Report 94-313; July

1999.

[31] Gubisch, R. Phone call and E-mail conununication, weeks of April 23-27, 2001,

andMay 7-11, 2001.

[32] Code of Federal Regulations, Title 47: Telecommunication, Section 15.109:

Radiated emission hmits. Office of the Federal Register, National Archives and

Records Administration, pp. 697-698; October 1, 2000.

[33] Chuang, J.C.-I. The effects of time delay spread on portable radio

communications channels with digital modulation. IEEE J. Selected Areas in

Commun., 5(5): 879-889; 1987.

[34] Macario, R.C.V. Modem personal radio systems. London: TEH; 1996.

[35] Cox, D.C. Correlation bandwidth and delay spread multipath propagation

statistics for 910 MHz urban mobile radio channels. IEEE Trans. Commun.,

23(11): 1271-1280; 1975.

[36] Jakes, W.C. An approximate method to estimate an upper bound on the effect of

multipath delay distortion on digital transmission. IEEE Trans. Commun., 27(1):

76-81; 1979.

[37] Aprille, TJ. Filtering and equalization for digital transmission. IEEE Commun.

Magazine, pp. 17-24; March 1983.

[38] Webb, W.T. Equaliser techniques for QAM transmissions over dispersive mobile

channels. lEEProc., 138(6): 566-576; 1991.

[39] Pahlavan, K.; Levesque, A.H. Wireless information networks. New York: John

Wiley & Sons, Inc.; 1998.

[40] Hufford, G. A characterization of the multipath in die HDTV channel. IEEE

Trans. Broadcasting, 38: 252-255; December 1992.

41
[41] Sari, H.; Karam, G.; Jeanclaude, I. Transmission techniques for digital terrestrial

TV broadcasting. IEEE Commun. Magazine: pp. 100-109; February 1995.

[42] Mignone, V.; Morello, A. CD3-OFDM: A novel demodulation scheme for fixed

and mobile receivers. IEEE Trans. Commun., 44: 1144-1151: September 1996.

[43] Ghosh, M. Blind decision feedback equalization for terrestrial television

receivers. Proc. IEEE: pp. 2070-2081; October 1998.

[44] Fox, B. Digital TV rollout: Has the United States got it wrong with digital

terrestrial TV. IEEE Spectrum, 38(2): 65-67; February 2001.

I

E

42
PuG,

Pr, E, or ^O)

Figure 1. Illustration of an antenna in free space.

R (Distance from Transmitter) [miles]

2 4 6 8 10 12 14 16 18

100.000 , 1 , 1

1 , 1 < 1 < 1 < 1 , 1 , 1 ,

, y US 27.5 V/m exposure guideline

10.000 \ Italian 6 V/m exposure guideline \ ,^Russia and Poland 3 V/m exposure guideline

1.000 \"-

0.100 ^30 mV/m Table Mt. Protection Limit

0.010

0.001

Distance to NRQZ from Eldorado Mtn.

'

1

1 < 1

1

1

<

1

<

1

' 1'

1 4000 8000 12000 16000 20000 24000 28000 32000

R (Distance from Transmitter) [meters]

Figure 2. Magnitude of the E-field calculated for a free-space environment as a function

ofi^foranEIRPof IMW.

43
R (Distance from Transmitter) [miles]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

lE+1 J , 1 1 1 1 M I 1 1 1 1 L 1 < 1 1 1 , 1 < M 1 1 , 1 1 L LI < —

: US2W/m exposure guide ine

lE+0 -=

lE-1

-

•4 z s - \ Distance to NRQZ from Eldorado Mtn.

lE-2 ~1

Q lE-3 -^

S

o

a. lE-4 ^ ^

lE-5

lE-6

-=

2.4 nW/m' Table Mt. Protection Limit /

' 1

' 1'

1 ' 1

'

1

' 1

' 1

'

1 4000 8000 12000 16000 20000 24000 28000 32000

R (Distance from Transmitter) [meters]

Figure 3. The power density iP calculated for a free-space environment as a function of/?

for an EIRP of 1 MW.

LOS Point

NON-LOS Point (shadowed region)

Figure 4. Illustration of a realistic propagation environment where irregular terrain

features (or profiles) are present. Both a line-of-sight (LOS) path and a non-line-of-sight

(non-LOS) path are shown.

44
Figure 5. Illustration of the RSMS with telescoping masts raised and antennas mounted

for a broadband spectrum survey such as was performed at the Table Mountain NRQZ.

45
V V w V Y

\7 V \7 (Rooftop antenna) High-Speed DF Array V7 1 1

^li. 6 Selectable Antenna Ports 6 0-70 dB RF

Attenuation ^ 6 Selectoble RF Paths

Noise Diode

I

I do

n n n n

I

(NO

I

M N

I X

•<i-o Y Y V Y V

I X

coo

Bandpass

niters and Preamps,

plus StraightThrough

Poth

V

Auxilliory Rotator

Controller /K >K

GPIB

RF line descends heavy—duty

telescoping 26-foot mast

Rotator

Controller #2

Bus

GPIB

21.4- MHz IF

RF Path

GHz

LNA

or 321.4 MHz

ICOM Demodulator

r^

Spectrum

Analyzer §2

HP-8566B

0-22 GHz

0-18

jGHZ

I Rotary

Joint

YIG Tuning Voltage

(Inverted)

GPIB

^

Digital Oscilloscope

GPIB

Pulse Analyzer/

Blanker

Modulation Analyzer

Mass

Storage

Bus

GPIB

80486-based

Controller #2

Towertop 0.5-18 GHz

Front-end Interface

I/O

Printer

I/O

Cellular Fax/Modem

Parallel

GPIB RF line descends

light-duty( telescoping 30-foot most

Bus

Rotator

Controller #1

I Manual Controll.

21.4 MHz IF or 321.4 IMHZ

RF Path

HP-85685A (0-2 GHz)

(0-50 dB RF

attenuator, varactor and YIG preselector, and preamplifier)

Spectrum

Analyzer jjll HP-8566B

0-22 GHz

GPIB

RF Path

804B6-based

Controller #1

Mass

Storage

Bus

Figure 6. Block diagram of the RSMS measurement system.

J

46

I
Transmitter Output Levels Calibrated at this Point

High Power

Amplifier

Combiner •

Signal Generator

(533 MHz

sine wave)

Transmit Antenna

30' RF Line

533 MHz

Receiver

Noise Diode

Calibrations Performed

at this Point

Signal Generator

(772 MHz

sine wave)

Transmitter

HP-85685A

Preselector

HP-8566B

Spectrum

Analyzer

Splitter

GPIB

PC Computer

(instrument

controller and

data recording)

772 MHz

Receiver

HP-85685A

Preselector

HP-8566B

Spectrum

Analyzer

PC Computer

(instrument

controller and

data recording)

Receiver

Figure 7. Block diagram of the transmitter systems on each mountaintop and the receiver

measurement system.

47
Figure 8. An annotated photograph of the transmitter system used on both mountaintops.

48
Squaw\Mt|^

Figure 9. Map of the Denver-Boulder area showing the locations of the two proposed

sites (Eldorado Mountain and Squaw Mountain) and the Table Mountain NRQZ.

49
Figure 10a. Map of the 28 Street Route and the Broadway/Highway 93 Route.

50
Figure 10b. Map of the McCaslin Loop, also showing the Greenbriar loop and NCAR.

51
Q«<rCiiws. .. 'TT ^^^^^ r^^

Figure 10c. Map of the Boulder-to-Golden route.

52
10.00

Location

Figure 11. Measured E-field levels scaled to 1 MW EIRP at the DOC Laboratories. These

results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

10.00

1.00

>

0.10

0.01

Figure 12. Measured E-field levels scaled to 1 MW EERP at the Table Mountain NRQZ.

These results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

53
10.00 ^T

1.00 —

>: 0.10 —

0.01 —

0.00

DOC to Hwy.36 on 28th Street Hwy. 36 to Table Mtn.

Location Figure 13. Measured E-field levels scaled to 1 MW EIRP from the DOC Laboratories

down 28'"^ Street to the Table Mountain NRQZ. These results are for a transmitter on

Eldorado Mountain for a frequency of 533 MHz, a transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

10.000 -^

1.000 —

0.100

0.010

0.001 Location Figure 14. Measured E-field levels scaled to 1 MW EIRP from Table Mountain NRQZ to Highway 72 via Highway 36, Broadway, and Highway 93. These results are for a

transmitter on Eldorado Mountain for a frequency of 533 MHz, a transmitter height of

3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

54
100.00 -^

Location Figure 15. Measured E-field levels scaled to 1 MW EIRP on the McCaslin loop. These

results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

10.00

1.00

Broadway to NCAR

>

0.10

0.01

Top of NCAR

NCAR to Broadway

Location T

Figure 16. Measured E-field levels scaled to 1 MW EIRP at the NCAR facility at the top

of Table Mesa. These results are for a transmitter on Eldorado Mountain for a frequency

of 533 MHz, a transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m

(9.68 ft).

55
10.000 -IT

1.000 —

0.100 —

0.010 —

0.001 Location Figure 17. Measured E-field levels scaled to 1 MW EIRP in Eldorado Canyon. These

results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, a

transmitter height of 3.66 m (12,0 ft), and a receiver height of 2.95 m (9.68 ft).

1.00

0.10

>

0.01 —

0.00 Location Figure 18. Measured E-field levels scaled to 1 MW EIRP on County Road 67. These

results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

56
10,00

1.00

>

0.10

0.01

Fairview high school Southern Hills Jr. high school

I Location Figure 19. Measured E-field levels scaled to 1 MW EIRP on Greenbriar loop. These

results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

10.00

1.00 —

>

0.10 —

0.01 Location

Figure 20. Measured E-field levels scaled to 1 MW EIRP in the Martin Acres

neighborhood. These results are for a transmitter on Eldorado Mountain for a frequency

of 533 MHz, a transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m

(9.68 ft).

57
1.000

0.100

>

0.010

0.001

Figure 21. Measured E-field levels scaled to 1 MW EERP at the DOC Laboratories. These

results are for a transmitter on Eldorado Mountain for a frequency of 772 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

1.000

0.100 —

0.010 —

0.001

'

I

' I'

I

' Location

Figure 22. Measured E-field levels scaled to 1 MW EIRP at the Table Mountain NRQZ.

These results are for a transmitter on Eldorado Mountain for a frequency of 772 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

58
1.000

0.100 —

>

DOC to Hwy. 36 on 28th Street

0.010 —

0.001 Location Figure 23. Measured E-field levels scaled to 1 MW EIRP from the DOC Laboratories

down 28* Street to the Table Mountain NRQZ. These results are for a transmitter on

Eldorado Mountain for a frequency of 772 MHz, a transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

10.000 -rr

0.001 T 1 ! ] ! Location

Figure 24. Measured E-field levels scaled to 1 MW EIRP from Table Mountain NRQZ to Highway 72 via Highway 36, Broadway, and Highway 93. These results are for a

transmitter on Eldorado Mountain for a frequency of 772 MHz, a transmitter height of

3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

59
>

100.000 -^

10.000 —

1.000 —

0.100 -=

0.010 -=

0.001

Figure 25. Measured E-field levels scaled to 1 MW EIRP on the McCaslin loop. These

results are for a transmitter on Eldorado Mountain for a frequency of 772 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

10.000

Broadway to NCAR

1.000 —

0.100 —

0.010 —

0.001

Of<u

z NCAR to Broadway

r

Location Figure 26. Measured E-field levels scaled to 1 MW EIRP at the NCAR facility at the top

of Table Mesa. These results are for a transmitter on Eldorado Mountain for a frequency

of 772 MHz, a transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m

(9.68 ft).

60
10.000 -=r

0.001 Location

Figure 27. Measured E-field levels scaled to 1 MW EIRP in Eldorado Canyon. These

results are for a transmitter on Eldorado Mountain for a frequency of 772 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

1.000

0.100 —

>

0.010 —

0.001 Location Figure 28. Measured E-field levels scaled to 1 MW EIRP on County Road 67. These

results are for a transmitter on Eldorado Mountain for a frequency of 772 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

61
10.00

1.00 —

>

0.10 —

0.01

Fairview High School

Southern Hills Jr. High

M II M II

I

I

I

I PT I 'I'I'I'I'I'I'I'I'I'I'I'I

Location Figure 29. Measured E-field levels scaled to 1 MW EIRP on Greenbriar loop. These

results are for a transmitter on Eldorado Mountain for a frequency of 772 MHz, a

transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68 ft).

10.000 -zr

LocatioD

Figure 30. Measured E-field levels scaled to 1 MW EIRP in the Martin Acres

neighborhood. These results are for a transmitter on Eldorado Mountain for a frequency

of 772 MHz, a transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m

(9.68 ft).

62
0.01000

0.00100

>

0.00010 —

0.00001

Location Figure 31. Measured E-field levels scaled to 1 MW EIRP at the DOC Laboratories. These

results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

0.100

0.001 Location Figure 32. Measured E-field levels scaled to 1 MW EIRP at the Table Mountain NRQZ.

These results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

63
0.100

0.001 Location Figure 33. Measured E-field levels scaled to 1 MW EIRP from the DOC Laboratories

down 28'*^ Street to the Table Mountain NRQZ. These results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, a transmitter height of 8.2 m (26.9 ft), and

a receiver height of 2.95 m (9.68 ft).

0.100

0.010 —

0.001 Location Figure 34. Measured E-field levels scaled to 1 MW EIRP from the Table Mountain

NRQZ to Highway 72 via Highway 36, Broadway, and Highway 93. These results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, a transmitter height of

8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

64
>

1.0000 -^

0.1000 —

0.0100 —

0.0010 —

0.0001 Location Figure 35. Measured E-field levels scaled to 1 MW EIRP on the Boulder/Golden loop.

These results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

1.000

0.100 —

>

0.010 —

0.001 T I I

'

I Location Figure 36. Measured E-field levels scaled to 1 MW EIRP on the McCaslin loop. These

results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

65
0.010

>

Broadway to NCAR

TopofNCAR

NCAR to Broadway

0.001 T

Location Figure 37. Measured E-field levels scaled to 1 MW EIRP at the NCAR facility at the top

of Table Mesa, These results are for a transmitter on Squaw Mountain for a frequency of

533 MHz, a transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

0.100

0.001 Location Figure 38. Measured E-field levels scaled to 1 MW EIRP on Greenbriar loop. These

results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

66
0.01000

0.00100

>

0.00010 —

0.00001

Location Figure 39. Measured E-field levels scaled to 1 MW EIRP at the DOC Laboratories. These

results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

0.1000

0.0100

>

0.0010

0.0001 Location Figure 40. Measured E-field levels scaled to 1 MW EIRP at the Table Mountain NRQZ.

These results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

67
0.1000

0.0100

>

DOC to Hwy. 36 on 28th Street

0.0010

Hwy. 36 10 Table Mm.

0.0001 T

Location Figure 41. Measured E-field levels scaled to 1 MW EIRP from the DOC Laboratories

down 28* Street to the Table Mountain NRQZ. These results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, a transmitter height of 8.2 m (26.9 ft), and

a receiver height of 2.95 m (9.68 ft).

0.1000

0.0100

>

0.0010

0.0001 Location Figure 42. Measured E-field levels scaled to 1 MW EIRP from the Table Mountain

NRQZ to Highway 72 via Highway 36, Broadway, and Highway 93. These results are

for a transmitter on Squaw Mountain for a frequency of 772 MHz, a transmitter height of

8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

68
1.0000 -^

0.0001 Location Figure 43. Measured E-field levels scaled to 1 MW EIRP on the Boulder/Golden loop.

These results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

1.0000 -zi

0.0001 Location Figure 44, Measured E-field levels scaled to 1 MW EIRP on the McCaslin loop. These

results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

69
>

U. lUUU _

Broadway to NCAR

Of<

o

z NCAR to Broadway

O

0.0100 —

> AiII lA ,

0.0010 — w%

'

1

1

1 ' LocatioD Figure 45. Measured E-field levels scaled to 1 MW EIRP at the NCAR facility at the top

of Table Mesa. These results are for a transmitter on Squaw Mountain for a frequency of

772 MHz, a transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

0.0100

0.0001 Location Figure 46. Measured E-field levels scaled to I MW EIRP on the Greenbriar loop. These

results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, a

transmitter height of 8.2 m (26.9 ft), and a receiver height of 2.95 m (9.68 ft).

70
10.000

1.000

>

0.100

0.010 Location Figure 47. Measured E-field scaled to 1 MW EIRP at the intersection of Highway 93 and

Highway 72. These results are for a transmitter on Eldorado Mountain for a frequency of

533 MHz, a transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68

ft).

10.000

1.000

>

0.100

0.010 Location Figure 48. Measured E-field scaled to 1 MW EIRP at the intersection of Highway 93 and

Highway 72. These results are for a transmitter on Eldorado Mountain for a frequency of

772 MHz, a transmitter height of 3.66 m (12.0 ft), and a receiver height of 2.95 m (9.68

ft).

71
Eldorado Mt. ITS

Proposed site (533 MHz. i9-Mar-01 i3:44:5S CS065Marig01B.ques 199T Census1 Mw EIRPJHP)

Field In-consityCaBuv/m) CD Greater than 10 v/ra Area: O. sq km

Population: 0. HouGeriolds: O. 1 to lO V/m

Area; 30

Population: Houaeholda:

sq Km

O.

o.

.1 to 1 V/m

Area: 3aoQ sq km

Population: 1838000.

HouBeholds: 6-ATOOO.

.01 to .1 V/m

Area: 3BaO. sq km

Population: 364000.

Households: 1O30O0.

.001 to .01 V/m

Area: 15S0. eq km

Population: 133000.

Houaenolda: 41O0O.

.OOOl to .001 V/m

Area: 2740. sq km

Population: 4BOOO.

Households: 14000.

.00001 to .0001 v/m

Area: 3690. sq km

Population: zeooo.

Households: 7000. less cnan .ooooi vm

Area: 1990. sq km

PoDulation: 80OO. Households: 2000.

Figure 49. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on

Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter height of

3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

72
Eldorado Mt. ITS

Proposed sits (533 MHz, 1 Mw EIRP.VP) iQ-Mar-Ol 13:43^.4 CSOeSMarigOlA.ques 199T Census

Flaia iritonslty(aBuv/m)

I I Greater tnan lo v/m

Araa: O. sq km

Population: O. Houssnoids: o. 1 to 10 v/m

Area: 30. sq Km

PoDulation: O. Householda: O.

"^35 .i to 1 V/m

Area: 3S0O sq Km

PoDulatlon: 1838000.

Hou&eholds: ©4."70O0.

.01 to .1 v/m

Area: 3Bao. sq km

Population: 364000.

Mousenolds: 103000.

.001 to .01 V/m

Ares: 1590. sq I<ni Population: 13-4000. Housenolds: 4100O.

.0001 to .001 V/m

Area: 2770. sq km

Population: 4BOOO.

Households: 14000.

-' -OOOOl CO .OOOl v/m

Area: 3760. sq km

Population: 2SD0O.

Households: 7QO0.

less tnan .ooooa v/ra Area: 1890. sq km Population: TOOO. Housanolds: 2000.

Figure 50. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a vertically polarized antenna. These results are for a transmitter on

Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter height of

3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

73
Eldorado Mt. ITS

Proposed sits (772 MHz, 1 Mw EIRP.HP) 19-Mar-Oi 13:56:03 CS065Marl901D.ques 1997 Census

Flaia Intenslcy(dBuv/m) dl Greater than lO v/m

Area: 0. sq km

PoDulotion: 0. Housenoias: o. ± to 10 V/m

Area: 30. sq Km

Population: O. Houaeholda: O. " i to 1 V/ra Area: 3780. sq km

Population: 1328000.

Households: 64.3000. ^ X>± to .1 V/m

Area: 3S0O. sq km

Population: 34.8Q0O. Householda: 98000.

X501 to .01 V/m

Area: 1390. eq km Population: 145000.

Households: 44000.

"'' JDOOl to .OOl V/m

Area: 2470. sq km

Population: S50Q0.

Households: leOOO.

.00001 to .0001 v/m

Area: 2920. sq km

Population: 2BOOO. Housaholds: aOOO.

less than .00001 v/m

Area: 3430. sq km

Population: 140OO. Housahoias: 4000.

Figure 51. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on

Eldorado Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter height of

3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

74
Eldorado Mt. ITS

Proposed site (772 MHz, 19-Mar-Oi 13:46:48 CS065MarigoiC.ques 1997 Census

Field Intenslty(dBuv/m)

I I Greater than iO V/m Araa: 0. sq km

Population: O. Househoias; O. ON 1 to 10 v/m

Area: 30. sq Km

PoDulatlon: O. HDusenolOs: 0.

.1 to 1 V/m

Area: 37ao. sq km

PoDUlatlon: 1326000. Hdu&b holds: 64-3000. ^ .01 to .1 V/m

Area: 3BOO- sq km

Population: 348000,

Households: 98000.

.001 to .01 V/m

Ar^a: 1-4.00. sq km

Population: 145000.

Households: 44000.

.0001 to .001 V/m

Area: 2490. sq km

Population: S500O.

Households: ISOOO.

.00001 to .OOOl v/m

Area: 2970. sq km

Population: 2S0OO.

Households: aOOO.

less tnan .OQOOi v/m

Area: 33e0. sq km

Population: 14000. Households: -4000.

1 Mw EIRP.VP)

Figure 52. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a vertically polarized antenna. These results are for a transmitter on

Eldorado Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter height of

3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

75
1.000 —

Doc 10 Hwy. 36 on 28lh Street

o

a

a:

Table Mtn.

— -.____

> 0.100 —

0.010 — \r/

1

1 Location Figure 53. Modeled (or predicted) E-field levels on the 28* Street Route. These results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a

transmitter height of 3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

a o

Q

1.000 — r

-^"^^

> 0.100 —

0.010 — jf

' 1

1 Location Figure 54. Modeled (or predicted) E-field levels on the Broadway Route. These results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a

transmitter height of 3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

76
10.000 -rr

0.001 Location

Figure 55. Modeled (or predicted) E-field levels on the McCaslin Loop. These results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a

transmitter height of 3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

10.00

1.00 —

>

0.10 —

0.01 Location Figure 56. Modeled (or predicted) E-field levels at the Table Mountain NRQZ. These

results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, EIRP=1

MW, a transmitter height of 3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

77
10.00

1.00 —

>

0.10 —

0.01 Location

Figure 57. Modeled (or predicted) E-field levels at the DOC Laboratories. These results are for a transmitter on Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a

transmitter height of 3.66 m (12 ft), and a receiver height of 2.95 m (9.68 ft).

78
Squaw Peak ITS

Proposed site (533 MHz, 224 kw, VP) 5-Mar-Ol 13:06:22 CSOeSMarOSOlD.ques 1997 Census

Flaia IntenslCyCaBuv/m) Greater trian lO V/CT Arsa: 0. sq km

PoDulQtion: 0. Housenoias: 0. 1 to lO V/m

Area: 10. sq Km PoDulation: 0. HDusenoiaa: O.

--- J. to 1 V/m

Area: 1.3B0. sq kra PoDulatlon: 1205000.

Households: 439000.

JOl to .1 V/m

Area: 49S0. sq km

Population: S590QO.

Households: 18900O.

1)01 to .01 V/m

Area: 2580. sq km

Population: 32200O.

HouBsholds: lOlOOO. '^ j:001 to .001 V/m

Area: 2980. sq km

Population: ISTOOO.

Households: 44000.

- " JDOOOl to .OOOl v/ra Area: 3930. ea km

Population: DOOOO. HOUS9 holds: 3QQ00.

less than .00001 v/m

Area: 20O0. sq km

Pooulation: 5O0O. Housanoias: lOOO.

Figure 58. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter height of 8.20

m (26.91 ft), and a receiver height of 2.95 m (9.68 ft).

79
Squaw Peak ITS

Proposed site t533 MHz. 224 kw. VP) 5-Mar-Ol 13:04:40 CSOeSMarOSOlCques 1997 Census

Plaid :ntonElty<aBuv/m) CH Greater than ID v/m

Area: 0. sq km

PopulQ-tion: O. Househoias: O. N 1 to lO v/m

Area: 10. sq Km

PoDulation: 0. Housenoiaa o.

J. to 1 V/m

Area; 13B0. sq Kra PoDulatlon: 1205000.

Households: 438000. ^ jOI to .1 V/m

Area: 49B0. sq Km

Population: 659O0O.

Households: 19B00O.

X)01 to .01 V/m

Are©: 2500. SQ Km

Population: 323O0O.

Households: ±02000. ^ JDOOl to .001 V/m

Area: 30O0. bo l^m Population: a3BOOO.

Households: 43000.

• J30OO1 CO .OOOl v/m

Area: 3960. so km

Population: BOOOO.

HousQholds: 3QO00.

less than .ooooi v/ra Area: 1940. sq kra Populetion: 5O0O. Housanoias: iQOO.

Figure 59. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a vertically polarized antenna. These results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter height of 8.20

m (26.91 ft), and a receiver height of 2.95 m (9.68 ft).

80
Squaw Peak ITS

Proposed site (772 MHz. 224 kw. le-Mai—Ol 16:37:20 CSOeSMarieOlF.ques 1997 Census

RlQia Intensity(a Buv/m)

CZI Greater than lo V/m

Area: O. sq km

Population: O. Housenolds: O.

iN 1 to lO v/m

Area: 10. sq Km

PoDulation: O. Households: O.

J. to 1 V/m

Area: 1350. sq Km

Population: 1202000.

Households: 43B000. ni to .1 V/m

Area: 4B10. sq km

Population: 630000.

Households: 19800O.

£101 to .01 V/m

Area: 21©0. 5q Km

Population: 2B10OO.

Households: S9000.

'" ' JDOOl to .001 V/m

Area: 2460. sq km

Population: 15BDOO.

Households: 46000.

J300O1 to -OOOi v/m

Area; 3770. eq km

PODulatiOn: 1240OO.

Housaholds: 43000.

less than .OOOOi v/ra Area: 3270. sq km

Population: 23O0O.

HousQhoias: TOOD.

HP)

Figure 60. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter height of 8.20

m (26.91 ft), and a receiver height of 2.95 m (9.68 ft).

81
Squaw Peak ITS

Proposed site (772 MHz. 224 kw. VP) 16-Mar-Ol 16:35:29 CS065Msr±601E.que3 1997 Census

Flald ]ntenslcy(dBuv/m)

CD Greater tnan lO v/m

Area: 0. sq km

PoDuletion: O. House noias: o.

iN 1 to lo v/m

Araa: 2.0. sq Km PoDulation: 0. Households: O.

J. to 1 V/m

Area: 1350. sq Km

PoDulatlon: 12O20OO. Hou&eholds: 438000. ^ JOl to .1 V/m

Area: 4-SlO. sq km

Population: S30000.

Households: 16900O. ^01 to .01 V/m

Area: H160. eq km Population: 2B10O0.

Households: S9000.

•~ £1001 to .001 V/m

Area: 2480. sq Km

Population: 15DOOO.

Households: 49000.

X30001 CO -OOOl v/m

Area: 3790. eq km

Population: 124000.

Households: 44000.

less Chan .OOOOl v/m

Area: 3210. sq km

Population: 22O0O. House noios: 7000.

Figure 61. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a vertically polarized antenna. These results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter height of 8.20

m (26.91 ft), and a receiver height of 2.95 m (9.68 ft).

82
0.010

>

0.001 Location Figure 62. Modeled (or predicted) E-field levels at the Table Mountain NRQZ. These

results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, EIRP=1

MW, a transmitter height of 8.20 m (26.91 ft), and a receiver height of 2.95 m (9.68 ft).

1.00000 -=,

0.10000 —

0.01000 -= B>

0.00100 —

0.00010 —

0.00001 Location Figure 63. Modeled (or predicted) E-field levels on the McCaslin Loop. These results are

for a transmitter on Squaw Mountain for a frequency of 533 MHz, EIRP=1 MW, a

transmitter height of 8.20 m (26.91 ft), and a receiver height of 2.95 m (9.68 ft).

83
10.00000

0.00001 Location

Figure 64. Modeled (or predicted) E-field levels on the Golden/Boulder Route. These

results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, EIRP=1

MW, a transmitter height of 8.20 m (26.91 ft), and a receiver height of 2.95 m (9.68 ft).

84
Eldorado Mountain ITS

Proposed site (533 MHz. 1 Mw EIRP) i9-Mar-01 iB:3S:15 CS065Marl901U.ques 1997 Census

Flala IntonsltyCdBuv/m) CD Greater tnan lO V/m

Arsa: O. sq km

Populetion; O. Houeenoias: o. ON 1 -to lO V/m

Area: 50. sq Km

Population: 1000. House hQLCJ3: O.

.1 to 1 V/m

Area: 4030 sq Km

Population: 1855000.

Households: eS-AOOO. ^* .01 to .1 V/m

Area: -4160. sq km

Population: 35S0OO.

Householda: lOOOOO.

.OOi to .01 V/m

Ares: 1T30. sq kra Population: 12B0OO.

Households: 36000. "^ .0001 to .001 V/m

Arsa: 2170. sq km

Population: 3e00Q.

Households: 11000.

'— .OOOOI to .0001 v/m

Area: 3440. sq km

Population: 30000.

Households: 9000. less cnan .ooooa v/ra Area: 2220. sq Km

Population: SOOO. Housenoios: 2000.

Figure 65. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on

Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter height of

116 m (379 ft), and a receiver height of 2 m (6.56 ft).

85
Eldorado Mountain ITS

Proposed site (772 MHz. 1 Mw EIRP)

19-Mar-Ql 16:40:53 CS06SMan901V.ques 1997 Census

Floia iotonslcy(aBuv/m) Greater -tnan iO wTM

Area: 0. sq km

PoDuletion: 0. Houeehoias: o. 1 to 10 v/m

Area: 50. sq Km

PoDulation: 1000. Housenoiaa: O.

.1 to 1 v/m

Area: -4010. sq km

PoDulatlon: 184.5000.

Househalcls: 6510OO.

J3± to .1 V/m

Area: 403O sq km

Population: 34300O.

Mousenolds; 850O0.

.001 to .01 V/m

Area: 1430. sq km Population: 134-000. Houaeholds: 41000.

,0001 to .OOl V/m

Area: 1870, sq km

Population: 4BOOO.

Households: 14000,

.OOOOi to .OOOi v/m

Area: 2660, sq km

PODulatiOn: 300OO.

Housaholds; aooo.

less cnan .ooool v/m

Area: 3770. sq km

Population: 17000. Housanolds: SOOO.

Figure 66. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on

Eldorado Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter height of

116 m (379 ft), and a receiver height of 2 m (6.56 ft).

86
10.00

1.00 —

>

0.10

0.01

:

- f=54 MHz

_

^

-

-

^FCC Quiet-Zone Limit

-

1

1 Location

Figure 67. Modeled (or predicted) E-field levels at the Table Mountain NRQZ. These

results are for a transmitter on Eldorado Mountain, EIRP=1 MW, a transmitter height of

1 16 m (397 ft), and a receiver height of 2 m (6.56 ft).

10.00

1.00

>

0.10

0.01

f=54 MHz

f=533 MHz

f=772 MHz

Location

Figure 68. Modeled (or predicted) E-field levels at the DOC Laboratories. These results are for a transmitter on Eldorado Mountain, EIRP=1 MW, a transmitter height of 116 m

(397 ft), and a receiver height of 2 m (6.56 ft).

87
Squaw Peak ITS

Proposed site (533 MHz. 1 Mw EIRP) 20-Mar-Ol 08:43:47 CSOeSMarSOOlB.ques

iggy census

Floia Inronslty(aBuv/m)

I I Greater tnan lO V/m Arsa: O. sq km

Population: O. Households: O. ON 1 -to 10 v/m

Area: lO. sq km Population: 0. HousenolcJa; O.

.1 to 1 V/m

Area: ISOO. sq Km

Population: 1223000.

HoLJ9eholcl3; *IA5000. ^ .01 to ,1 v/m

Area: 5-4SO. sq km

Population: SS9000.

Mouaeholds: 207O00.

.001 to .01 V/m

Area: 2360. 5p km

Population: 2T3000.

Households: aeooo.

.0001 to .001 V/m

Area: 2680. sq Km

Population: izyooo.

Households: 40000.

.OOOOi to .OOOi v/m

Area: 4370. sq km

Population: 1O300O.

Households: 36000.

less tnan .OOOOI v/m

Area: 1230. sq Km

PoOLJlatiDn: 300O. Housanolds: lOOO.

Figure 69. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter height of

60.96 m (200 ft), and a receiver height of 2 m (6.56 ft).

88
Squaw Peak ITS

Proposed site (772 MHz, 1 Mw EIRP)

19-Mar-Ol 16:23:57 CS065Mari9010.ques 1997 Census

Flaia Intonslt.y(aBuv/m)

I I Greater tnan lo V/m

Area: O. sq Km

PoDulation: 0. WOUSG holds: o. 1 to lO V/m

Area: lO. sq Km

Population: 0. Householda: o. "- .1 to 1 V/m

Area: 1-4BO. sq Km

Population: 1221000.

Households: 4-4.5000.

.01 to .1 V/m

Area: 5310. sq km

Population: 66S00O.

Households: 19S00O.

.001 to .01 V/m

Area: 1S90. &Q km

Population: 2330QO.

Households: 74000.

.0001 to .001 V/m

Area: 2400. sq km

Population: 141000.

Households: 420O0.

.00001 to .OOOi v/m

Area: 4040. sg km

Population: 12S0OO.

Households: 450O0.

less tnan .00001 v/m

Area: 2690. sa Km

Population: 2S00O.

Housanoias: 9000.

Figure 70. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter height of

60.96 m (200 ft), and a receiver height of 2 m (6.56 ft).

89
1.0000

0.1000

> 0.0100 —

0.0010 —

0.0001

f=54MHz

f=533 MHz

f=772 MHz

FCC Quiet Zone Limit {533 MHz and 772 MHz)

FCC Quiet Zone Limit (54 MHz)

Location

Figure 71. Modeled (or predicted) E-field levels at the Table Mountain NRQZ. These

results are for a transmitter on Squaw Mountain, EIRP=1 MW, a transmitter height of

60.96 m (200 ft), and a receiver height of 2 m (6.56 ft).

t

!

90
Eldorado Mountain ITS

Proposed site (533 MHz. 1 Mw EIRP)

19-Mar-Ol 16:32:16 CS065Marl901R.ques 199T Census

Flaia Intonslty(aBuV/m)

I I Greater than ±0 V/m

Area: O. sq Km

Population: 0. Households: o. ON 1 -to lO V/m

Area: 60. sq Km

Population: 1000. HouaehQlos; O,

.1 to 1 V/m

Area: 42TO. sq km

PoDulatlon: 1935000.

Households: eTSOOO.

.01 to .1 V/m

Area: -4310. sq km

Population: 308000.

Households: 64000.

.001 to .01 V/m

Aree: 1320. sp km

Population: 9T00O.

Housenolds: 290O0.

.0001 to .001 V/m

Area: 2010. sq km

Population: 3B00O.

Households: 11000.

^5© .00001 to .OOOi v/m

Area: 3090. sq km

Population: 2S00O.

Houssholds; 8000.

less tnan .OOOOl v/m

Area: 2760. sq km

Population: IZOOO. Housanoios: 3000.

Figure 72. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on

Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter height of

1 16 m (379 ft), and a receiver height of 9.14 m (30 ft).

91
Eldorado Mountain ITS

Proposed site CT72 MHz. 1 Mw EIRP) i9-Mar-01 16:34:30 CS065Mari901S.ques 1997 Census

Flald IntonsltyCaBuV/m) Greater than lO V/m

Area: O. sq km

Population: 0. Hou&eriolds: O.

i. %o ±0 V/m

Area: 30. sq Km

Population: 1000. Housenoiaa: o. " .1 to 1 V/m

Area: 4230. sq km

Population: 1931000.

Households: STSOOO. i" .01 to .1 V/m

Area: 4210. aq km Population: 29200O.

Households; TSOOO.

.001 to .01 V/m

Area: 1050. sq km

Population; lOlOOO. Mouaehoiaa: 31000.

.0001 to .OOi V/m

Area: 1S80. sq Km Population: 44000. Households: 13000.

"=-'1 .OOOOl to .OOOi v/m

Area: 2340. sq km

Population: 2B00O.

Households: SOOO.

less cnan .ooooi v/ra Area: 4240. sq km

PoDulation; 200O0.

Households: 6000.

Figure 73. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on

Eldorado Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter height of

116 m (379 ft), and a receiver height of 9.14 m (30 ft).

I

I

I

I

92
Squaw Peak ITS

Proposed site (533 MHz. 1 Mw EIRP) 20-Mar-Ol 08:47:14 CS065Mar2001A.ques 1997 Census

Floia Inronslcy(aBuv/m)

CZl Greater tnan lO V/ra 'krea: O. sq Km

Population: O. Hou&eholds: o. ON 1 tJa lO V/m

Area: lO. sq Kra PoDulation: O. House holda; o. e:^ .1 to 1 V/m

Area: IBOO. sq km

PoDulatlon: 1276000.

Households; 4QSOOO.

.01 to .1 V/m

Area: 5QTO. sq km

Population: S680QO.

Housenolds: 200000.

.001 to .01 V/m

Ares: 1950. sq km

Population: 22Q0O0.

Housenolds: esooo.

~*^ .0001 to .001 V/m

Area: 2610. sq kra Population: 12S000.

Households: 37000.

'' .OQOOi to .OOOx v/m

Area: 4240. sq km

Population: 120000.

Households: 420O0.

less tnan .OOOOl v/m

Area: 1730. sq km

Population: llOOO. Households: 40OO.

Figure 74. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on Squaw Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter height of

60.96 m (200 ft), and a receiver height of 9.14 m (30 ft).

93
Squaw Peak ITS

Proposed site (772 MHz, 1 Mw EIRP) i9-Mar-01 lSd.6:S5 CS065Mari901L.ques

1997 Census

Floia inr»nslty(aBuv/m) Greater than lo V/m

Area: O. sq Km

Population: 0. Hou&enolds: O. 1 to lO V/m

/\raa: 10. sq Km

Population: 0. HouaehQlcia: o. "^'

.1 to 1 V/m

Area: laoo. sq kra PoDulatlon: 1274000.

Hou&ehaXds: 4.Q20O0.

.01 to .1 V/m

Area: seso. sq km

Population: S5500O.

Households: 18S00O.

.001 to .Ol V/m

Aree: 14.90. sq Km

Population: 172000.

Houaenolds: 55000. ~" .OOOl to .001 V/m

Area: 2160. sq km Population: ISIOOO.

Households: 460O0.

.OOOOl to .OOOl v/m

Area: 3710. sq l<ra Population: 12-4000. Households: 42000.

less tnan .OOOOl v/rn Area: 330O. sq km

PoDulation: 41000. Housanolds: ISOQO.

Figure 75. Contour plot of the modeled (or predicted) E-field levels around the DenverBoulder area for a horizontally polarized antenna. These results are for a transmitter on Squaw Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter height of

60.96 m (200 ft), and a receiver height of 9.14 m (30 ft).

i

[

I

I

94
Eldorado Mountain ITS

Proposed site (533 MHz. 1 Mw EIRP)

i9-Mar-01 15:07:49 CS065Mari901F.ques 1997 Census

Field IntenaltytdBuV/ml

I I Q-aacar tnan 4-1. Area. 11B60. sg km

POOLaatiOn: 2377000.

McKJsahoLds: 803000. u&ss than -41 Area: 69S0. aa km

Pooulatton: 40000.

Housanoias: 12000.

Figure 76. Area coverage plot of the 41 dB[iV/m FCC recommendation around the

Denver-Boulder area for a horizontally polarized antenna. These results are for a

transmitter on Eldorado Mountain for a frequency of 533 MHz, EIRP=1 MW, a

transmitter height of 116 m (379 ft), and a receiver height of 9.14 m (30 ft).

95
Eldorado Mountain ITS

Proposed site (772 MHz. 1 Mw EIRP) 19-Mar-Ol 15:05:38 CS065Mari901E.ques 199T Census

-30' Field IntensltyldBuV/m)

I I GraaMT than Ai. Area: 11140. sq km

PoqLaatLjQn: 23eaooo.

Households; 600000.

I. ps<;.s than **1 Area: 6S80. 30 km

PoDulatLon: 50O00.

Houssnoias: 1-4000.

Figure 77. Area coverage plot of the 41 dBjiV/m FCC recommendation around the

Denver-Boulder area for a horizontally polarized antenna. These results are for a

transmitter on Eldorado Mountain for a frequency of 772 MHz, EIRP=1 MW, a

transmitter height of 1 16 m (379 ft), and a receiver height of 9.14 m (30 ft).

96
Squaw Peak ITS

Proposed site (533 MHz. 1 Mw EIRP)

i9-Mar-01 16:04:13 CS065Mari901H.ques 1997 Census

Field Inten3lty(dBuV/m)

I I Q-aatar tnan .QOOl v

Area: 1170O. 3C1 km

PQciLaation: aaa^ooo.

Households; 768000,

Ljess than .oooi v/m

/V-ea: 6120. aa km

Pooulatian: 134000.

HQusanoias: 46000.

Figure 78. Area coverage plot of the 41 dB|a,V/m FCC recommendation around the

Denver-Boulder area for a horizontally polarized antenna. These results are for a

transmitter on Squaw Mountain for a frequency of 533 MHz, EIRP=1 MW, a transmitter

height of 60.96 m (200 ft), and a receiver height of 9.14 m (30 ft).

97
Squaw Peak ITS

Proposed site (772 MHz. 1 Mw EIRP) i9-Mar-01 16:05:54 CS065Mari901 1 .ques 1997 Census

-30' Field Inter>3lty(dBuV/in)

I I Q-eatar than .QOOl V

Area; 1069a aq km

PoqulatiDn: 22SQOO0.

HousahoLds: 757QO0.

""' Lj&ss rnan .oooi v/m

Area: 7130. sg km

PoqulBtlan: 16aO(X5. Housanolds: SSQOO.

Figure 79. Area coverage plot of the 41 dBj^V/m FCC recommendation around the

Denver-Boulder area for a horizontally polarized antenna. These results are for a

transmitter on Squaw Mountain for a frequency of 772 MHz, EIRP=1 MW, a transmitter

height of 60.96 m (200 ft), and a receiver height of 9.14 m (30 ft).

98
Figure 80. Arrangement of broadband, log periodic antenna (1) used to replicate field

intensities predicted from DTV transmitters on Eldorado Mountain (arrow). A GPS

receiver antenna (2), located on the NIST/TTS Radio Building at the DOC Laboratories,

is the target of the incident field in this test.

99
100
APPENDIX A: MEASURED E-FIELD STRENGTHS OF THE

1998 AND 2001 SPECTRUM SURVEY

In this appendix the measured data for the spectrum survey performed at both the Table

Mountain NRQZ and the DOC Laboratories are presented. The data in each graph were

acquired with a measurement system as described in Section 2. Figures A.l through A.34

are the measured E-field strengths for a vertically polarized receiving antenna. These

data are for the 1998 spectrum survey. Figures A.l through A. 17 are the measured E-field

strengths at the Table Mountain NRQZ for the frequency range of 30 MHz to 960 MHz.

Figures A. 18 through A.34 are the measured E-field strengths on the groundscreen at the

DOC Laboratories for the frequency range of 30 MHz to 960 MHz.

Figures A.35 through A.43 are the measured E-field strengths for a horizontally polarized

receiving antenna. These data are for the 2001 spectrum survey. Figures A.35 through

A.37 are the measured E-field strengths at the Table Mountain NRQZ, at the NIST

groundscreen, and at the end of Wing 4 of Building 1 at the DOC Laboratories for the

frequency range of 50 MHz to 90 MHz. Figures A.38 through A.40 are the measured Efield strengths at the Table Mountain NRQZ, at the NIST groundscreen, and at the end of

Wing 4 on Building 1 at the DOC Laboratories for the frequency range of 170 MHz to 220 MHz. Figures A.41 through A.43 are the measured E-field strengths at the Table

Mountain NRQZ, at the NIST groundscreen, and at the end of Wing 4 of Building 1 at the DOC Laboratories for the frequency range of 500 MHz to 800 MHz.

The upper curve shows the highest level in each bin from any of the sweeps, the lower

curve shows the lowest level in each bin from any of the sweeps, and the middle curve shows the average level in each bin for the entire set of sweeps. The data graphs may be

interpreted as follows: the maximum curve on each graph shows the absolute envelope of

received signal levels for the period of the spectrum survey. The minimum curve on each

graph shows the absolute minimum level observed on each frequency for the period of

the survey, and the middle curve shows the average level (in decibels) at each frequency

for the period of the survey. Generally, the variation between the sets of curves in each

2001 data graph is less than for the 1998 survey results because the measurements were made over shorter intervals (a few hours at each location).

In cases in which only noise was measured, the three curves are spaced about 10 dB

apart, and the average (middle) curve is at the measurement system's inherent noise level.

If signals were sporadically present on a frequency, then the average curve may be close

to the measurement system's inherent noise level, but the maximum and minimum curves

will be somewhat elevated. The closer the average curve is to the maximum curve, the

larger the percentage of time that the signal was present. If all three curves are elevated

above the measurement system's inherent noise threshold, then the signal was present in

all measurement scans. The closer the curves are together, the more constant the

measured signal level. The more the curves are spread apart, the more variation occurred

in the measured signal level. The average curve's proximity to the maximum or minimum

curves indicates whether the signal was present in a large percentage of scans or a low

percentage of scans, respectively. The absolute percentages of time that signals were

present are not available in these data graphs.

101
I

I

£ 60 >

m

S. 50

B 40

30

c 20

10

-10

CFB 47 quiet zone field str ^gthllimit ;

^4yliiv ijLLk- ,

1 'LiiM^ W^^

Li , • >. luLki'l L

,111,1 iiUL.Jltlfr'^^ : ^ wA«Mu^\Ju^*mMi,w>4«m.»i^,^J'*'''**—

k4M lA«!«iN»W^^k.H,JiM^MiMuL.

30 35 40

Frequency (MHz)

45 50

Figure A.l. Table Mountain NRQZ, 30-50 MHz, 10 kHz IF bandwidth, 6,300 sweeps,

vertical polarization.

102
70

Frequency (MHz)

Figure A.2. Table Mountain NRQZ, 50-90 MHz, 10 kHz IF bandwidth, 1,890 sweeps,

vertical polarization.

100

Frequency (MHz)

Figure A.3. Table Mountain NRQZ, 90-110 MHz, 10 kHz IF bandwidth, 1,890 sweeps,

vertical polarization.

103
116 120

Frequency (MHz)

Figure A.4. Table Mountain NRQZ, 104-134 MHz, 12,400 sweeps, vertical polarization.

140 150

Frequency (MHz)

160 170

Figure A.5. Table Mountain NRQZ, 134-170 MHz, 10 kHz IF bandwidth, 12,400 sweeps,

vertical polarization.

104
190 200

Frequency (MHz)

220

Figure A.6. Table Mountain NRQZ, 170-220 MHz, 100 kHz IF bandwidth, 31,500

sweeps, vertical polarization.

70

60

50

g" 40 5

m

S- 30

B 20

CO

"• 10

S

-10

-20

-30

cfr;47 quiet zone field istrength I mil is +80 dBuV/m

^ iwiifmUU*i > yilW iy(N^lJ^^)^<^^^^i»iJ^^<>^lJ^^ mi*mhimJiUww L^ " —' " ' r'

iimt,0i*lt ^iv¥iW i^Njp riNj^^vJJiutJMKpif^^

219 221 223

Frequency (MHz)

225

Figure A.7. Table Mountain NRQZ, 219-225 MHz, 3 kHz IF bandwidth, 7,380 sweeps,

vertical polarization.

105
90

80

70

e" 60 S 50

£ 40

30

c 20

10

-10

i CFR i47 qui it zone field strengtfi limit

: i 1 L 1 ;

1

lll^ liiLk Ui^kMiiJ iLaiWWIII ^|U| j|^ L i

jlI' b 1 <i I ihiiji 1. 1 1 i ,, 1 1

1

i ,i .1. ; .. I 1 ,:

: 1 : : 250 300

Frequency (MHz)

350 400

Figure A.8. Table Mountain NRQZ, 225-400 MHz, 30 kHz IF bandwidth, 5,800 sweeps,

vertical polarization.

CFR 47 quiet zc^e field strength 1 n ft

00

i M 1 ; ai^mI S M M

^ 1 «

c

; I ...l ..^. SiL** , .u M

«

toUu^ X L.^.Ll^ •g 20 o

c

-10

400 402 404

Frequency (MHz)

406

Figure A.9. Table Mountain NRQZ, 400-406 MHz, 10 kHz IF bandwidth, 36,600 sweeps,

vertical polarization.

106
406 410 414

Frequency (MHz)

418

Figure A. 10. Table Mountain NRQZ, 406-420 MHz, 10 kHz IF bandwidth, 36,400

sweeps, vertical polarization.

120

110

100

g 90 >

CDS 80

CFFi 47 quiet zone ield strength lir lit i i i 1 :::/

—M-^

:—^ : ^v^

^ I

; ; ; ^^ MM/

M--t-M-r/

—^

420 430 440 450

Frequency (MHz)

Figure A. 11. Table Mountain NRQZ, 420-450 MHz, 1 MHz IF bandwidth, 120 passes

through band (stepped), vertical polarization.

107
450 455 460

Frequency (MHz)

465 470

Figure A. 12. Table Mountain NRQZ, 450-470 MHz, 10 kHz IF bandwidth, 36,300

sweeps, vertical polarization.

470 480 490

Frequency (MHz)

500 510

Figure A. 13. Table Mountain NRQZ, 470-512 MHz, 10 kHz IF bandwidth, 18,000

sweeps, vertical polarization.

108
100

520 560 600 640 680

Frequency (MHz)

720 760 800

Figure A. 14. Table Mountain NRQZ, 512-812 MHz, 100 kHz IF bandwidth, 12,000

sweeps, vertical polarization.

90

80

70

60

50

40

CFR 47 quiet fcone ield strength limit;

|: ill iJi y

jiiiii ^1 , • iJ

M . 1 1 II i iMk ;

1 1

1 - 1

1

1 i 1 i li Hii 1 , i 1 1

20 1il iiiiiiiliJ Mil '-' \ Jj, 10 : : ; 1

mmHiim i^mI Ji

825 850

Frequency (MHz)

875 900

Figure A. 15. Table Mountain NRQZ, 806-906 MHz, 10 kHz IF bandwidth, 7,200 sweeps,

vertical polarization.

109
110

900 910 920 930

Frequency (MHz)

Figure A. 16. Table Mountain NRQZ, 900-930 MHz, 10 kHz IF bandwidth, 120 sweeps,

vertical polarization.

110

930 940 950 960

Frequency (MHz)

Figure A. 17. Table Mountain NRQZ, 930-960 MHz, 53,700 sweeps, vertical polarization.

110
40

Frequency (MHz)

Figure A. 18. NIST groundscreen, 30-50 MHz, 10 kHz IF bandwidth, 8,400 sweeps,

vertical polarization.

90

80

70

g 60 3

CQS 50

Z 40

t 30 c

o

"oS 20

10

-10

1 1 1

i|

1 . _ . 1 J 1 \[

1

' i*L 1^

l^Wn ^W^Wff ^\w^vwm

ii.i^,iLii.i ' ^« 1

iiJ^ .>

>^r«M -^

xJ[J ; ykdjj^ ^»*»'''; >U--4iLJjii

JlL»>,i...... i>r«-*.--i-*^iFfWr^ IPf WO'* lliiiniKi

i '"i" il"!

50 60 70

Frequency (MHz)

80 90

Figure A. 19. NIST groundscreen, 50-90 MHz, 10 kHz IF bandwidth, 3,060 sweeps,

vertical polarization.

HI
100

Frequency (MHz)

110

Figure A.20. NIST groundscreen, 90-110 MHz, 10 kHz IF bandwidth, 3,060 sweeps,

vertical polarization.

116 120

Frequency (MHz)

Figure A.21. NIST groundscreen, 104-134 MHz, 10 kHz IF bandwidth, 21,600 sweeps,

vertical polarization.

112
140 150

Frequency (MHz)

160 170

Figure A.22. NIST groundscreen, 134-170 MHz, 10 kHz IF bandwidth, 21,600 sweeps,

vertical polarization.

170 180 190 200 210 220

Frequency (MHz)

Figure A.23. NIST groundscreen, 170-220 MHz, 100 kHz IF bandwidth, 50,000 sweeps,

vertical polarization.

113
-20

-30

)»t(li(ff*f/i\>^ itf(IHifi}l,f^*i^ *W«

219 221 223 225

Frequency (MHz)

Figure A.24. NIST groundscreen, 219-225 MHz, 3 kHz IF bandwidth, 11,760 sweeps,

vertical polarization.

90

80

70

g" 60 >

CQS. 50

30

c 20

\

J i ii__ Ikii ,1 ,1 J 1,1 L .

1 ibiiLii Ml 1 1 i .L ,,ll, Ih, 1 1

J U illliilililliVUII ii

iMlUUL

250 300

Frequency (MHz)

350 400

Figure A.25. NIST groundscreen, 225-400 MHz, 30 kHz IF bandwidth, 9,600 sweeps,

vertical polarization.

114
400 402 404

Frequency (MHz)

406

Figure A.26. NIST groundscreen, 400-406 MHz, 58,800 sweeps, vertical polarization.

on 40

406 410 414

Frequency (MHz)

418

Figure A.27. NIST groundscreen, 406-420 MHz, 10 kHz IF bandwidth, 58,600 sweeps,

vertical polarization.

115
120

110

100

•g 90 m

2, 80 £

o>c

a

70 W

60

c 50

40

30

20

A 1

A^ A A aI L IN /uy \^ \\ /u^^ /^ Aa.1

\'

'

. r I

i \

i

X ^r^— i i

1 ^

420 430 440 450

Frequency (MHz)

Figure A.28. NIST groundscreen, 420-450 MHz, 1 MHz IF bandwidth, 193 stepped

passes, vertical polarization.

450 455 460

Frequency (MHz)

465 470

Figure A.29. NIST groundscreen, 450-470 MHz, 10 kHz IF bandwidth, 58,500 sweeps,

vertical polarization.

116
470 480 490

Frequency (MHz)

500 510

Figure A.30. NIST groundscreen, 470-512 MHz, 10 kHz IF bandwidth, 29,000 sweeps,

vertical polarization.

ICO

520 560 600 640 680

Frequency (MHz)

720 760 800

Figure A.31. NIST groundscreen, 512-812 MHz, 100 kHz IF bandwidth, 19,200 sweeps,

vertical polarization.

117
825 850

Frequency (MHz)

875 900

Figure A.32. NIST groundscreen, 806-906 MHz, 10 kHz IF bandwidth, 11,760 sweeps,

vertical polarization.

110

900 910 920 930

Frequency (MHz)

Figure A.33. NIST groundscreen, 900-930 MHz, 10 kHz IF bandwidth, 195 sweeps,

vertical polarization.

118
MU iMMw Jrtui w

tm04m0mfmmlmi>rmm0t

930 940 950 960

Frequency (MHz)

Figure A.34. NIST groundscreen, 930-960 MHz, 10 kHz IF bandwidth, 87,000 sweeps,

vertical polarization.

-10

Mea^urennient n^ise flfjor ra|sed ip dB

due jo external ^nenu^tlon 50 60 70

Frequency (MHz)

80 90

Figure A.35. Table Mountain NRQZ, 50-90 MHz, 10 kHz IF bandwidth, 2,300 sweeps,

horizontal polarization.

119
90

80

70

i" 60 5

m

2- 50

B 40

30

= 20

10

-10

\

:

iiyil k^II i im 1 1

i m"^TOiik 11 J, iJ i/i

iuM

Kl1iJii 1 1 D ifNwii

ihV SA

'"'H

{ r 1 lipm^i7''SiUfi/'M

1. . Ill jffu..

hMilw r

r^*i;nr

^

%i^W

m mm.

iF|r^

r'mw/

Vr

Meaisurerrient system; noise by eictemal attenuationfloor raise<j 10 dB

50 60 70

Frequency (MHz)

80 90

Figure A.36. MIST groundscreen, 50-90 MHz, 10 kHz IF bandwidth, 700 sweeps,

horizontal polarization.

90

80

70

"e 60 3

ffi S 50

£ 40

30

c 20

10

-10

Horjzontajly poljarizet] me^surerjient 4ntenria

1

i

1

' .J Ik Jli 1

A ll HI, 1 ill

y> III^ L

i

in'vii^^1

1 t\ J J ^

fli 1 ^f1r

Wfl 'A/'K>A 1 i"^ l\ 1 ^Ufj i iiiiKriA.

\

1 > i»

sy^^'yr 1rftfli( 1 "'Wiiyi

Measurerrient system inoise due to external attenuation

floor raised 10 d^

TT"' : r'

50 60 70

Frequency (MHz)

80 90

Figure A.37. Bldg. 1, Wing 4, 50-90 MHz, 10 kHz IF bandwidth, 2,100 sweeps,

horizontal polarization.

120
100

220

Frequency (MHz)

Figure A.38. Table Mountain NRQZ, 170-220 MHz, 10 kHz IF bandwidth, 2,300

sweeps, horizontal polarization.

MiiiMJ^ iM^»wifc,iioi«^f^ w'f^r V^i>*>^1HMf'^

170 180 190 200 210 220

Frequency (MHz)

Figure A.39. NIST groundscreen, 170-220 MHz, 100 kHz IF bandwidth, 700 sweeps,

horizontal polarization.

121
170 180 190 200

Frequency (MHz)

210 220

Figure A.40. Bldg. 1, Wing 4, 170-220 MHz, 100 kHz IF bandwidth, 2,100 sweeps,

horizontal polarization.

100

500 600 700 800

Frequency (MHz)

Figure A.41. Table Mountain NRQZ, 500-800 MHz, 100 kHz IF bandwidth, 2,300

sweeps, horizontal polarization.

122
100

90

80

70

S. 60

£ 50

CO

40

= 30

20

10

Measiiirement; systenrt noise floor by external attenuation

500 600 700 800

Frequency (MHz)

Figure A.42. NIST groundscreen, 500-800 MHz, 100 kHz IF bandwidth, 700 sweeps,

horizontal polarization.

100

S 60

B 50

S 30

Measurement: system; noise floor by external attenuation

500 600 700 800

Frequency (MHz)

Figure A.43. Bldg. 1, Wing 4, 500-800 MHz, 100 kHz IF bandwidth, 2,100 sweeps,

horizontal polarization.

123
124
APPENDIX B: MEASURED POWER LEVELS

In this appendix, the measured power levels are presented. These data were collected for

the following parameters. The receiving antenna was mounted on the measurement

vehicle. The antenna height was 2.96 m (9.68 ft) and had an antenna gain of 1.9 dBi

(1.55). At the Eldorado Mountain site, the transmitting antenna had a height of 3.66 m

(12.0 ft) and an antenna gain of L9 dBi (1.55), while at the Squaw Mountain location, the

transmitting antenna had a height of 8.20 m (26.91 ft) and an antenna gain of 6.5 dBi

(4.47). The input power at the antenna terminal was different for the two different sites

and different for the two frequencies. At the Eldorado Mountain site, the input power at the antenna terminal was 20.6 dBm (0.11 W) for the 533 MHz system and 28.6 dBm

(0.72 W) for the 772 MHz system. At the Squaw Mountain site, the input power at the

antenna terminal was 28.6 dBm (0.72 W) for the 533 MHz system and 37.0 dBm (5.0 W)

for the 772 MHz system.

B.l Measured Data for a Transmitter on Eldorado Mountain at 533 MHz.

At this location and frequency, the transmitter power level was 20.6 dBm (0.11 W) with an antenna height of 3.66 m (12.0 ft) and a gain of 1.9 dBi (1.55). The height of the

receiving antenna was 2.95 m (9.68 ft) with a gain of 1.9 dBi (1.55). Figures B.l through

B.IO present the measured power levels for various locations around the Boulder area.

-70.00

-80.00 —

-90.00 —

^ -100.00 —

110.00 —

120.00

Figure B.l. Measured power levels for different locations at the DOC Laboratories for

533 MHz from a transmitter on Eldorado Mountain. The results correspond to different

locations as the measurement vehicle was driven along various roads on the Laboratory

property.

125
70.00

120.00

Location

Figure B.2. Measured power levels at various locations on the Table Mountain NRQZ for

533 MHz from a transmitter on Eldorado Mountain. The results correspond to different

locations as the measurement vehicle was driven along the north-south road and the east- west road on the NRQZ.

80.00 —

B~ lOO.OO —

•120.00 —

Figure B.3. Measured power levels on the 28* Street route for 533 MHz from a

transmitter on Eldorado Mountain. These data were taken on 28* Street and on Highway 36 (from the DOC Laboratories to the Table Mountain NRQZ).

126
-70,00

-80.00 — -2

-90.00

E -100.00

5 -110.00 —

-120.00 —

-130.00 —

-140.00

Location

Figure B.4. Measured power levels on the Broadway loop for 533 MHz from a

transmitter on Eldorado Mountain. These measured data were taken on Highway 36 and

Highway 93, starting at the Table Mountain NRQZ going to Highway 72, and returning

to the DOC Laboratories.

-50.00

-60.00 —

-70.00 —

E -80.00

CO

o -90.00 —

•100.00 —

-110.00

•120.00 Location

Figure B.5. Measured power levels on the McCaslin loop for 533 MHz from a transmitter on Eldorado Mountain. These data were taken on various roads starting at a gas station at Eldorado Canyon and returning to the starting point.

127
50.00

•60.00

70 00— Broadway to NC A

E -80.00 —

I -90.00

100.00 —

110.00 —

120.00

TopofNCAR

NCAR to Broadway

Location

Figure B.6. Measured power levels at the NCAR facility at the top of Table Mesa for 533

MHz from a transmitter on Eldorado Mountain. These data were taken from the

intersection of Broadway and Table Mesa, to the top of Table Mesa to NCAR, and

returning to the Broadway-Table Mesa intersection.

70.00

80.00 —

-90.00

^ 100.00 —

110.00 —

120.00 1

Location

Figure B.7. Measured power levels on the Greenbriar loop for 533 MHz from a

transmitter on Eldorado Mountain, This loop consisted of Greenbriar Blvd., Lehigh

Street, Table Mesa Drive, and Gillaspie Drive.

128
-70.00

•120.00

Location

Figure B.8. Measured power levels in the Martin Acres neighborhood for 533 MHz from

a transmitter on Eldorado Mountain.

50.0

•60.0 —

•70.0 —

•80.0

•90.0 —

•100.0

•110.0

•120.0 —

•130.0 Location

Figure B.9. Measured power levels in Eldorado Canyon for 533 MHz from a transmitter on Eldorado Mountain.

129
-70.00

-80.00

— -90.00 —

-100.00 —

-110.00 —

-120.00

Location Figure B.IO. Measured power levels on County Road 67 for 533 MHz from a transmitter on Eldorado Mountain.

B.2 Measured Data for a Transmitter on Eldorado Mountain at 772 MHz.

At this location and frequency, the transmitter power level was 28.6 dBm (0.72 W) with an antenna height of 3.66 m (12.0 ft) and a gain of 1.9 dBi (1.55). The height of the

receiving antenna was 2.95 m (9.68 ft) with a gain of 1.9 dBi (1.55). Figures B.ll

through B.20 present the measured power levels for various locations around the Boulder

area.

130
•70.00

•110.00 —

•120.00 Location

Figure B.ll. Measured power levels for various locations at the DOC Laboratories for

772 MHz from a transmitter on Eldorado Mountain. The results correspond to different

locations as the measurement vehicle was driven along various roads on the Laboratory

property.

•70.00

-120.00

Figure B.12. Measured power levels at various locations on the Table Mountain NRQZ

for 772 MHz from a transmitter on Eldorado Mountain. The results correspond to different locations as the measurement vehicle was driven along the north-south road and

the east-west road on the NRQZ.

131
70.00

•80.00

•90.00 —

100.00 —

-110.00 —

•120.00 —

DOC toHwy. 36on 28th Street

-130.00 —4

Hwy.36 to Table Mtn.

Location

Figure B.13. Measured power levels on the 28* Street route for 772 MHz from a

transmitter on Eldorado Mountain. These data were taken on 28* Street to Highway 36

(from the DOC Laboratories to the Table Mountain NRQZ).

B

CQ

50.00

70.00

80.00 —

90.00 —

100.00

110.00 —

120.00 —

•130.00 —

•140.00 Location

Figure B.14 Measured power levels on the Broadway loop for 772 MHz from a

transmitter on Eldorado Mountain. These measured data were taken on Highway 36 and

Highway 93, starting at the Table Mountain NRQZ going to Highway 72, and returning

to the DOC Laboratories.

132
50.00

-120.00 Location

Figure B.15. Measured power levels on the McCaslin loop for 772 MHz from a

transmitter on Eldorado Mountain. These data were taken on various roads starting at a

gas station at Eldorado Canyon and returning to the starting point.

•50.00

•60.00 —

•70.00 Broadway to NCAR

•100.00 —

•110.00 —

•120.00

NCAR to Broadway

Location

Figure B.16. Measured power levels at the NCAR facility at the top of Table Mesa for

772 MHz from a transmitter on Eldorado Mountain. These data were taken from the

intersection of Broadway and Table Mesa, to the top of Table Mesa to NCAR, and

returning to the Broadway-Table Mesa intersection.

133
B

CO

70.00

•80.00 —

•90.00

•100.00 —

110.00

Location

Figure B,17. Measured power levels on the Greenbriar loop for 772 MHz from a

transmitter on Eldorado Mountain. This loop consisted of Greenbriar Blvd., Lehigh

Street, Table Mesa Drive, and Gillaspie Drive.

•60.00

80.00

B

09

100.00 —

120.00

Location

Figure B.18. Measured power levels in the Martin Acres neighborhood for 772 MHz

from a transmitter on Eldorado Mountain.

134
E

•50.0

•60.0 —

•70.0 —

•80.0

•90.0

•100.0 —

110.0

•120.0 —

130.0

Location Figure B.19. Measured power levels in Eldorado Canyon for 772 MHz from a transmitter on Eldorado Mountain.

•70.00

•80.00

— -90.00 E

•100.00 —

•110.00 —

•120.00

County Road 67

Figure B.20. Measured power levels on County Road 67 for 772 MHz from a transmitter on Eldorado Mountain.

135
B.3 Measured Data for a Transmitter on Squaw Mountain at 533 MHz.

At this location and frequency, the transmitter power level was 28.6 dBm (0.72 W) with

an antenna height of 8.20 m (26.91 ft) and a gain of 6.5 dBi (4.47). The height of the

receiving antenna was 2.95 m (9.68 ft) with a gain of 1.9 dBi (1.55). Figures B.21

through B.27 present the measured power levels for various locations around the Boulder

area.

•110.00

-120.00 —

03~ -130.00 —

140.00

-150.00

Location

Figure B.21. Measured power levels for various locations at the DOC Laboratories for

533 MHz from a transmitter on Squaw Mountain. The results correspond to different

locations as the measurement vehicle was driven along various roads on the Laboratory

property.

136
•104.00

124.00

Figure B.22. Measured power levels at different locations on the Table Mountain NRQZ

for 533 MHz from a transmitter on Squaw Mountain. The results correspond to different

locations as the measurement vehicle was driven along the north-south road and the east- west road on the NRQZ.

90.00

100.00 —

03t: -110.00 —

120.00 —

130.00

Location Figure B.23. Measured power levels on the 28^^ Street route for 533 MHz from a

transmitter on Squaw Mountain. These data were taken on 28* Street to Highway 36

(from the DOC Laboratories to the Table Mountain NRQZ).

137
•70.00

80.00 — -^

•90.00 —

= •100.00 —

•110.00 —

•120.00

•130.00 —

•140.00

Location

Figure B.24. Measured power levels on the Broadway loop for 533 MHz from a

transmitter on Squaw Mountain. These data were taken on Highway 36 and Highway 93,

starting at the Table Mountain NRQZ, going to Highway 72, and returning to the DOC

Laboratories.

•70.00

•80.00

•90.00 —

•100.00 —

•110.00

•120.00 —

•130.00 —

•140.00 Location Figure B.25. Measured power levels on the Golden loop for 533 MHz from a transmitter on Squaw Mountain. These data were taken in Golden, Colorado returning to the DOC

Laboratories via Indiana Ave.

138
-60.00

•70.00

•80.00 —

e -90.00

CQ

•100.00

110.00

•120.00

130.00

Location

Figure B.26. Measured power levels on the McCaslin loop for 533 MHz from a

transmitter on Squaw Mountain. These data were taken on various roads starting at a gas

station at Eldorado Canyon and returning to the starting point.

-100.00

-105.00 —

— -110.00 E

09

^ 115.00 —

-120.00 —

-125.00 1

Location

Figure B.27. Measured power levels on the Greenbriar loop for 533 MHz from a

transmitter on Squaw Mountain. This loop consisted of Greenbriar Blvd., Lehigh Street,

Table Mesa Drive, and Gillaspie Drive.

139
B.4 Measured Data for a Transmitter on Squaw Mountain at 772 MHz.

At this location and frequency, the transmitter power level was 37.0 dBm (5.0 W) with an antenna height of 8.20 m (26.91 ft) and a gain of 6.5 dBi (4.47). The height of the

receiving antenna was 2.95 m (9.68 ft) with a gain of 1.9 dBi (1.55). Figures B.28

through B.34 present the measured power levels for various locations around the Boulder

area.

100.00

120.00 —

140.00 —

160.00

Location

Figure B.28. Measured power levels for various locations at the DOC Laboratories for

772 MHz from a transmitter on Squaw Mountain. The results correspond to different

locations as the measurement vehicle was driven along various roads on the Laboratory

property.

140
•100.00

105.00 —

•120.00 —

-125.00 —

—j

1

1 11

1

1

1

1

1 1 r

Location

Figure B.29. Measured power levels at various locations on the Table Mountain NRQZ

for 772 MHz from a transmitter on Squaw Mountain. The results correspond to different

locations as the measurement vehicle was driven around the north-south road and the

east-west road on the NRQZ.

aa

•90.00

•100.00 —

-110.00

•120.00 —

-130.00 Location

)th Figure B.30. Measured power levels on the 28" Street route for 772 MHz from a

transmitter on Squaw Mountain. These data were taken on 28* Street to Highway 36

(from the DOC Laboratories to the Table Mountain NRQZ).

141
•70.00

•80.00 — •?

•90.00 —

E -100.00 —

S -110.00 —

•120.00

130.00 —

•140.00 Location Figure B.31. Measured power levels on the Broadway loop for 772 MHz from a

transmitter on Squaw Mountain. These data were taken on Highway 36 and Highway 93,

starting at the Table Mountain NRQZ, going to Highway 72, and returning to the DOC

Laboratories.

Em

•60.00

•70.00 —

•80.00

•90.00 —

•100.00

•110.00

-120.00 —

-130.00 —

•140.00 Location

Figure B.32. Measured power levels on the Golden loop for 772 MHz from a transmitter on Squaw Mountain. These measured data were taken in Golden, Colorado returning to the DOC Laboratories via Indiana Ave.

142
3U.UU

oo ~ >s co r^ "rt b: _ 60.00 — T3

OS 2

-a

TOo

CO

3= b. c

o >

o CQ

eg o

cr "« > ^

03 n^ •70.00 —

O

o a:

4) S

80.00 — s ETopof NCAR 90.00 — J ,ii 1

\

•100.00 - k

ili JIliU

-110.00 - 1

i1 if liiylMd1^

120.00 — r f| r

1 I ^w^^"Tfnn

lou.uu 1 ^n f\r\ ~~^

1

1

' 1

' 1

'

1

' I'M 1

' Location

Figure B.33. Measured power levels on the McCaslin loop for 772 MHz from a

transmitter on Squaw Mountain. These data were taken on various roads starting at a gas

station at Eldorado Canyon and returning to the starting point.

90.00

95.00

130.00

Location

Figure B.34. Measured power levels on the Greenbriar loop for 772 MHz from a

transmitter on Squaw Mountain. This loop consisted of Grreenbriar Blvd., Lehigh Street,

Table Mesa Drive, and Gillaspie Drive.

143
NTIA FORMAL PUBLICATION SERIES

NTIA CONTRACTOR REPORT

Information generated under an NTIA contract or grant and considered an

important contribution to existing knowledge.

NTIA HANDBOOK

Information pertaining to technical procedures, reference and data guides, and

formal user's manuals that are expected to be pertinent for a long time.

NTIA MONOGRAPH

A scholarly, professionally oriented publication dealing with state-of-the-art

research or an authoritative treatment of a broad area. A monograph is expected to have a long lifespan.

NTIA REPORT

Important contributions to existing knowledge but of less breadth than a monograph, such as results of completed projects and major activities, specific

major accomplishments, or NTIA-coordinated activities.

NTIA RESTRICTED REPORT

Contributions that fit the NTIA Report classification but that are limited in distribution because of national security classification or Departmental

constraints. This material receives full review and quality control equivalent to

the open-literature report series.

NTIA SPECIAL PUBLICATION

Information dehved from or of value to NTIA activities such as conference

proceedings, bibliographies, selected speeches, course and instructional

materials, and directories.

SPONSOR-ISSUED REPORTS

NTIA authors occasionally produce reports issued under an other-agency

sponsor's cover. These reports generally embody the criteria of the NTIA Report

series.

For information about NTIA publications, contact the ITS Technical Publications Office at

325 Broadway, Boulder, CO, 80305 Tel. (303) 497-3572 or e-mail luebs@its.bldrdoc.gov.

This report is for sale by the National Technical Information Service, 5285 Port Royal

Road, Springfield, VA 221 61, Tel. (800) 553-6847.
NISTTechnical Publications

Periodical

Journal of Research of the National Institute of Standards and Technology—Reports NIST research and development in those disciplines of the physical and engineering sciences in which the Institute is active. These include physics, chemistry, engineering, mathematics, and computer sciences. Papers cover a broad range of subjects, with major emphasis on measurement methodology and the basic technology

underlying standardization. Also included from time to time are survey articles on topics closely related to the Institute's technical and scientific programs. Issued six times a year.

Nonperiodicals

Monographs—Major contributions to the technical literature on various subjects related to the

Institute's scientific and technical activities. Handbooks—Recommended codes of engineering and industrial practice (including safety codes) devel- oped in cooperation with interested industries, professional organizations, and regulatory bodies. Special Publications—Include proceedings of conferences sponsored by NIST, NIST annual reports, and

other special publications appropriate to this grouping such as wall charts, pocket cards, and bibliographies.

National Standard Reference Data Series—Provides quantitative data on the physical and chemical

properties of materials, compiled from the world's literature and critically evaluated. Developed under a worldwide program coordinated by NIST under the authority of the National Standard Data Act (Public

Law 90-396). NOTE: The Journal of Physical and Chemical Reference Data (JPCRD) is published

bimonthly for NIST by the American Chemical Society (ACS) and the American Institute of Physics (AIP).

Subscriptions, reprints, and supplements are available from ACS, 1155 Sixteenth St., NW, Washington, DC

20056.

Building Science Series—Disseminates technical information developed at the Institute on building

materials, components, systems, and whole structures. The series presents research results, test methods, and

performance criteria related to the structural and environmental functions and the durability and safety

characteristics of building elements and systems.

Technical Notes—Studies or reports which are complete in themselves but restrictive in their treatment of

a subject. Analogous to monographs but not so comprehensive in scope or definitive in treatment of the subject area. Often serve as a vehicle for final reports of work performed at NIST under the sponsorship of

other government agencies.

Voluntary Product Standards—Developed under procedures published by the Department of Commerce

in Part 10, Tide 15, of the Code of Federal Regulations. The standards establish nationally recognized

requirements for products, and provide all concerned interests with a basis for common understanding of

the characteristics of the products. NIST administers this program in support of the efforts of private-sector

standardizing organizations.

Order the following NIST publications—FIPS and NISTIRs—from the National Technical Information

Service, Springfield, VA 22161.

Federal Information Processing Standards Publications (FTPS PUB)—Publications in this series

collectively constitute the Federal Information Processing Standards Register. The Register serves as the

official source of information in the Federal Government regarding standards issued by NIST pursuant to the Federal Property and Administrative Services Act of 1949 as amended. Public Law 89-306 (79 Stat. 1127), and as implemented by Executive Order 11717 (38 FR 12315, dated May 11, 1973) and Part 6 of

Title 15 CFR (Code of Federal Regulations).

NIST Interagency or Internal Reports (NIS'llK)—^The series includes interim or final reports on work

performed by NIST for outside sponsors (both government and nongovernment). In general, initial distribution is handled by the sponsor; public distribution is handled by sales through the National Technical

Information Service, Springfield, \A 22161, in hard copy, electronic media, or microfiche form. NISTIR's

may also report results of NIST projects of transitory or limited interest, including those that will be

published subsequently in more comprehensive form.
I
:f;

•'i^v;l Iv/

^M

V ^'

? . i ? ^?,,

-'"'Ha :P-'-