Attachment GSM-2 RadHaz

This document pretains to SES-MOD-20160317-00260 for Modification on a Satellite Earth Station filing.

IBFS_SESMOD2016031700260_1130231

                                                                                         Exhibit C
Radiation Hazard Report                                                                  Page 1 of 5


      Analysis of Non-Ionizing Radiation for a 9.1-Meter Earth
                          Station System
This report analyzes the non-ionizing radiation levels for a 9.1-meter earth station system. The analysis and
calculations performed in this report comply with the methods described in the FCC Office of Engineering
and Technology Bulletin, No. 65 first published in 1985 and revised in 1997 in Edition 97-01. The radiation
safety limits used in the analysis are in conformance with the FCC R&O 96-326. Bulletin No. 65 and the
FCC R&O specifies that there are two separate tiers of exposure limits that are dependant on the situation in
which the exposure takes place and/or the status of the individuals who are subject to the exposure. The
Maximum Permissible Exposure (MPE) limits for persons in a General Population/Uncontrolled environment
are shown in Table 1. The General Population/Uncontrolled MPE is a function of transmit frequency and is
for an exposure period of thirty minutes or less. The MPE limits for persons in an Occupational/Controlled
environment are shown in Table 2. The Occupational MPE is a function of transmit frequency and is for an
exposure period of six minutes or less. The purpose of the analysis described in this report is to determine
the power flux density levels of the earth station in the far-field, near-field, transition region, between the
subreflector or feed and main reflector surface, at the main reflector surface, and between the antenna edge
and the ground and to compare these levels to the specified MPEs.


                Table 1. Limits for General Population/Uncontrolled Exposure (MPE)
                   Frequency Range (MHz)            Power Density (mW/cm2)
                           30-300                                0.2
                          300-1500                    Frequency (MHz)*(0.8/1200)
                        1500-100,000                             1.0

                     Table 2. Limits for Occupational/Controlled Exposure (MPE)
                   Frequency Range (MHz)            Power Density (mW/cm2)
                           30-300                                1.0
                          300-1500                    Frequency (MHz)*(4.0/1200)
                        1500-100,000                             5.0


          Table 3. Formulas and Parameters Used for Determining Power Flux Densities
     Parameter                       Symbol            Formula                   Value            Units
     Antenna Diameter                   D                Input                     9.1            m
     Antenna Surface Area             Asurface          π D2 / 4                  65.04           m2
     Subreflector Diameter             Dsr               Input                    122.0           cm
     Area of Subreflector              Asr              π Dsr 2/4              11689.87           cm2
     Frequency                          F                Input                    6175            MHz
     Wavelength                         λ               300 / F                0.048583           m
     Transmit Power                     P                Input                   750.00           W
     Antenna Gain (dBi)                Ges               Input                    53.9            dBi
     Antenna Gain (factor)              G               10Ges/10               245470.9           n/a
     Pi                                 π              Constant                3.1415927          n/a
     Antenna Efficiency                 η              Gλ2/(π2D2)                 0.71            n/a


                                                                                  Exhibit C
Radiation Hazard Report                                                           Page 2 of 5



1.      Far Field Distance Calculation

The distance to the beginning of the far field can be determined from the following equation:

     Distance to the Far Field Region                       Rff = 0.60 D2 / λ                   (1)
                                                                = 1022.7 m

The maximum main beam power density in the far field can be determined from the following
equation:

     On-Axis Power Density in the Far Field                 Sff = G P / (4 π Rff 2)             (2)
                                                                = 14.007 W/m2
                                                                = 1.401 mW/cm2

2.      Near Field Calculation

Power flux density is considered to be at a maximum value throughout the entire length of the
defined Near Field region. The region is contained within a cylindrical volume having the same
diameter as the antenna. Past the boundary of the Near Field region, the power density from the
antenna decreases linearly with respect to increasing distance.

The distance to the end of the Near Field can be determined from the following equation:

     Extent of the Near Field                               Rnf = D2 / (4 λ)                    (3)
                                                                = 426.1 m

The maximum power density in the Near Field can be determined from the following equation:

     Near Field Power Density                               Snf = 16.0 η P / (π D2)             (4)
                                                                = 32.699 W/m2
                                                                = 3.270 mW/cm2

3.      Transition Region Calculation

The Transition region is located between the Near and Far Field regions. The power density
begins to decrease linearly with increasing distance in the Transition region. While the power
density decreases inversely with distance in the Transition region, the power density decreases
inversely with the square of the distance in the Far Field region. The maximum power density in
the Transition region will not exceed that calculated for the Near Field region. The power density
calculated in Section 1 is the highest power density the antenna can produce in any of the regions
away from the antenna. The power density at a distance Rt can be determined from the following
equation:

     Transition Region Power Density                        St = Snf Rnf / Rt                   (5)
                                                               = 3.270 mW/cm2


                                                                              Exhibit C
Radiation Hazard Report                                                       Page 3 of 5



4.      Region between the Main Reflector and the Subreflector

Transmissions from the feed assembly are directed     toward the subreflector surface, and are
reflected back toward the main reflector. The most    common feed assemblies are waveguide
flanges, horns or subreflectors. The energy between   the subreflector and the reflector surfaces
can be calculated by determining the power density    at the subreflector surface. This can be
determined from the following equation:

     Power Density at the Subreflector                    Ssr = 4000 P / Asr                (6)
                                                              = 256.633 mW/cm2


5.      Main Reflector Region

The power density in the main reflector is determined in the same manner as the power density at
the subreflector. The area is now the area of the main reflector aperture and can be determined
from the following equation:

     Power Density at the Main Reflector Surface      Ssurface = 4 P / Asurface             (7)
                                                               = 46.126 W/m2
                                                               = 4.613 mW/cm2


6.      Region between the Main Reflector and the Ground

Assuming uniform illumination of the reflector surface, the power density between the antenna and
the ground can be determined from the following equation:

     Power Density between Reflector and Ground           Sg = P / Asurface                 (8)
                                                             = 11.532 W/m2
                                                             = 1.153 mW/cm2


                                                                             Exhibit C
Radiation Hazard Report                                                      Page 4 of 5



7.     Summary of Calculations

          Table 4. Summary of Expected Radiation levels for Uncontrolled Environment

                                            Calculated Maximum
                                        Radiation Power Density Level
Region                                             (mW/cm2)                Hazard Assessment
1. Far Field (Rff = 1022.7 m)                  Sff      1.401                Potential Hazard
2. Near Field (Rnf = 426.1 m)                  Snf      3.270                Potential Hazard
3. Transition Region (Rnf < Rt < Rff)          St       3.270                Potential Hazard
4. Between Main Reflector and                  Ssr    256.633                Potential Hazard
    Subreflector
5. Main Reflector                               Ssurface   4.613             Potential Hazard
6. Between Main Reflector and Ground            Sg         1.153             Potential Hazard




           Table 5. Summary of Expected Radiation levels for Controlled Environment

                                            Calculated Maximum
                                           Radiation Power Density
Region                                         Level (mW/cm2)             Hazard Assessment
1. Far Field (Rff = 1022.7 m)                  Sff       1.401             Satisfies FCC MPE
2. Near Field (Rnf = 426.1 m)                  Snf       3.270             Satisfies FCC MPE
3. Transition Region (Rnf < Rt < Rff)          St        3.270             Satisfies FCC MPE
4. Between Main Reflector and                  Ssr     256.633              Potential Hazard
    Subreflector
5. Main Reflector                               Ssurface   4.613           Satisfies FCC MPE
6. Between Main Reflector and Ground            Sg         1.153           Satisfies FCC MPE




It is the applicant's responsibility to ensure that the public and operational personnel are not
exposed to harmful levels of radiation.


                                                                                      Exhibit C
Radiation Hazard Report                                                               Page 5 of 5



8.     Conclusions

Based upon the above analysis, it is concluded that harmful levels of radiation may exist in those
regions noted for the Uncontrolled (Table 4) Environment.

The antenna will be installed at Globecomm License Sub LLC’s teleport facility in Laurel,
Maryland. The teleport is a gated and fenced facility with secured access in and around the
proposed antenna. The earth station will be marked with the standard radiation hazard warnings,
as well as the area in the vicinity of the earth station to inform those in the general population, who
might be working or otherwise present in or near the direct path of the main beam.

The applicant will ensure that the main beam of the antenna will be pointed at least one diameter
away from any building, or other obstacles in those areas that exceed the MPE levels. Since one
diameter removed from the center of the main beam the levels are down at least 20 dB, or by a
factor of 100, these potential hazards do not exist for either the public, or for earth station
personnel.

Finally, the earth station’s operating personnel will not have access to areas that exceed the MPE
levels, while the earth station is in operation. The transmitter will be turned off during periods of
maintenance, so that the MPE standard of 5.0 mw/cm**2 will be complied with for those regions in
close proximity to the main reflector, which could be occupied by operating personnel.

The applicant agrees to abide by the conditions specified in Condition 5208 provided below:

       Condition 5208 - The licensee shall take all necessary measures to ensure that the
       antenna does not create potential exposure of humans to radiofrequency radiation
       in excess of the FCC exposure limits defined in 47 CFR 1.1307(b) and 1.1310
       wherever such exposures might occur. Measures must be taken to ensure
       compliance with limits for both occupational/controlled exposure and for general
       population/uncontrolled exposure, as defined in these rule sections. Compliance
       can be accomplished in most cases by appropriate restrictions such as fencing.
       Requirements for restrictions can be determined by predictions based on
       calculations, modeling or by field measurements. The FCC's OET Bulletin 65
       (available on-line at www.fcc.gov/oet/rfsafety) provides information on predicting
       exposure levels and on methods for ensuring compliance, including the use of
       warning and alerting signs and protective equipment for worker.



Document Created: 2016-03-16 15:52:14
Document Modified: 2016-03-16 15:52:14

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