Attachment RadHaz

This document pretains to SES-LIC-20121009-00905 for License on a Satellite Earth Station filing.

IBFS_SESLIC2012100900905_970115

                                                                                  Exhibit B
Radiation Hazard Report                                                           Page 1 of 5


     Analysis of Non-Ionizing Radiation for a 1.35-Meter Earth
                          Station System
This report analyzes the non-ionizing radiation levels for a 1.35-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                   1.35         m
     Antenna Surface Area          Asurface         π D2 / 4                 1.43         m2
     Subreflector Diameter          Dsr              Input                   19.0         cm
     Area of Subreflector           Asr             π Dsr 2/4              283.53         cm2
     Frequency                       F               Input                  14250         MHz
     Wavelength                      λ              300 / F               0.021053        m
     Transmit Power                  P               Input                  90.00         W
     Antenna Gain (dBi)             Ges              Input                   44.3         dBi
     Antenna Gain (factor)           G              10Ges/10              26915.3         n/a
     Pi                              π             Constant              3.1415927        n/a
     Antenna Efficiency              η             Gλ2/(π2D2)                0.66         n/a


                                                                                  Exhibit B
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)
                                                                = 51.9 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)
                                                                = 71.451 W/m2
                                                                = 7.145 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)
                                                                = 21.6 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)
                                                                = 166.798 W/m2
                                                                = 16.680 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)
                                                               = 16.680 mW/cm2


                                                                              Exhibit B
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)
                                                              = 1269.713 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)
                                                               = 251.504 W/m2
                                                               = 25.150 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)
                                                             = 62.876 W/m2
                                                             = 6.288 mW/cm2


                                                                               Exhibit B
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 = 51.9 m)                     Sff         7.145             Potential Hazard
2. Near Field (Rnf = 21.6 m)                    Snf        16.680             Potential Hazard
3. Transition Region (Rnf < Rt < Rff)           St         16.680             Potential Hazard
4. Between Main Reflector and                   Ssr      1269.713             Potential Hazard
    Subreflector
5. Main Reflector                               Ssurface   25.150             Potential Hazard
6. Between Main Reflector and Ground            Sg          6.288             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 = 51.9 m)                    Sff         7.145             Potential Hazard
2. Near Field (Rnf = 21.6 m)                   Snf        16.680             Potential Hazard
3. Transition Region (Rnf < Rt < Rff)          St         16.680             Potential Hazard
4. Between Main Reflector and                  Ssr      1269.713             Potential Hazard
    Subreflector
5. Main Reflector                              Ssurface   25.150             Potential Hazard
6. Between Main Reflector and Ground           Sg          6.288             Potential Hazard

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



8.     Conclusions


Based on this analysis it is concluded that the FCC RF Guidelines have been exceeded in the
specific regions of Tables 1 and 2. The applicant proposes to comply with the Maximum
Permissible Exposure (MPE) limits of 1 mW/cm2 for the Uncontrolled areas and the MPE limits of
5 mW/cm2 for the Controlled areas by one or more of the following methods:


Means of Compliance Uncontrolled Areas

The antenna will be located on top of a truck. The bottom lip of the dish will be 3.00 meters above
ground level. The general public will not have access to areas within ½ diameter from the edge of
the antenna.


                                                                                      Exhibit B
Radiation Hazard Report                                                               Page 5 of 5


Since one diameter removed from the main beam of the antenna or ½ diameter removed from the
edge of the antenna the RF levels are reduced by a factor of 100 or 20 dB. None of the areas
exceeding the MPE levels will be accessible by the general public.

Radiation hazard signs will be posted while this earth station is in operation.

The applicant will ensure that no buildings or other obstacles will be in the areas that exceed the
MPE levels.



Means of Compliance Controlled Areas


The earth station’s operational personnel will not have access to the areas that exceed the MPE
levels while the earth station is in operation.

The transmitters will be turned off during antenna maintenance.


Means of Compliance - Safety in General

This antenna system is located on a mobile unit and conditions will vary from operating site to
operating site. Because of this, the licensee will establish procedures for the operational personnel
to verify that the antenna is not pointing in the direction of populated areas, and that access to
hazardous areas are restricted while the unit is in operation.

In addition, the transmit power used in these calculations is greater than that which will typically be
utilized by the earth station. During normal operation, the typical power level would generally not
exceed more than 50 to 75 percent of the indicated transmitter power. Maximum transmit power
would generally only occur in conditions of extreme inclement weather.

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: 2012-10-02 15:11:44
Document Modified: 2012-10-02 15:11:44

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