Attachment Exhibit A

This document pretains to SES-STA-20190426-00552 for Special Temporal Authority on a Satellite Earth Station filing.


                                                                                         Exhibit A

Radiation Hazard Report
Analysis of Non-Ionizing Radiation for a 1.2 m Earth Station
This analysis provides the calculated non-ionizing radiation levels for a 1.2-meter earth station system.

The methods and calculations performed in this analysis are based on the FCC Office of Engineering
and Technology Bulletin, No.65, October 1985 as 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 (Summarized in Annex 1).
There are separate exposure limits applicable to the General Population/Uncontrolled Environment and
the Occupational/Controlled Environment. The Maximum Permissible Exposure (MPE) limits for
persons in a General Population/Uncontrolled environment for the frequency band of this antenna, is 1
mW/cm2 for a 30 minute or lower time period as shown in Annex 1 (a). The MPE limit for persons in an
Occupational/Controlled environment for the frequency band of this antenna is 5 mW/cm2 for a 6
minute time or lower period as shown in Annex 1 (b). The purpose of this analysis described is to
determine the power flux density levels of the earth station at the main reflector surface, the near-field,
transition region, far-field, between the sub-reflector or feed and, at the main reflector surface, and
between the antenna edge and the ground and to compare these levels to the specified MPEs.


The parameters of the antenna that is the subject of this analysis are shown in Table 1.
Intermediate calculated values and constants are provided in Table 2.

 Table 1. Input Parameters Used for Determining Power Flux Densities
                 Parameter                     Symbol      Formula              Value           Units
Antenna Diameter                                  D         Input                 1.2             m
Frequency                                         F         Input               14100           MHz
Transmit Power                                    P         Input                 10             W
Antenna Gain (dBi)                               Ges        Input                43.3            dBi

 Table 2. Calculated Values and Constants
                 Parameter                         Symbol       Formula          Value          Units
                                                                     2
Antenna Surface Area                                Asurface          /4          1.13          m^2
Wavelength                                                        300/F        0.021277           m
                                                                    Ges/10
Antenna Gain (factor)                                 G          10            21379.62          n/a
Pi                                                              Constant      3.1415927          n/a
                                                                  2     2 2
Antenna Efficiency                                                       D)       0.68           n/a


1. Antenna Main Reflector Surface
The power density in the main reflector is determined from the Power level and the area of the main
reflector aperture. This is determined from the following equation:

              Power Density at the Main Reflector Surface:

                                            Ssurface = 4P/Asurface                        (1)
                                                                                  2
                                                                =    35.368   W/m
                                                                                    2
                                                                =    3.537    mW/cm

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 is determined
from the following equation:

                                   Extent of the Near Field:

                                                          2
                                                  Rnf = D                                 (2)
                                                                =    16.92    m

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

                                        Near Field Density:

                                                                2
                                      Snf                       )                         (3)
                                                                                      2
                                                                =    2.409    mW/cm

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 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 is determined from the following equation:

                          Transition Region Power Density:

                                                 St = Snf Rnf / Rt                        (4)
                                                                                      2
                                                                =    2.409    mW/cm


4. Far Field Distance Calculation
The distance to the Far Field Region is calculated using the following equation:

                               Distance to Far Field Region:

                                                             2
                                               Rff = 0.6 D                                         (5)
                                                                      =   40.608   m

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

                    On-axis Power Density in the Far Field:

                                                                      2
                                         Sff                     ff   )                            (6)
                                                                                           2
                                                                      =   1.032    mW/cm

5. Region between the Main Reflector and the Ground
Assuming uniform illumination of the reflector surface, the power density between the antenna and the
ground is determined from the following equation:

             Power Density between Reflector and Ground:

                                               Sg = P / Asurface                                   (7)
                                                                                               2
                                                              =           0.884        mW/cm


7. Summary of Calculations

 Table 3. Summary of Expected Radiation levels for Uncontrolled Environment
                                                                       Calculated
                                                                       Maximum
                                                                       Radiation
                                                                                      Hazard
                           Region                           Symbol       Power
                                                                                    Assessment
                                                                        Density
                                                                         Level
                                                                               2
                                                                       (mW/cm )
                                                                                      Potential
1. Main Reflector                                           Ssurface       3.537
                                                                                       Hazard
                                                                                      Potential
2. Near Field                         (Rnf =   16.92 m)       Snf          2.409
                                                                                       Hazard
                                                                                      Potential
3. Transition Region (Rnf <Rt< Rff)                           St           2.409
                                                                                       Hazard
                                                                                      Potential
4. Far Field                          (Rff =   40.61 m)       Sff          1.032
                                                                                       Hazard
                                                                                    Satisfies FCC
5. Between Main Reflector and Ground                          Sg           0.884
                                                                                         MPE

Table 4. Summary of Expected Radiation levels for Controlled Environment
                                                                       Calculated
                                                                       Maximum
                                                                       Radiation
                                                                                      Hazard
                           Region                           Symbol       Power
                                                                                    Assessment
                                                                        Density
                                                                         Level
                                                                               2
                                                                       (mW/cm )
                                                                                    Satisfies FCC
1. Main Reflector                                           Ssurface       3.537
                                                                                         MPE
                                                                                    Satisfies FCC
2. Near Field                         (Rnf =   16.92 m)       Snf          2.409
                                                                                         MPE
                                                                                    Satisfies FCC
3. Transition Region (Rnf <Rt< Rff)                           St           2.409
                                                                                         MPE
                                                                                    Satisfies FCC
4. Far Field                          (Rff =   40.61 m)       Sff          1.032
                                                                                         MPE
                                                                                    Satisfies FCC
5. Between Main Reflector and Ground                          Sg           0.884
                                                                                         MPE


harmful levels of radiation.


8. Conclusion
Based upon the above analysis, it is concluded that harmful levels of radiation may exist in those
regions noted for the Uncontrolled (Table 3) Environment and the Controlled Environment (Table 4).

The antenna is located in Seattle, WA.
The antenna is in a 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 area that exceed the MPE levels. Since one diameter
removed from the center of the main beam the levels are down by 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.



levels, while the earth station is in operation. The transmitter will be turned off during those periods of
                                                         2
maintenance, so that the MPE standard of 5.0 mW/cm will be complied with for those regions in close
proximity to the main reflector, which could be occupied by operating personnel.



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


                                   ANNEX 1
                                  (MPE Levels)

a) Limits for General Population/Uncontrolled Exposure (MPE)
         Frequency Range (MHz)                     Power Density (mW/cm2)
                 30-300                                      0.2
                300-1500                          Frequency(MHz)*(4.0/1200)
              1500-100,000                                    1

b) Limits for Occupational/Controlled Exposure (MPE)
                                                                          2
          Frequency Range (MHz)                     Power Density (mW/cm )
                   30-300                                     1
                  300-1500                         Frequency(MHz)*(4.0/1200)
                1500-100,000                                  5



Document Created: 2019-04-26 11:28:29
Document Modified: 2019-04-26 11:28:29

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