Attachment NWM-16 RadHaz

This document pretains to SES-MFS-20130604-00470 for Modification w/ Foreign Satellite (earth station) on a Satellite Earth Station filing.

IBFS_SESMFS2013060400470_999121

                                                   Radiation Hazard Analysis



                                                             11.1 Meter NWM-16
                                                            Bristow, Virginia 20136

            Introduction
            A radiation hazard anaylsis is presented for a 11.1 meter C band aperture antenna to be installed in
            BristowVirginia at the SES Washington Mediaport. This Radiation Analysis calculates the non-ionizing radiation
            levels expected to be emitted from the earth station on a worse cases basis and is performed in accordance with the
            Federal Communications Commissions Office of Engineering and Technology (OET) Bulletin, No. 65.



            Requirements
            OET 65 outlines the maximum permissible exposure limits in two cases for operation in this frequency range.

               1. The first case is the maximum level that a person may be exposed to in the general population. The exposure
                  limit is defined as a non-ionizing power level equal to 1 milliwatt per centimeter squared averaged over a
                  thirty minute period.
               2. The second case is a controlled environment where the maximum permissible exposure limit must not exceed
                  5 milliwatts per centimeter squared averaged over any six minute period.

            Summary
            The results indicate that no significant hazard will be presented to the general population and will be fully mitigated
            in the controlled area by the use of procedures that require the removal of transmit power before accessing the area
            around the main reflector.


            Analysis
            This analysis was performed on seven zones with the results shown in Radiation Hazard Zones. The Table labeled
            Input Values provides the - input data required to perform the analysis. The table labeled OET 65 Calculated
            Values provides the intermediate calculation used to perform the assessment in accordance with OET 65. The
            Analysis is performed for each a the each of seven radiation zones as shown in figure 1 – Analysis Zones. These
            zones are:
               1. Point between the feed and the sub-reflector
               2. The power at the surface of the antenna
               3. The power level between the main reflector and ground
               4. The near-field or Fresnel region in which the maxima can be reached before the field starts to diminish with
                  distance
               5. The Transition region where power begins to decrease inversely with distance from the antenna
               6. The Far Field or Fraunhofer region where power decreases inversely with the square of the distance. This is
                  the point at which the antenna beam is fully collimated
               7. The off axis level in the near field. This is defined as the area outside of the main beam removed and at least
                  one antenna diameter removed from the main beam




Generated 12/13/2012                                                1 of 2                                  NWM-16 11m C rad haz auto report


                                                       Radiation Hazard Analysis



                                     Operator:             SES
                          Location Designation:            Washington Mediaport              FCC Callsign:
                                       County:             Prince William                         SES ID: NWM-16
                                         Town:             Bristow                                   STA:
                                     State/Zip:            Virginia       20136
                       Input Values                             Value         Unit                             Band          Frequency
                           D = Aperture Diameter               11.10            Meters                          L             1000-2000
                        d = Subreflector Diameter               1.37            Meters                          S             2000-4000
                               G = Antenna Gain                 55.6                dBi                         C             4000-8000
                                FCC Designation                  C              Band                            X            8000-12500
                                   F = Frequency               6.175            GHz                             Ku          12500-18000
                     P = Transmitter Power Watts:               350             Watts                           K           18000-25500
               R ua = closest point to uncontrolled area         20            meters                           Ka          26500-40000
               Elevation angle at closest point R ua             10            Degrees                          O           40000-50000
                                     Height (AGL)               3.47           meters                           V           50000-75000

               OET 65 Calculated Values                      Formula            Value            Unit
                                                                 c
                                     λ= Wavelength                              0.0486     meters
                                                                 F
                                                                 (G/10)
                                G = Antenna Gain              10             363078.0548   (W) linear
                                                              Gλ2/4π
                        η = Apperture Efficiency                                    70%    percentage
                                                               πD2/4
                             A = Area of reflector              πR2              96.769    meters 2
                          a = area of subreflector               πr2          14741.138    cm 2
                                                                 D2             634.441    meters
                        R nf = Near-Field Region
                                                                 4λ               110      Meters AGL
                                                                >Rnf            634.441    >meters
                          R t = Transition Region
                                                                <Rff           1522.659    <meters
                          R ff = Far Field Region              0.6D2           1522.659    meters
                                                                  λ               264      Meters AGL

                                                                                                                   Exposure Limits
            Radiation Analysis Zone                          Formula            Level           Value     General Public   Occupational
                                                                                                           <1mW/cm2     <5mW/cm2
                                                                 4P                                       >FCC MPE See >FCC MPE See
    1                          Power Subreflector                               94.972         mW/cm2
                                                                  a                                          Note 1       Note 2
                                                                 4P                                       >FCC MPE See
    2                             Antenna Surface                               1.447          mW/cm2                   <FCC MPE
                                                                  A                                          Note 1
                                                                 P
    3                    Main Reflector Ground                                  0.362          mW/cm2       <FCC MPE         <FCC MPE
                                                                  A
                                                                4η P                                      >FCC MPE See
    4           S nf =Near-Field Power Density                                  1.018          mW/cm2                        <FCC MPE
                                                                  A                                          Note 1
                                                                                                          >FCC MPE See
    5       S t = Max Transition Power Density                  < Snf           1.018          mW/cm2                        <FCC MPE
                                                                                                             Note 1
                                                                 PG
    6        S ff = Max Far field Power Density                                 0.436          mW/cm2       <FCC MPE         <FCC MPE
                                                               4πRff2
    7          Off Access Level Near Field                   Snf - 20 dB       0.01018         mW/cm2       <FCC MPE         <FCC MPE

  Notes
     1. The antenna is installed in a controlled location access is restricted to authorized personnel only. The antenna is
          marked with RF Radiation Hazard signage.
     2. Inside the controlled area, MPE levels exceed the MPE exposure for occupational levels. The levels will be reduced
          to safe MPE by removing power to the transmitters when work is performed on or around the antenna. This area
          can only be accessed by qualified personnel.
     3. The field develops 3.47 meters above ground level at the minimum elevation angle which is not accessable to the
          general public.




Generated 12/13/2012                                                       2 of 2                       NWM-16 11m C rad haz auto report



Document Created: 2012-12-13 11:09:22
Document Modified: 2012-12-13 11:09:22

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