Attachment NWM-17 RadHaz

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

IBFS_SESMFS2013060400470_999122

Radiation Hazard Analysis 9 Meter NWM-17 Bristow, Virginia 20136 Introduction A radiation hazard anaylsis is presented for a 9 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-17 9m C rad haz auto report

Radiation Hazard Analysis Operator: SES Location Designation: Washington Mediaport FCC Callsign: County: Prince William SES ID: NWM-17 Town: Bristow STA: State/Zip: Virginia 20136 Input Values Value Unit Band Frequency D = Aperture Diameter 9.00 Meters L 1000-2000 d = Subreflector Diameter 0.94 Meters S 2000-4000 G = Antenna Gain 53.6 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 229086.7653 (W) linear Gλ2/4π η = Apperture Efficiency 68% percentage πD2/4 A = Area of reflector πR2 63.617 meters 2 a = area of subreflector πr2 6939.778 cm 2 D2 417.091 meters R nf = Near-Field Region 4λ 72 Meters AGL >Rnf 417.091 >meters R t = Transition Region <Rff 1001.017 <meters R ff = Far Field Region 0.6D2 1001.017 meters λ 174 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 201.736 mW/cm2 a Note 1 Note 2 4P >FCC MPE See 2 Antenna Surface 2.201 mW/cm2 <FCC MPE A Note 1 P 3 Main Reflector Ground 0.550 mW/cm2 <FCC MPE <FCC MPE A 4η P >FCC MPE See 4 S nf =Near-Field Power Density 1.486 mW/cm2 <FCC MPE A Note 1 >FCC MPE See 5 S t = Max Transition Power Density < Snf 1.486 mW/cm2 <FCC MPE Note 1 PG 6 S ff = Max Far field Power Density 0.637 mW/cm2 <FCC MPE <FCC MPE 4πRff2 7 Off Access Level Near Field Snf - 20 dB 0.01486 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-17 9m C rad haz auto report


Document Created: 2012-12-13 11:10:59
Document Modified: 2012-12-13 11:10:59
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