Attachment Annex 3 Rad Haz

This document pretains to SES-MOD-20160712-00641 for Modification on a Satellite Earth Station filing.

IBFS_SESMOD2016071200641_1142997

Annex 3 O3b Radiation Hazard Site Studies Two Radiation Hazard studies for the General Dynamics 2.4 meter antenna are provided on the following pages. O3b has conducted a radiation hazard study for transmissions in each of its contiguous transmission bands, 27.6-28.4 GHz and 28.6-29.1 GHz. The results of those studies are included in this annex. As noted in each study, O3b will take steps to mitigate the potential for harmful exposure to radiation frequency radiation in accordance with the Federal Communications Commission’s Office of Engineering and Technology (OET) Bulletin, No. 65.

Radiation Hazard Analysis 2.4 Meter - General Dynamics GSO 40 Manassas, Virginia 20109 Introduction A radiation hazard anaylsis is presented for a 2.4 meter Ka band aperture antenna to be installed in Manassas Virginia at the O3b Networks Global Operations Center. 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. The results of this is shown in Radiation Hazard Zones. The Table labeled Input Values provides the input data used 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 of the 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 2. Main Reflector 1.Subreflector 4.Near Field 5. Transition 6. Far Field 3. Main Reflector Ground 7.Off Axis Near Field Figure 1 – Analysis Zones Generated 06/18/2016 Page 1 of 2 Rad Haz Base file GD_1.8

Radiation Hazard Analysis Operator: O3b Networks Location Designation: Global Operations Center FCC ID: County: Prince William O3b ID: General Dynamics GSO 40 Town: Manassas STA: State/Zip: Virginia 20109 Input Values Value Unit Band Frequency GHz D = Aperture Diameter 2.4 Meters L 1000-2000 d = Subreflector Diameter 0.1 Meters S 2000-4000 = Apperture Efficeny 67% percentage C 4000-8000 FCC Designation Ka Band X 8000-12500 F = Frequency 27652 MHz Ku 12500-18000 P = Transmitter Power Watts: 40 Watts K 18000-25500 p = Number Transmitters: 1 Ka 26500-40000 Rua = closest point to uncontrolled area 20 meters O 40000-50000 Elevation angle at closest point Rua 7 Degrees V 50000-75000 OET 65 Calculated Values Formula Value Unit λ= Wavelength c/ F 0.0108 meters P 1= Total Antenna Input Power P*p 40 watts 4  A G = Antenna Gain G= 2 323271.31 linear  Antenna Gain dB 10 log10 G 55.1 dBi 2 D A = Area of reflector   4.52 meters2 22 d a = area of subreflector or feed   0.01 meters2 2 2 Rnf = Near-Field Region D 132.73 meters Rnf = 16 4 Meters AGL Transition Region > Rnf < R ff 132.73 >meters 2 318.55 <meters 0.6 D 318.55 meters Rff = Far Field Region R ff =  39 Meters AGL Exposure Limits Radiation Analysis Zone Formula Level Value General Public Occupational <1mW/cm2 <5mW/cm2 4 Pt >FCC MPE See >FCC MPE See 1 Power Subreflector a 2038.217 mW/cm2 Note 1 Note 2 4 Pt >FCC MPE See <FCC MPE 2 Antenna Surface A 3.539 mW/cm2 Note 1 Pt 3 Main Reflector Ground A 0.885 mW/cm2 <FCC MPE <FCC MPE 16  Pt Pt >FCC MPE See 4 Snf =Near-Field Power Density S nf = pi D 2 =4   A  4.742 mW/cm2 Note 1 <FCC MPE S nf R nf S t= >FCC MPE See 5 Max Transition Power Density Rnf 4.742 mW/cm2 Note 1 <FCC MPE PG S ff = t 2 >FCC MPE See 6 Max Far field Power Density 4 R 1.015 mW/cm2 Note 3 <FCC MPE 7 Off Access Level Near Field S ua =S nf −20dB 0.04742 mW/cm 2 <FCC MPE <FCC MPE Notes 1. The antenna is installed in a controlled location access is restricted to authorized personnel only. The area is marked with RF Radiation Hazard signage. Area not accessible to the general public. 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 far field develops 39 meters above ground level at the minimum elevation angle which is not accessable to the general public. Generated 06/18/2016 Page 2 of 2 Rad Haz Base file GD_1.8

Radiation Hazard Analysis 2.4 Meter - General Dynamics NGSO 40 Manassas, Virginia 20109 Introduction A radiation hazard anaylsis is presented for a 2.4 meter Ka band aperture antenna to be installed in Manassas Virginia at the O3b Networks Global Operations Center. 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. The results of this is shown in Radiation Hazard Zones. The Table labeled Input Values provides the input data used 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 of the 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 2. Main Reflector 1.Subreflector 4.Near Field 5. Transition 6. Far Field 3. Main Reflector Ground 7.Off Axis Near Field Figure 1 – Analysis Zones Generated 06/18/2016 Rad Haz Base file Page 1 of 2 O3b Engineering PGR

Radiation Hazard Analysis Operator: O3b Networks Location Designation: Global Operations Center FCC ID: County: Prince William O3b ID: General Dynamics NGSO 40 Town: Manassas STA: State/Zip: Virginia 20109 Input Values Value Unit Band Frequency GHz D = Aperture Diameter 2.4 Meters L 1000-2000 d = Subreflector Diameter 0.1 Meters S 2000-4000  =Apperture Efficeny 67% percentage C 4000-8000 FCC Designation Ka Band X 8000-12500 F = Frequency 28850 MHz Ku 12500-18000 P = Transmitter Power Watts: 40 Watts K 18000-25500 p = Number Transmitters: 1 Ka 26500-40000 Rua = closest point to uncontrolled area 20 meters O 40000-50000 Elevation angle at closest point R ua 7 Degrees V 50000-75000 OET 65 Calculated Values Formula Value Unit λ= Wavelength c/F 0.0104 meters P 1= Total Antenna Input Power P*p 40 watts 4  A G = Antenna Gain G= 2 351889.01 linear  Antenna Gain dB 10 log10 G 55.46 dBi 2 D A = Area of reflector   4.52 meters2 22 d a = area of subreflector or feed   0.01 meters2 2 2 Rnf = Near-Field Region D 138.48 meters Rnf = 17 4 Meters AGL Transition Region > Rnf < R ff 138.48 >meters 2 332.35 <meters 0.6 D 332.35 meters Rff = Far Field Region R ff =  41 Meters AGL Exposure Limits Radiation Analysis Zone Formula Level Value General Public Occupational <1mW/cm2 <5mW/cm2 4 Pt >FCC MPE See >FCC MPE See 1 Power Subreflector a 2038.217 mW/cm2 Note 1 Note 2 4 Pt >FCC MPE See <FCC MPE 2 Antenna Surface A 3.539 mW/cm2 Note 1 Pt 3 Main Reflector Ground A 0.885 mW/cm2 <FCC MPE <FCC MPE 16  Pt Pt >FCC MPE See 4 Snf =Near-Field Power Density S nf = pi D 2 =4  A  4.742 mW/cm2 Note 1 <FCC MPE S nf R nf S t= >FCC MPE See 5 Max Transition Power Density Rnf 4.742 mW/cm2 Note 1 <FCC MPE Pt G S ff = >FCC MPE See 6 Max Far field Power Density 4 R 2 1.015 mW/cm2 Note 3 <FCC MPE 7 Off Access Level Near Field S ua =S nf −20dB 0.04742 mW/cm 2 <FCC MPE <FCC MPE Notes 1. The antenna is installed in a controlled location access is restricted to authorized personnel only. The area is marked with RF Radiation Hazard signage. Area not accessible to the general public. 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 far field develops 41 meters above ground level at the minimum elevation angle which is not accessable to the general public. Generated 06/18/2016 Rad Haz Base file Page 2 of 2 O3b Engineering PGR


Document Created: 2016-07-12 16:39:16
Document Modified: 2016-07-12 16:39:16
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