Attachment Frequency Coordinati SES-AMD-20160121-00092

Attachment Frequency Coordinati

This document pretains to SES-AMD-20160121-00092 for Amended Filing on a Satellite Earth Station filing.

IBFS_SESAMD2016012100092_1123750

Exhibit For
The Christian Broadcasting Network, Inc
Virginia Beach, Virginia
(Call Sign: E970050)
Radiation Systems / 551KS 5.5 Meter Earth Station

Compliance with FCC Report & Order (FCC96-377) for the 13.75 - 14.0 GHz Band
Analysis and Calculations

1. Background

This Exhibit is presented to demonstrate the extent to which the licensed The Christian
Broadcasting Network, Inc. satellite earth station (E970050), which is being modified in Virginia
Beach, Virginia, is in compliance with FCC REPORT & ORDER 96-377. The potential
interference from the earth station to US Navy shipboard radiolocation operations (RADAR) and
the NASA space research activities in the 13.75 - 14.0 GHz Band is addressed in this exhibit.
The parameters for the earth station are:

Table 1. Earth Station Characteristics

• Coordinates (NAD83): 36° 48’ 1.5” N, 76° 11’ 30.0” W

• Satellite Location for Earth Station: 15° W
Telstar-12

• Frequency Band: 13.75-14.0 GHz for uplink

• Polarizations: Linear and Circular

• Emissions: 3M65G7W

• Modulation: Digital

• Maximum Aggregate Uplink EIRP: 68 dBW for the 3.65 MHz Carriers

• Transmit Antenna Characteristics
Antenna Size: 5.5 meters in Diameter
Antenna Type/Model: Radiation Systems
Gain: 56.2 dBi

• RF power into Antenna Flange: 3.65 MHz
11.8 dBW,
or -17.8 dBW/4 kHz (Maximum)

• Minimum Elevation Angles:
Virginia Beach, Va. 14.3° @ 108.2° Az. (Telstar-12) at 15° W

• Side Lobe Antenna Gain: 32 - 25*log(θ)

Because the above uplink spectrum is shared with the Federal Government, coordination in this
band requires resolution data pertaining to potential interference between the earth station and
both Navy Department and NASA systems. Potential interference from the earth station could
impact with the Navy and/or NASA systems in two areas. These areas are noted in FCC Report
and Order 96-377 dated September 1996, and consist of (1) Radiolocation and radio navigation,
(2) Data Relay Satellites.

Summary of Coordination Issues:

1) Potential Impact to Government Radiolocation (Shipboard Radar)
2) Potential Impact to NASA Data Relay Satellite Systems (TDRSS)

2. Potential Impact to Government Radiolocation (Shipboard Radar)

Radiolocation operations (RADAR) may occur anywhere in the 13.4 - 14 GHz frequency band
aboard ocean going United States Navy ships. The Federal Communication Commission (FCC)
order 96-377 allocates the top 250 MHz of this 600 MHz band to the Fixed Satellite Service
(FSS) on a co-primary basis with the radiolocation operations and provides for an interference
protection level of -167 dBW/m2/4 kHz.

The closest distance to the shoreline from the Virginia Beach, Virginia earth station is
approximately 20.6 km East toward the Virginia Beach Oceanfront. The calculation of the
power spectral density at this distance is given by:

3.65 MHz

1. Clear Sky EIRP: 68.0 dBW
2. Carrier Bandwidth: 3.65 MHz
3. PD at antenna input: -17.8
dBW/4 kHz
4. Transmit Antenna Gain: 56.2 dBi
5. Antenna Gain Horizon: FCC Reference Pattern
6. Antenna Elevation Angle : 14.3°

The earth station will radiate interference toward the Virginia Beach, Virginia Coastline
according to its off-axis side-lobe performance. A conservative analysis, using FCC standard
reference pattern, results in off-axis antenna gains of -2.05 dBi toward the Coastline.

$The signal density at the shoreline, through free space is: 3.65 MHz Carriers PFD = Antenna Feed Power density (dBW/4 kHz) + Antenna Off-Axis Gain (dBi) – Spread Loss (dBw-m2). = -17.8 dBw/4 kHz + (-2.05) dBi – 10*log[4Π*(20600m)2] = -117.1 dBW/m2/4 kHz + Additional Path Losses (~32.6 dB) = -149.7 dBW/m2/4 kHz Our calculations show additional path loss of approximately 32.6 dB including absorption loss and earth diffraction loss for the actual path profiles from the proposed earth station to the nearest shoreline. Please note these losses include close-in local buildings in the direction of the shoreline. The calculated PFD including additional path losses to the closest shoreline location is –149.7 dBW/m2/4 kHz for the 3.65 MHz carriers. This is 17.3 dB above the –167 dBW/m2/4 kHz interference criteria of R&O 96-377. In an effort to analyze the effects of earth station transmissions on naval radar systems, power flux densities were calculated from the earth station to the shipboard radars in increments from 12.8 miles to 60 miles (See Table 2). The calculation of interference level to the RADAR sidelobes was made at the initial distance of 12.8 miles. A distance of 12.8 miles (20.6 Km.) was used as the initial increment because it is the distance from the earth station site to the shoreline. This is the worst case condition. If the interference level is below the criteria at this range, it will be below the criteria at all of the greater ranges. A power flux density was also calculated from the shipboard radars to the shoreline and the reflection of the radar transmissions back to the radar. Since this flux density concerns the transmission from the ship to shore and back to the ship the mileage number is doubled. The power flux densities are based on the following formulas: Earth Station to Naval Radars PFD = PESGES / 4π r² Where: PFD = Power Flux Density PES = Power of Earth Station (-17.8 dbW/4 kHz) GES = Worst Case Earth Station Gain Toward the Shipboard Radars (-2.05 dB) 4π = 10Log(4π) = -11.0 r = Distance from ES to radars in Meters [Used 20Log(r)]$

Naval Radars to Shore and Reflection back to the Radar Source

PFD = PTGT / 4π (2r)² * (0.01 m²)

Where: PFD = Power Flux Density
PT = Power of Radar (Used 56.0 dBW for 3.65 MHz)
GT = Gain of Radar (Used 44 dB)
4π = 10Log(4π) = -11.0
2r = Distance to Shoreline and Reflection back to Radar Source
0.01m² = Size of the Radar Sectional Area of Target

Based upon calculations from the above formulas, it was determined that reflections of the radar
transmissions from the shoreline and back to the radar were 86.5 dB higher than the earth station
transmissions into the radar.

These calculations are presented in the tables below. This being the case, it can be concluded that
in the main beam, earth station operations should not be a problem for naval radar operations.

Table 2

Flux Density
Distance from Interference Desired Radar Return Radar Signal
ES to Radar From ES from (0.01m)² Target ES Interference
(Miles) (dBW/4 kHz/m²) (dBW/4 kHz/m²) (dB)

12.8 -149.7 -63.2 86.5
15.0 -150.4 -63.9 86.5
20.0 -153.9 -67.4 86.5
30.0 -157.2 -70.7 86.5
40.0 -159.6 -73.1 86.5
50.0 -161.6 -75.1 86.5
60.0 -163.2 -76.7 86.5

The calculated PFD for the 3.65 MHz emissions, which include 32.6 dB of additional path losses
to the shoreline location is –149.7 dBW/m2/4 kHz. If off axis, side lobe considerations are made,
44 dB was used as the gain of the radar and -10.0 dBi was the radar antenna side lobe gain
toward the direction of the earth station. This additional -54.0 dB will create an equivalent PFD
of -203.7 dBW/m2/4 kHz, which is 36.7 dB lower than the –167 dBW/m²/4 kHz interference
criteria of R&O 96-377.

Therefore, there should be no interference to the US Navy RADAR from the Virginia Beach
earth station in both the main beam and side lobe of the radar.

3. Potential Impact to NASA’s Data Relay Satellite System (TDRSS)

The geographic location of the The Christian Broadcasting Network, Inc. earth station in
Virginia Beach, Virginia is outside the 390 km radius coordination contour surrounding
NASA’s White Sands, New Mexico ground station complex. Therefore, the TDRSS space-to-
earth link will not be impacted by the The Christian Broadcasting Network, Inc. earth station in
Virginia Beach, Virginia.

The TDRSS space-to-space link in the 13.772 to 13.778 GHz band is assumed to be protected if
an earth station produces an EIRP less than 71 dBW/6 MHz in this band. The 5.5 meter earth
station antenna will have an EIRP less than 71 dBW/6 MHz for the 3.65 MHz carriers in this
band. The EIRP for the 3.65 MHz carriers is 68.0 dBW. The equivalent EIRP per 6 MHz
segment will be 60.2 dBW/6 MHz. Therefore, there should not be interference to the TDRSS
space-to-space link for the 3.65 MHz carriers.

4. Coordination Issue Result Summary and Conclusions

The results of the analysis and calculations performed in this exhibit indicate that compatible
operations between the earth station at the Virginia Beach facility and the US Navy and NASA
systems space-to-earth link and NASA systems space-to-space link (13772.0 to 13778.0 MHz)
will be permitted for the 1 MHz through 36 MHz carriers.

Document Created: 2016-01-21 15:38:13
Document Modified: 2016-01-21 15:38:13