Attachment Analysis and Calcula

This document pretains to SES-MOD-20110401-00397 for Modification on a Satellite Earth Station filing.

IBFS_SESMOD2011040100397_879462

Exhibit For Globecomm Systems, Inc. Hauppauge, New York Vertex/RSI 4.8 Meter Call Sign: E070227 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 Globecomm Systems, Inc. satellite earth station planned for Hauppauge, Suffolk, New York is in compliance with FCC REPORT & ORDER 96- 377. This analysis considers the installation of a new 4.8 meter antenna. 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): 40° 48’ 54.2” N, 73° 14’ 12.2” W • Satellite Location for Earth Station: Hispasat 1C at 30.0° W.L. • Frequency Band: 13.75-14.5 GHz for uplink • Polarizations: Linear and Circular • Emissions: 30M5G7W • Modulation: QPSK • Maximum Aggregate Uplink EIRP: 76.0 dBW for all Carriers • Transmit Antenna Characteristics Antenna Size: 4.8 meter in Diameter Antenna Type/Model: Vertex/RSI Gain: 54.9 dBi • RF power into Antenna Flange: 21.1 dBW or 6.3 dBW/ MHz or –17.7 dBW/4 kHz (Maximum) • Minimum Elevation Angle: Hauppauge, Suffolk, NY 25.6° @ 124.8° Azimuth (Hispasat-1C) • 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 and (2) Data Relay Satellites. Summary of Coordination Issues: 2) Potential Impact to Government Radiolocation (Shipboard Radar) 3) 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 Hauppauge, New York earth station is approximately 12.3 km South toward the Atlantic Ocean. The calculation of the power spectral density at this distance is given by 1. Clear Sky EIRP: 76.0 dBW 2. Carrier Bandwidth: 30.5 MHz 3. Transmit Antenna Gain: -17.7 dBW/4 kHz 4. Antenna Gain Horizon: FCC Reference Pattern 3. Antenna Elevation Angle: 52.9° The proposed earth station will radiate interference toward the ocean according to its off-axis side-lobe performance. A conservative analysis, using FCC standard reference pattern, results in off-axis antenna gains of -10.0 dBi towards the Atlantic Ocean. The calculated signal density at the shoreline, through free space is: PFD = Antenna Feed Power density (dBW/4 kHz) + Antenna Off-Axis Gain (dBi) – Spread Loss (dBw- m2). = -17.7 dBw/4 kHz + (-10.0) dBi – 10*log[4Π(12300m)2] = -120.5 dBW/m2/4 kHz + Additional Path Losses (~ 51.0 dB) = -171.5 dBW/ m2/4 kHz

Our calculations show additional path losses of approximately 51.0 dB including absorption loss and earth diffraction loss for the actual path profiles from the proposed earth station to the nearest shoreline. The calculated PFD including additional path losses to the closest shoreline location is -171.5 dBW/m2/4 kHz. This is 4.5 dB below 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 Hauppauge, New York earth station due to the distance and the terrain blockage between the site and the shore. 3. Potential Impact to NASA’s Data Relay Satellite System (TDRSS) The geographic location of the Globecomm Systems Inc. earth station in Hauppauge, New York 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 Globecomm Systems Inc. earth station in Hauppauge, New York. 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 4.8 meter earth station dish will have an EIRP less than 71 dBW/6 MHz in this band. The total EIRP for all carriers is 76.0 dBW, and the equivalent EIRP per 6 MHz segment will be 68.9 dBW/ 6 MHz. Since this EIRP is less than 71 dBW/6 MHz,. there will not be interference to the TDRSS space-to-space link for the 30.5 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 Hauppauge facility, and the US Navy and NASA systems space-to-earth and space-to-space links are likely.


Document Created: 2011-03-29 13:17:22
Document Modified: 2011-03-29 13:17:22
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