Attachment Response fr Orbimage

Response fr Orbimage

REPLY submitted by Orbimage

Response from Orbimage

2005-09-01

This document pretains to SAT-MOD-20050511-00097 for Modification on a Satellite Space Stations filing.

IBFS_SATMOD2005051100097_453883

James F. Rogers 555 Eleventh Street, N.W., Suite 1000 Direct Diak: (202) 637—2215 Washington, D.C. 200041804 jim.rogers@Iw.com Tek: (202) 637—2200 Fax: (202) 687—2201 www.lw.com LATHAM&WATKINS« Boston FIRM / AFFILIATE OFFICES New York Brussels Northem Virginia Chicago Orange County Frankfurt Paris Hamburg San Diego September 1, 2005 Hong Kong San Francisco London Shanghai Los Angeles Silicon Valley .B_Y_I{_A—N.Q Milan Singapore Moscow Tokyo New Jersey Washington, D.C. Robert G. Nelson Chief, Engineering Branch Satellite Division International Bureau Federal Communications Commission Washington, DC 20554 Re: Application of ORBIMAGE, Inc. Call Sign $2348 File No. SAT—MOD20050511—0097 Dear Mr. Nelson: In response to your letter of August 11, 2005, concerning the above application, ORBIMAGE has prepared the attached letter providing the information you requested. Please feel free to call or email me if you have any further questions. Very truly yours, %&v J [<ag 3 Jamsz’é F. Rogers ofLATHAM & WATKINS LLP Enclosure ce: Fern Jarmulnek (International Bureau) Sylvia Lam (International Bureau) Lee F. Demitry (ORBIMAGE) William Lee Warren, Esq. (ORBIMAGE) David Kenyon (ORBIMAGE)

!%RBIMAGE GLOBAL IMAGING INFORMATION August 30, 2005 Robert G. Nelson Chief Engineering Branch Satellite Division International Bureau Federal Communications Commission Washington, D.C. 20554 Re: Application of ORBIMAGE, Inc. Call Sign $2348 File No. SAT—MOD20050511—00097 Dear Mr. Nelson: ORBIMAGE, Inc. (CORBIMAGE") hereby responds to your letter dated August 10, 2005 requesting supplemental information concerning the above—referenced application to modify its existing license to add an additional satellite, OrbView—5 ("OV—5"). The letter indicated that further clarification and additional information was needed in order to facilitate the coordination between the Commission and NTIA. Accordingly, ORBIMAGE was asked to supply three items ofinformation: First, the Commission requested that ORBIMAGE provide the frequency response of the filter described in Exhibit 2, Technical Annex, page 7 of the application and to explain whether these characteristics are the same as those of the current constellation. Second, ORBIMAGE was asked to provide the maximum power spectral density ("PSD") in the frequency range of 8400 MHz—8450 MHz for the Telemetry Downlink. Finally, the letter requested that ORBIMAGE provide the crossing time of the ascending node of OV—5. In response to the first inquiry, ORBIMAGE provides the filter response in the attached Exhibit A. The OV—5 filter characteristics are not the same as those on the current constellation, OV—3. The OV—5 x—band downlink covers a wider bandwidth (370 MHz) than the OV—3 downlink (150 MHz). In addition, the OV—3 center frequency of 8190 MHz differs from the OV— 5 center frequency of 8210 MHz. In response to the second inquiry, ORBIMAGE provides the maximum PSD in the attached Exhibit B. ORBIMAGE is aware that the Commission may have a particular concern about the potential for interference with the Deep Space Network ("DSN"). Accordingly, ORBIMAGE examined the potential for interference with the DSN in the context of the ITU regulations. Because the OV—5 transmitters are deactivated, except when over a ground station, the only potential for interference is between ORBIMAGE‘s Dulles Ground station and DSN‘s Goldstone antenna. As demonstrated in the attached exhibits, ORBIMAGE calculated the worst—case DC\787587. 1

scenario for this potential interference and found that the interference potential is well within the ITU‘s recommendations. In response to the Commission‘s third inquiry, the satellite crossing time ofthe descending node is controlled to be 10:30 AM +/— 20 minutes. Thus, the ascending nodal crossing time is 10:30 PM. If you have additional questions concerning the above—referenced application, please contact the undersigned. Respectfully submitted, t William L. Warren DCUS7587.1

EXHIBIT A DSN Filter Response Figure 1 shows the OV—5 DSN filter response. Series 1 is the ideal filter response and Series 2 is the actual filter response. AMPLITUDE IDEAL VS. PROTYPE Rord 6Q Th _lgsg_q baid baed %;w h m ~10 s FREQ MHZ Figure 1. OV—5 DSN Filter Response The following calculations show that the 370 Mbps wideband downlink meets the ITU Recommendation ITU—R SA. 1157 Protection Criteria for Deep—Space Research with at least 6.85 dB of margin. Power Flux Density Calculation @ 4 kHz Integration The NTIA and ITU PFD recommendations specify a not to exceed PFD value for all ground point locations. The recommendations dictate that the PFD shall be integrated over a 4 kHz bandwidth. This can be seen in the below equation. PFD=Tx(dBW) + SCAntennaGain(dB) + Losses(dB) +10* Log( V_ , D(myp2) +!90* Log(400%w> + ModLoss (Worst Case Scenario) Simulations showed that the angle between the boresight of the antenna during a contact with the Dulles, VA ground station and the 70—meter DSN antenna at Goldstone to be > 76. Calculations where made for a worst—case PFD in which the maximum gain (of angles > 76) and closest range (when both sites are in DC\787587.1

view) are used. The maximum amount of PFD at the ground at the downlink channel centerfrequency becomes: (Assuming) Tx (dBW) 10 Watt Transmitter = 10 dBw i Tx Frequency 8210 MHz dt SCAntennaGain (dB) 3 dBi Antenna Gain nb Losses (dB) —8 dB Filter + Cable + Gimbal D{m) ar db 2027 km slant range ~ 2,027,000 m (closest approach) BW (MHz) 370 MHz iob Modulation Loss 0 dB PFD = (10 dBW) + (3dB) + (—8 dB) + (—137.13 dB/m*) + (—49.66 dB/4kHz) + (0 dB) PFD = ~181.79 dB(W/m"/4kHz) Converting the 4 kHz BW to 1 Hz BW:; 10 log (4000) = 36.02 dB PFD = (—181.79 dBW/m"/4kHz) — (36.02 dB) PFD = —217.81 dB(W/m*/Hz) The ITU Recommendation ITU—R S$A.1157 Protection Criteria for Deep—Space Research states that the maximum allowable interference power spectral flux—density into a DSN receiver is —255.1 dB(W/im*/Hz). The rejection required in the Deep—Space Research band is: Regquired Rejection = Max SC PFD — DSN specification Required Rejection = (—217.81 dB(W/m*/Hz)) — (— 255.1 dB(W/m"/Hz)) Required Rejection = 37.29 dB The spectral density of the signal = P/SR Sin@(mAf/SRY/(mTAf/SR)"; where SR is the symbol rate and Af is the delta frequency from center the frequency. Freq (Ffo/SR) 10 tog [(sin®\/x"] (dB) 8400 1.027027 —31.60 8410 1.081081 —22.59 8420 11351 18.75 8430 1189189 16.48 8440 1.243243 15.03 8450 1.297297 4410 The required filter attenuation by frequency is: Regquired filter attenuation = 37.29 dB + 10 log((sin®x}/x") in the 8400 to 8450 MHz band Regquired filter attenuation @ 8400 MHz = (37.29 dB) + (—31.60 dB) Required filter attenuation @ 8400 MHz = 5.69 dB Actual filter attenuation @ 8400 MHz = 21 dB Margin @ 8400 MHz = 15.31 dB DC\787587.1

Required filter attenuation @ 8410 MHz = (37.29 dB) + (—22.59 dB) Required filter attenuation @ 8410 MHz = 14.70 dB Actual filter attenuation @ 8410 MHz = 24 dB Margin @ 8410 MHz = 9.30 dB Required filter attenuation @ 8420 MHz = (37.29 dB) + (—18.75 dB) Required filter attenuation @ 8420 MHz = 19.15 dB Actual filter attenuation @ 8420 MHz = 26 dB Margin @ 8420 MHz = 6.85 dB Required filter attenuation @ 8430 MHz = (37.29 dB) + (—16.48 dB) Required filter attenuation @ 8430 MHz = 20.81 dB Actual filter attenuation @ 8430 MHz = 28 dB Margin @ 8430 MHz =7.19 dB Required filter attenuation @ 8440 MHz = (37.29 dB) + (—15.03 dB) Required filter attenuation @ 8440 MHz = 22.26 dB Actual filter attenuation @ 8440 MHz = 31 dB Margin @ 8440 MHz = 8.74 dB Required filter attenuation @ 8450 MHz = (37.29 dB) + (—14.10 dB) Required filter attenuation @ 8450 MHz = 23.19 dB Actual filter attenuation @ 8450 MHz = 33 dB Margin @ 8450 MHz = 9.81 dB DC\787387.1

EXHIBIT B Power Spectral Density in the frequency range of 8400 to 8450 MHz for the telemetry downlink The PSD of the telemetry downlink is at the most —70 dBc in the 8400 to 8450 MHz range. This is due to spurious emissions rather than modulated data. The following calculations show that the telemetry downlink meets the ITU Recommendation ITU—R SA. 1157 Protection Criteria for Deep—Space Research with 8.09 dB of margin. Power Flux Density Calculation @ 4 kHz Integration The ITU PFD recommendations specify a not to exceed PFD value for all ground point locations. The recommendations dictate that the PFD shall be integrated over a 4 kHz bandwidth. This can be seen in the below equation: PFD=Tx(dBW) + SCAntennaGain{dB) + Losses(dB)+10* Log( ;, , Dimp2) +19* Lng(400%w) + ModLoss Simulations showed that the closest slant range to the 70 Meter antenna at Goldstone (when both Goldstone and the Dulles ground site are in view) is 2027 km. This is the only time that the TLM Transmitter can be on. The maximum amount of PFD at the ground at the downlink channel center frequency becomes: (Assuming) Tx 2 Watt Transmitter = 3 dBW ut Tx Frequency 8394 MHz di SC Antenna Gain 0 dBi Maximum Antenna Gain at 8400 MHz db Losses ~11 dB (Attenuator + Cable + Coupler) db D 2027 km slant range ~ 2,027,000 m (closest approach) ar BW 64 kHz W Modulation Loss 0 dB PFD = (3 dBW) + (0dB) + (—11 dB) + (—137.13 dB/m") + (—12.04 dB/4kHz) + (0 dB) PFD = —157.17 dB(W/m*/4kHz) The TLM signal is —70 dBc at 8400 to 8450 MHz. This is the spurious behavior of the transmitter; the data PSD at this distance from the center frequency is lower. PSD at 8400 MHz = PFD + TLM PSD at 8400 MHz PFD at 8400 MHz = (—157.17 dBW/m*/4kHz) + (—70 dB) PFD at 8400 MHz = —227.17 dB(W/m"/4kHz) The ITU Recommendation ITU—R SA. 1157 Protection Criteria for Deep—Space Research states that the maximum allowable interference power spectral flux—density into a DSN receiver is —255.1 dB(W/mlez), Converting the 4 kHz BW to 1 Hz BW: 10 log (4000) = 36.02 dB PFD at 8400 MHz = (—227.17 dBW/m*/4kHz) — (36.02 dB) PFD at 8400 MHz = —263.19 dB(W/m*/Hz) Margin to ITU—R SA. 1157 = (—263.19 dB(W/im"/H2)) — (—255.1 dB(W/m"/H2z)) DC\787587.1

. Margin to ITU—R SA.1157 = 8.09 dB DC\787587.1


Document Created: 2005-09-08 09:14:25
Document Modified: 2005-09-08 09:14:25
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