OLSG Report_Final_06_05_12 - Interagency Operations Advisory ...

More documents

Recommendations

Info

Optical Link Study Group (OLSG) Final Report IOAG.T.OLSG.2012.V1 interference. The optical communications transmissions would become a part of this coordination process. The downlinks from the spacecraft will also have to be considered since a “bright” downlink aimed at an astronomical site that is also observing at the same wavelength could disrupt the astronomical observations. For downlinks from LEO satellites, this disruption—if it occurred—would be very brief. For downlinks from the Moon or beyond, the disruptions could be over a longer period of time, but only if the spacecraft was within the beam of the astronomical telescope—which is very narrow. Again, careful coordination would be required. Some observatory locations have decommissioned telescopes of various sizes that could be considered for use as optical communication terminals. In most cases, these telescopes range from less than 1 m up to 5 m in diameter and were designed for observing celestial bodies, so their domes and mounts would be appropriate for communication with satellites in GEO or at the Moon and beyond. Not having to build a new telescope could save money, but the trade will be that the telescopes may be in need of repair and may not be designed to operate during daytime, particularly at small Sun-Earth-Probe angles. Upgrading these existing telescopes to support LEO satellites would likely require modification to the domes and mounts. Instead of reusing complete existing telescope installations, it might also be possible to reuse only the platforms or domes, which would then be equipped with new telescopes. 5.1.1.2.3 International Space Laser Ranging (ISLR) Sites Sites that are part of the International Space Laser Ranging (ISLR) network could provide excellent locations for optical communication ground terminals (see Section 7.4 for a list of sample sites). First, these sites were selected for good propagation characteristics and have some infrastructure. Second, since the ISLR stations both transmit and receive, the ability to transmit is a given, though coordination with existing site operations will be required. These sites would be good for hosting optical communications facilities, and in some cases the existing laser ranging telescopes could be modified with appropriate transmitters and receivers for optical communications. 5.1.1.3 Future Collaborative Sites It is possible that existing sites will not provide the geographic diversity needed to optimize data return relative to the CFLOS statistics. The establishment of new sites capable of providing cross support at favorable locations with existing infrastructure is also a likely approach, as the ground station network is expanded. Several terminals might be sited at any one location to enable support for more than one mission or scenario, and provide infrastructure cost savings. Sharing of sites by multiple agencies (co-location of terminals) can provide global coverage if required. Even if agreement cannot be reached on interoperable standards, a minimum level of collaboration can be achieved through colocation of optical terminals at favorable locations. 5.2 Earth Relay Constellation Cost The cost estimate for a complete optical Earth Relay Constellation modeled after the NASA TDRS system leads to a cost of 1,651,920 k€ (refer to Section 4.1.6.2 for details) Page | 138
5.3 Standardization Considerations Optical Link Study Group (OLSG) Final Report IOAG.T.OLSG.2012.V1 Table 31 represents a set of parameters that need to be defined to ensure compatibility in a cross-support scenario using optical space communication. The parameters are split into two categories: Cross-support interface parameters describing characteristics that must be mutually communicated and agreed upon in order to ensure compatibility for cross support (i.e., the “What”). Implementation parameters describing station-internal engineering characteristics of the ground station’s technical implementation in order to satisfy/meet the interface parameters (i.e., the “How”). Conversely, an existing station’s design/implementation will determine the level of compatibility with a given interface requirement. Note that the Beacon, Transmit and Receive Telescope and Laser implementation parameters are listed separately, following their logical functions. The actual implementation could well combine some or all of the functions in a single device—or keep them as separate installations. Page | 139
Page 1 and 2:
IOAG.T.OLSG.2012.V1 Interagency Ope
Page 3 and 4:
Optical Link Study Group (OLSG) Fin
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page | 17 Optical Link Study Group
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
2.4.5 Weather and Atmospheric Monit
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
3.1.2.1 Space Terminal Potential Im
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
3.2 Highly Elliptical Earth Orbit (
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
3.5.1.2 Scenario Concept of Operati
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88: Optical Link Study Group (OLSG) Fin
Page 103 and 104: 3.7.6 Ground Station Cost Optical L
Page 137: Optical Link Study Group (OLSG) Fin
Page 141 and 142: Functional breakdown Cross support
Page 155 and 156: 7.3 Astronomical Site Survey Optica
Page 161 and 162: Appendix A. List of Acronyms 2-PSK
show all

OLSG Report_Final_06_05_12 - Interagency Operations Advisory ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?