ITU-R SA 1742-2006 Technical and operational characteristics of interplanetary and deep-space systems operating in the space-to-Earth direction around 283 THz《运行在283 THz周围空间-地球方向的行.pdf
《ITU-R SA 1742-2006 Technical and operational characteristics of interplanetary and deep-space systems operating in the space-to-Earth direction around 283 THz《运行在283 THz周围空间-地球方向的行.pdf》由会员分享,可在线阅读,更多相关《ITU-R SA 1742-2006 Technical and operational characteristics of interplanetary and deep-space systems operating in the space-to-Earth direction around 283 THz《运行在283 THz周围空间-地球方向的行.pdf(18页珍藏版)》请在麦多课文档分享上搜索。
1、 Rec. ITU-R SA.1742 1 RECOMMENDATION ITU-R SA.1742 Technical and operational characteristics of interplanetary and deep-space systems operating in the space-to-Earth direction around 283 THz (Question ITU-R 235/7) (2006) Scope This Recommendation specifies technical parameters (frequencies, link, si
2、gnal and data characteristics, antenna parameters, etc.) and operational characteristics of interplanetary and deep-space systems operating in the space-to-Earth direction around 283 THz, which could be used in sharing studies. The ITU Radiocommunication Assembly, considering a) that telecommunicati
3、on links are being planned for use on some satellite systems for deep-space and interplanetary radiocommunications at frequencies in the region of 283 THz; b) that, using recent technological developments, astronomers are making a concerted effort to build telescopes and make observation in this seg
4、ment of the spectrum; c) that this segment of the spectrum is also being used for other terrestrial and space services; d) that this segment of the spectrum is also being used for scientific and industrial purposes other than radiocommunication; e) that mechanisms of interference between satellites
5、operating in deep-space and passive systems such as astronomy operating above 20 THz may differ from those in the radio-frequency portion of the spectrum, recognizing 1 that No. 78 of Article 12 of the ITU Constitution states a function of the Radiocommunication Sector includes, “. carrying out stud
6、ies without limit of frequency range and adopting Recommendations .”; 2 that, under Note 2 of No. 1005 in the Annex to the ITU Convention, Study Groups may consider “radiocommunication” to include electromagnetic spectrum above 3 000 GHz propagated through space without artificial guide in the cours
7、e of their studies and in the creation of draft new Recommendations; 3 that use and sharing of this segment of the spectrum has not been thoroughly studied within the ITU-R, recommends 1 that sharing studies considering space research satellites operating in the space-to-Earth direction around 283 T
8、Hz in deep space should take into account the technical and operational parameters presented in Annexes 1 and 2. 2 Rec. ITU-R SA.1742 Annex 1 1 Introduction The increased pressure for use of the radio spectrum and the advancement of technology, there is more attention being given to the use of frequ
9、encies above 3 000 GHz for free space radiocommunications. Radiocommunication links have become a reality in the frequency bands above 3 000 GHz as a result of many recent technological developments in the field of optical fibre telecommunication especially in the area of lasers, modulation and rece
10、iver technology. Free space radiocommunication at frequencies above 3 000 GHz has the ability to support higher data rates with less mass than traditional radio-frequency systems as well as meet gain and directivity requirements of beams used for deep-space applications. 1.1 Frequency considerations
11、 Currently, most of the interest in free space radiocommunication links above 3 000 GHz is focused around the frequencies 200, 283, 311 and 353 THz1, whose corresponding wavelengths are approximately 1.5, 1.06, 0.965 and 0.850 m. These frequencies are the same as those most widely used for telecommu
12、nications in optical fibres. For interplanetary and deep-space radiocommunication in the space-to-Earth direction, attention is being focused on use of Ytterbium-doped (Yb) fibre-optical amplifier at 1.06 m in a Master-Oscillator-Power Amplifier (MOPA) configuration, Q-switched, Neodymium: Yttrium A
13、luminium Garnet (Nd:YAG) or Neodymium: Yttrium Vanadate (Nd:YVO4) lasers operating around 283 THz (1.06 m) though, depending on mission requirements, other frequencies are feasible. The use of Yb, Nd:YAG and Nd:YVO4are of primary use due to availability and reliability. 1.2 Generic mission parameter
14、s Technical parameters suitable for interference analyses should be based on generic interplanetary missions to Mars and Jupiter. For the purposes of minimizing weight and power consumption, the links must support radiocommunication requirements beginning shortly after launch and continuing througho
15、ut the duration of the mission negating the need for additional radiocommunication systems. Therefore, link distances will vary from a few thousand km to several Astronomical Units (AU2). Distances from the Earth to Mars or Jupiter vary from 0.5 to 6.2 AU. A summary of the fundamental technical para
16、meters of a 283 THz deep-space link operating in the space-to-Earth direction is provided in Table 1. 2 Link considerations Deep-space links operating at 283 THz in the space-to-Earth direction may utilize Yb, Nd:YAG or Nd:YVO4lasers. The beam would be transmitted from a 30 cm telescope on board the
17、 spacecraft and received by a telescope on the Earth with an effective diameter of 4.2 m to 10 m.311 THz = 1 000 GHz. 21 AU 149 597 870 km. 3For the purposes of telecommunication through free space at around 283 THz, a telescope is effectively an antenna. Rec. ITU-R SA.1742 3 TABLE 1 Technical param
18、eters of two reference deep-space missions operating at 283 THz in the space-to-Earth direction Parameter Mars Jupiter Transmitter power 5 W (average) Transmitter aperture 30 cm Transmitter frequency (wavelength) 283 THz (1.06 m) Modulation Pulse position modulation (PPM) (M = 64 to 256) with concat
19、enated coding Pointing accuracy 0.35 rad Range 0.5 to 2.5 AU 4.2 to 6.2 AU Data rate (during the day at Earth terminal)(1)3 to 30 Mbit/s (4.2 m Earth terminal) 1.5 to 3 Mbit/s (10 m terminal) Receiver aperture 4.2 to 10 m equivalent size Detector type An array of Geiger-mode InGaAsP/InP APDs Require
20、d link margin 2 to 3 dB (1)Night-time data rates on Earth are about 30% (1.13 dB) higher. 2.1 Link performance Like a deep-space system operating in the traditional radio-frequency spectrum, performance of a link operating at 283 THz is measured in terms of data rate and bit error rate (BER). Perfor
21、mance is calculated as a function of power, telescope quality, propagation considerations, noise and receiver sensitivity. Each of these parameters is function of additional variables. 2.1.1 Data rate Unlike a deep-space system operating in the traditional radio-frequency spectrum, when all other pa
22、rameters are held constant, the data rate is not exactly inversely proportional to the square of the propagation distance; however, it is a very close approximation for links operating from the vicinity of Mars and Jupiter and thus a good rule of thumb. Data rates from Mars will vary depending on ma
23、ny parameters including link range and geometry with the sun. Data rates from Mars will generally be around an order of magnitude higher than from Jupiter. 2.1.2 BER Frames of data must have a BER of less than 106after error correction in order to be retained. A link must retain 99% of data frames.
24、2.1.3 Margin requirement The typical margin requirement of a deep-space or interplanetary link operating at 283 THz in the space-to-Earth direction is on the order of 2 to 3 dB. Conditions are dependent on factors which include inter alia weather, time of day and elevation angle. 4 Rec. ITU-R SA.174
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ITURSA17422006TECHNICALANDOPERATIONALCHARACTERISTICSOFINTERPLANETARYANDDEEPSPACESYSTEMSOPERATINGINTHESPACETOEARTHDIRECTIONAROUND283THZ

链接地址:http://www.mydoc123.com/p-793830.html