1、QUESTION ITU-R 129-2/7*, *Unwanted*emissions radiated from and received by stations of the science services*(1990-1993-2003) The ITU Radiocommunication Assembly, considering a) that the radiation of unwanted emissions by space stations or earth stations of the science services could cause interferen
2、ce to other services; b) that the radiation of unwanted emissions by other services could cause interference to space stations and earth stations of the science services; c) that the various radio services differ greatly in the sensitivity of their stations to interference; d) that the specification
3、 of acceptable levels of unwanted emissions must take into account the practical aspects of achieving these levels; e) that limitations on the level of unwanted emissions should take into account the probability of simultaneous interference to a station from more than one interfering source; f) that
4、 there is a need to adopt a standard technique for the measurement of unwanted emissions in order to determine compliance with specified levels of these emissions, noting a) that Appendix 3 of the Radio Regulations specifies only the maximum permitted levels of spurious emissions for transmitters of
5、 stations of the space services; b) that Recommendation 66 (Rev.WRC-2000) recommends the ITU-R study the question of unwanted emissions resulting from transmitters of all services and all modulation methods, and on this basis to develop recommendations for maximum permitted levels of unwanted emissi
6、ons, _ *In the year 2009, Radiocommunication Study Group 7 extended the completion date of studies for this Question. *This Question should be brought to the attention of Radiocommunication Study Groups 1, 4, 6, 8 and 9. *Unwanted emissions include both spurious and out-of-band emissions. *Science s
7、ervices include space operation, space research, Earth exploration-satellite, meteorological-satellite and standard frequencies and time signals services, radio astronomy and radar astronomy. - 2 - decides that the following Question should be studied 1 What limits, based upon practical consideratio
8、ns, should be placed upon the power of unwanted emissions radiated by space and earth stations of the science services in order to protect other services? 2 What levels of unwanted emissions from stations of other services are acceptable at space and earth stations of the science services? 3 In what
9、 ways can radio astronomy and passive sensor observations be affected by unwanted emissions from radio transmitters, and from other electrical equipment? 4 What techniques may be employed at space and earth stations of the science services to mitigate the effects of unwanted emissions? further decides 1 that the results of the above studies should be included in (a) Recommendation(s); 2 that the above studies should be completed by 2011.
