ITU-R QUESTION 88-14-1990 Propagation and mobile earth station antenna characteristics for mobile-satellite services《移动卫星业务的传输和移动地球站天线特性》.pdf

《ITU-R QUESTION 88-14-1990 Propagation and mobile earth station antenna characteristics for mobile-satellite services《移动卫星业务的传输和移动地球站天线特性》.pdf》由会员分享，可在线阅读，更多相关《ITU-R QUESTION 88-14-1990 Propagation and mobile earth station antenna characteristics for mobile-satellite services《移动卫星业务的传输和移动地球站天线特性》.pdf（1页珍藏版）》请在麦多课文档分享上搜索。

1、QUESTION ITU-R 88-1/4*Propagation and mobile earth station antenna characteristics for mobile-satellite services (1988-1990) The ITU Radiocommunication Assembly, considering a) that mobile earth-station antenna performance substantially affects system design in mobile-satellite services; b) that mul

2、tipath fading due to reflection and shadowing due to foliage and natural or man-made structures are important factors in designing and constructing mobile-satellite systems; c) that there are various techniques which may be adopted for keeping mobile earth station antennas pointed correctly; d) that

3、 the configuration of airborne antenna systems is severely constrained by the effect on aircraft performance; e) that services using medium and low gain antennas are being used by systems of the International Mobile Satellite Organization (IMSO) and other organizations; f) that characteristics of mu

4、ltipath fading are being studied in ITU-R Study Group 3 under Question ITU-R 207/3; g) that some mobile ship, aircraft and land earth stations will be operating at high latitudes of the globe and may consequently have special propagation and antenna design problems, decides that the following Questi

5、on should be studied 1 What are the preferred types of antenna systems and their characteristics for: 1.1 shipborne use; 1.2 airborne use; 1.3 land use; taking into account that some mobile earth stations may have elevation angles of less than 5 to satellites in the geostationary orbit? 2 What fading reduction techniques can be applied to mobile antenna systems in a mobile-satellite service? _ *Former Question ITU-R 88-1/8.