1、QUESTION ITU-R 221-1/3Propagation by way of sporadic E and other ionization(1990-2009)The ITU Radiocommunication Assembly,consideringa) that the available information on terrestrial propagation by sporadic E and other ionizationis insufficient to provide statistical data of the type needed by teleco
2、mmunication engineers,especially at low and high latitudes;b) that ionospheric irregularities including meteor ionization in the E region and the F regioncan affect the performance of radio systems;c) that suitable methods for estimating sky-wave field strength and signal dispersion arerequired by:
3、administrations, in connection with the establishment and operation of radio systems; the Radiocommunication Bureau, for further refinement of its technical standards containedwithin the Rules of Procedure; the Radiocommunication Sector, in connection with future RadiocommunicationConferences,decide
4、s that the following Questions should be studied1 What are the characteristics of sporadic-E (Es) ionization and how do these affect obliqueincidence propagation in the HF and VHF bands?2 What are the mechanisms for VHF and UHF propagation by the ionosphere and how canthe statistics of the propagation characteristics be predicted?further decides1 that the available information should be prepared as new Recommendations, or as revisionsto existing Recommendations;2 that the above studies should be completed by 2013.NOTE 1 See Recommendations ITU-R P.534 and ITU-R P.843.Category: S3
