دراسة اسباب فشل حدوث اتصالنقطي للموجاتعاليةالتردد HF بين بغداد وأماكنأخرىفيالعراق للأعوام 1994و1995

Abstract

In using FIF band point to point communication atBaghdad, there is a yearly report for estimated critical frequencieswhich can be forecasted at daytime and nighttime based on Tindexmethod. In this work hours of high solar and geomagneticactivity have examined to influence the wave returning point fromF region and the failure of radio connections, also the effect ofsporadic E region occulrence due these hours of disconnections,beside the problems in receiving instruments and manmade errors.Results shown that the ratio of high solar activity hours was 9.2o/oor the whole hours of disconnections and high geomagneticactivity hours ratio made I l.lYo of the total hours, while theoccurrence of Es- layer can be 30.5% of the total hours and theratio of bad use of the frequency report and failure in instrumentscan be 15.5% of the total hours of disconnection hourly cases. Theremaining 33J% is due to the reported extra hours after the liftingof the affect which may need for longer time to be haling.