Data Driven Models in Relation to Telecommunication and Navigation Systems 
 
Yurdanur Tulunay1, Ersin Tulunay2 
 
[1] METU/ODTÜ Dept. of Aerospace Engineering, 06531, Ankara, Turkey 
[2] METU/ODTÜ Dept. of Electrical and Electronics Engineering, 06531, Ankara, 
Turkey 
 
Since 1990 there have been five EU activities under the acronym of COST 
(Cooperation in the Field of Scientific and Technical Research) focused on 
understanding the ionosphere, space weather and its impact on communication and 
navigation.  These actions are COST238, COST251, COST271, COST724 and the 
ongoing action of COST296.  In particular, within the context of COST271 and 
COST296, the mitigation techniques are interpreted as means of reducing 
propagation impairments to radio systems [Y. Tulunay & Bradley 2004, Annals of 
Geophysics, supplement to Vol. 47, M.2/3, 2004.] 
 
During the COST actions, direct ionospheric parameters, i.e. the regularly 
monitored space weather parameters are used to generate corresponding to the 
same epoch and forecast ionospheric maps and models and the associated 
propogation models towards the implementation of the most appropriate mitigation 
techniques. 
 
During the COST251, 271, 296 and 724 Actions, it has been demonstrated by the 
authors and others that, the data driven models are very promising to be used in 
parallel with the mathematical methods based on first physical principles.  Data 
driven models are not only used for forecast, nowcast and retrospective 
reconstruction but they could be also employed to fill in the data gaps and help 
to construct the mitigation scenarios in advance.