1. 15 May 2006ICTP, Space Weather - METU-NN1 ICTP-COST-USNSWP-CAWSES-INAF-INFN International Advanced School on Space Weather 2-19 May 2006, Trieste, Italy FORECASTING TOTAL ELECTRON CONTENT (TEC) FOR CONSTRUCTING MAPS ESPECIALLY DURING HIGH SOLAR ACTIVITY PERIODS Erdem Turker Senalp(1), Ersin Tulunay(1), Sandro Maria Radicella(2), Yurdanur Tulunay(3) (1)Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey, senalp@metu.edu.tr, ersintul@metu.edu.tr (2)Aeronomy and Radiopropagation Laboratory, Abdus Salam International Centre for Theoretical Physics, Trieste, Italy, rsandro@ictp.trieste.it (3)Department of Aerospace Engineering, Middle East Technical University, Ankara, Turkey, ytulunay@metu.edu.tr

2. 15 May 2006ICTP, Space Weather - METU-NN2 Contents - Biological to Artificial Neurons - Middle East Technical University Neural Network model (METU NN) - METU NN Forecasting TEC Maps - Results - Conclusions - References

3. 15 May 2006ICTP, Space Weather - METU-NN3 Biological to Artificial Neurons Tulunay, 2004 Halici, 2006 METU-NN

4. 15 May 2006ICTP, Space Weather - METU-NN4 Middle East Technical University Neural Network model (METU NN) METU NN Forecasting TEC Maps [1] - power of forecasting non-linear process parameters -forecast TEC values and the maps [1] -Observed GPS TEC data [Ciraolo, 2004] : - Ten minute vertical TEC data between 1 Nov. 2003 and 11 Dec. 2003 - 104 grid locations centered over Italy between latitudes of (35.5º N; 47.5º N) and longitudes of (5.5º E; 19.5º E) [1] Tulunay E., Senalp E.T., Radicella S.M., Tulunay Y., Forecasting TEC Maps by Neural Network Technique, Radio Science, submitted in 2005, (2006).

5. 15 May 2006ICTP, Space Weather - METU-NN5 METU NN technique - to forecast TEC grid values - surfaces in mapping the forecast grid values

6. 15 May 2006ICTP, Space Weather - METU-NN6 -Figure 1. Observed (dotted) and 1 hour ahead forecast (solid) TEC during 16 Nov. 2003 03:10 UT - 29 Nov. 2003 24:00 UT for single grid point (13.5˚ E; 41.5˚ N) Results

7. 15 May 2006ICTP, Space Weather - METU-NN7 - Figure 2. Scatter Diagram (dots) with best-fit line (solid) for the 1 hour ahead Forecast mapping and Observed TEC values for single grid point (13.5˚ E; 41.5˚ N) for 20 November 2003

8. 15 May 2006ICTP, Space Weather - METU-NN8 METU NN technique - to forecast TEC grid values - surfaces in mapping the forecast grid values

9. 15 May 2006ICTP, Space Weather - METU-NN9 -Video 1. Observed and 1 hour ahead forecast TEC Maps by METU-NN during the afternoon of 20 Nov. 2003

10. 15 May 2006ICTP, Space Weather - METU-NN10 - Figure 3. Absolute Error Map of observed and 1 hour ahead forecast TEC during 16-29 Nov. 2003

11. 15 May 2006ICTP, Space Weather - METU-NN11 Location 11.5˚E 38.5˚N 13.5˚E 41.5˚N 15.5˚E 44.5˚N Overall TEC Map Root Mean Square Error (TECU) 2.15562.05012.14442.2969 Absolute Error (TECU) 1.57851.48461.51681.6537 Normalized Error 0.14290.15220.16300.1563 Cross Correlation Coefficient 0.97750.97460.96960.9699 Table 1. Error Table for 1 h in advance forecasts by METU-NN for the validation time period (16-29 Nov. 2003) The forecast mapping error values - within operational tolerance [Radicella, 2004].

12. 15 May 2006ICTP, Space Weather - METU-NN12 Conclusions -The system reached correct operating point during training -METUNN learned the inherent nonlinearities of the process -Representable data in inputs + Proper construction of METUNN = complex nonlinear processes are modelled

13. 15 May 2006ICTP, Space Weather - METU-NN13 References Tulunay E., Senalp E.T., Radicella S.M., Tulunay Y. (2006), Forecasting TEC Maps by Neural Network Technique, Radio Science, (submitted in 2005). Ciraolo, G. (2004), Private communication. Radicella S.M. (2004), Private communication. Tulunay, E. (1991), Introduction to Neural Networks and their Application to Process Control, in Neural Networks Advances and Applications, edited by E. Gelenbe, 241-273, Elsevier Science Publishers B.V., North-Holland. Tulunay E., E.T. Senalp, Lj.R. Cander, Y.K. Tulunay, A.H. Bilge, E. Mizrahi, S.S. Kouris, N. Jakowski (2004), Development of algorithms and software for forecasting, nowcasting and variability of TEC, Annals of Geophysics, 47(2/3), 1201-1214. Tulunay Y., E. Tulunay, and E.T. Senalp (2001), An Attempt to Model the Influence of the Trough on HF Communication by Using Neural Network, Radio Science, 36(5), 1027-1041, September - October 2001. Tulunay Y., E. Tulunay, and E.T. Senalp (2004-a), The Neural Network Technique-1: A General Exposition, Adv. Space Res., 33(6), 983-987. Tulunay Y., E. Tulunay, and E.T. Senalp (2004-b), The Neural Network Technique-2: An Ionospheric Example Illustrating its Application, Adv. Space Res., 33(6), 988-992. Halici, U. (2006), Artificial Neural Networks, Lecture Notes, Ch1, METU EEE, Ankara, Turkey, 3, 8. “http://vision1.eee.metu.edu.tr/%7Ehalici/543LectureNotes/lecturenotes-pdf/ch1.pdf”.