ANGEO Annales Geophysicae ANGEO 1432-0576 Copernicus GmbH Göttingen, Germany 10.5194/angeo-30-797-2012 A new global model for the ionospheric F2 peak height for radio wave propagation Hoque M. M. 1 Jakowski N. 1 Institute of Communications and Navigation, German Aerospace Center, Neustrelitz, Germany 07 05 2012 30 5 797 809 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.ann-geophys.net/30/797/2012/angeo-30-797-2012.html The full text article is available as a PDF file from http://www.ann-geophys.net/30/797/2012/angeo-30-797-2012.pdf

The F2-layer peak density height <I>hm</I>F2 is one of the most important ionospheric parameters characterizing HF propagation conditions. Therefore, the ability to model and predict the spatial and temporal variations of the peak electron density height is of great use for both ionospheric research and radio frequency planning and operation. For global <I>hm</I>F2 modelling we present a nonlinear model approach with 13 model coefficients and a few empirically fixed parameters. The model approach describes the temporal and spatial dependencies of <I>hm</I>F2 on global scale. For determining the 13 model coefficients, we apply this model approach to a large quantity of global <I>hm</I>F2 observational data obtained from GNSS radio occultation measurements onboard CHAMP, GRACE and COSMIC satellites and data from 69 worldwide ionosonde stations. We have found that the model fits to these input data with the same root mean squared (RMS) and standard deviations of 10%. In comparison with the electron density NeQuick model, the proposed Neustrelitz global <I>hm</I>F2 model (Neustrelitz Peak Height Model – NPHM) shows percentage RMS deviations of about 13% and 12% from the observational data during high and low solar activity conditions, respectively, whereas the corresponding deviations for the NeQuick model are found 18% and 16%, respectively.

 References Altinay, O., Tulunay, E., and Tulunay, Y.: Forecasting of ionospheric critical frequency using neural networks, Geophys, Res. Lett., 24, 1467–1470, 1997. Angling, M. J.: First assimilations of COSMIC radio occultation data into the Electron Density Assimilative Model (EDAM), Ann. Geophys., 26, 353–359, http://dx.doi.org/10.5194/angeo-26-353-2008doi:10.5194/angeo-26-353-2008, 2008. Bilitza, D.: International reference ionosphere 2000, Radio Sci., 36, 261–275, http://dx.doi.org/10.1029/2000RS002432doi:10.1029/2000RS002432, 2001. Bilitza, D. and Reinisch, B. W.: International Reference Ionosphere 2007: Improvements and new parameters, Adv. Space Res., 42, 599–609, http://dx.doi.org/10.1016/j.asr.2007.07.048doi:10.1016/j.asr.2007.07.048, 2008. Bilitza, D., Sheikh, N. M., and Eyfrig, R.: A global model for the height of the F2-peak using M3000 values from CCIR, Telecommun. J., 46, 549–553, 1979. Bilitza, D., Rawer, K., Bossy, L., Kutiev, I., Oyama, K., Leitinger, R., and Kazimirovsky, E.: International Reference ionosphere 1990, Nat. Space Sci. Data Cent., Report 90-22, Greenbelt, Md, 1990. Bradley, P. A. and Dudeney, J. R.: A simple model of the vertical distribution of electron concentration in the ionosphere, J. Atmos. Terr. Phys., 35, 2131–2146, 1973. CCIR: Atlas of ionospheric characteristics, Comite' Consultatif International des Radiocommunications, Reports, 340, 340-2, later supllements, ITU, Geneva, 1967. Coisson, P., Radicella, S. M., Leitinger, R., and Nava, B.: Topside electron density in IRI and NeQuick: Features and limitations, Adv. Space Res., 37, 937–942, 2006. Dudeney, J. R.: An improved model of the variation of electron concentration with height in the ionosphere, J. Atmos. Terr. Phys., 40, 195–203, 1978. Dudeney, J. R.: The accuracy of simple methods for determining the height of the maximum electron concentration of the F2-layer from scaled ionospheric characteristics, J. Atmos. Terr. Phys., 45, 629–640, http://dx.doi.org/10.1016/S0021-9169(83)80080-4doi:10.1016/S0021-9169(83)80080-4, 1983. Fox, M. W. and McNamara, L. F.: Improved world-wide maps of monthly median of \emphfoF2, J. Atmos. Terr. Phys., 50, 1077–1086, 1988. Gulyaeva, T. L., Bradley, P. A., Stanislawska, I., and Juchnikowski, G.: Towards a new reference model of \emphhmF2 for IRI, Adv. Space Res., 42, 666–672, http://dx.doi.org/10.1016/j.asr.2008.02.021doi:10.1016/j.asr.2008.02.021, 2008. Hajj, G. A. and Romans, L. J.: Ionospheric electron density profiles obtained with the Global Positioning System: Results from the GPS/MET experiment, Radio Sci., 33, 175–190, 1998. Hoque, M. M. and Jakowski, N.: Estimate of higher order ionospheric errors in GNSS positioning, Radio Sci., 43, RS5008, http://dx.doi.org/10.1029/2007RS003817doi:10.1029/2007RS003817, 2008. Hoque, M. M. and Jakowski, N.: Ionospheric bending correction for GNSS radio occultation signals, Radio Sci., 46, RS0D06, http://dx.doi.org/10.1029/2010RS004583doi:10.1029/2010RS004583, 2011a. Hoque, M. M. and Jakowski, N.: A new global empirical \emphNmF2 model for operational use in radio systems, Radio Sci., 46, RS6015, http://dx.doi.org/10.1029/2011RS004807doi:10.1029/2011RS004807, 2011b. ITU-R: Reference ionosphere characteristics, Recommendation, P.1239 (approved in 1997-05, managed by ITU-R Study Group SG3), 1997. Jakowski, N., Wehrenpfennig, A., Heise, S., Reigber, C., and Lühr, H.: GPS Radio Occultation Measurements of the Ionosphere on CHAMP: Early Results, Geophys. Res. Let., 29, 1457, http://dx.doi.org/10.1029/2001GL014364doi:10.1029/2001GL014364, 2002. Jakowski, N., Leitinger, R., and Angling, M.: Radio occultation techniques for probing the ionosphere, Annals of Geophysics, 47, 1049–1066, 2004. Jakowski, N., Hoque, M. M., and Mayer, C.: A new global TEC model for estimating transionospheric radio wave propagation errors, J. Geod., 85, 965–974, http://dx.doi.org/10.1007/s00190-011-0455-1doi:10.1007/s00190-011-0455-1, 2011a. Jakowski, N., Mayer, C., Hoque, M. M., and Wilken, V.: Total electron content models and their use in ionosphere monitoring, Radio Sci., 46, RS0D18, http://dx.doi.org/10.1029/2010RS004620doi:10.1029/2010RS004620, 2011b. Jones, W. B. and Gallet, R. M.: Representation of diurnal and geographic variations of ionospheric data by numerical methods, ITU Tele-communication Journal, 29, 129–149, 1962. Jones, W. B. and Gallet, R. M.: Representation of diurnal and geographic variations of ionospheric data by numerical methods, ITU Tele-communication Journal, 32, 18–29, 1965. Jones, W. B. and Obitts, D. L.: Global representation of annual and solar cycle variation of \emphfoF2 monthly median 1954–1958, US Institute for Telecommunication Science, Research Report OT/ITSRR 3, National Technical Information Service, COM 75-11143/AS, Springfield, VA, 1970. Kishcha, P. V. and Kochenova, N. A.: Model for the height of the ionosphere maximum in main ionospheric trough zone, Geomagn. Aeronomy, 36, 787–789, 1996. Kumluca, A., Tulunay, E., and Topalli, I.: Temporal and spatial forecasting of ionospheric critical frequency using neural networks, Radio Sci., 34, 1497–1506, 1999. Leitinger, R., Titheridge, J. E., Kirchengast, G., and Rothleitner, W.: A "simple" global empirical model for the F layer of the ionosphere, Wissenschaftliche Berichte 1/1995, IMG, University of Graz, 1995. Liu, C., Zhang, M.-L., Wan, W., Liu, L., and Ning, B.: Modeling M(3000)F2 based on empirical orthogonal function analysis method, Radio Sci., 43, RS1003, http://dx.doi.org/10.1029/2007RS003694doi:10.1029/2007RS003694, 2008. Mandea, M. and Macmillan, S.: International Geomagnetic Reference Field – the eighth generation, Earth Planets Space, 52, 1119–1124, 2000. McKinnell, L. A. and Poole, A. W. V.: Ionospheric variability and electron density profile studies with neural networks, Adv. Space Res., 27, 83–90, 2001. McNamara, L. F., Reinisch, B. W., and Tang, J. S.: Values of \emphhmF2 deduced from automatically scaled ionograms, Adv. Space Res., 7, 53–56, 1987. Nava, B., Coisson, P., and Radicella, S. M.: A new version of the NeQuick ionosphere electron density model, J. Atmos. Solar Terr. Phys., 70, 1856–1862, http://dx.doi.org/10.1016/j.jastp.2008.01.015doi:10.1016/j.jastp.2008.01.015, 2008. Oyeyemi, E. O. and Poole, A. W. V.: Towards the development of a new global \emphfoF2 empirical model using neural networks, Adv. Space Res., 34, 1966–1972, 2004. Oyeyemi, E. O., Poole, A. W. V., and McKinnell, L. A.: On the global model for \emphfoF2 using neural networks, Radio Sci., 40, RS6011, http://dx.doi.org/10.1029/2004RS003223doi:10.1029/2004RS003223, 2005. Piggott, W. R. and Rawer, K.: U.R.S.I. Handbook of Ionogram Interpretation and Reduction, US Department of Commerce, National Oceanic and Atmospheric Administration, Environmental Data Service, Asheville, NC, USA, 325 pp., 1972. Piggott, W. R. and Rawer, K.: U.R.S.I. Handbook of Ionogram Interpretation and Reduction, second ed., World Data Center A for Solar-Terrestrial Physics, Report UAG-23A, 1978. Poole, A. W. V. and Poole, M.: Long-term trends in \emphfoF2 over Grahamstown using neural networks, Ann Geophys., 45, 155–161, 2002. \hack Radicella, S. M. and Leitinger, R.: The evolution of the DGR approach to model electron density profiles, Adv. Space Res., 27, 35–40, http://dx.doi.org/10.1016/S0273-1177(00)00138-1doi:10.1016/S0273-1177(00)00138-1, 2001. Radicella, S. M. and Zhang, M. L.: The improved DGR analytical model of electron density height profile and total electron content in the ionosphere, Annali di Geofisica, XXXVIII, 35–41, 1995. Rush, C. M., Pokempner, M., Anderson, S. F. G., and Perry, J.: Improving ionospheric maps using theoretically derived values of \emphfoF2, Radio Sci., 18, 95–107, 1983. Rush, C. M., Pokempner, M., Anderson, D. N., Stewart, F. G., and Perry, J.: Maps of \emphfoF2 derived from observations and theoretical data, Radio Sci., 19, 1083–1097, 1984. Shimazaki, T.: World daily variability in the height of the maximum electron density of the ionospheric F2-layer, J. Radio Res. Lab. (Japan), 2, 85–97, 1955. Titheridge, J. E.: Re-modeling the ionospheric E region. Kleinheubacher Berichte, 39, 687–696, 1996. Tulunay, E., Özkaptan, C., and Tulunay, Y.: Temporal and spatial forecasting of the \emphfoF2 values up to twenty four hours in advance, Phys. Chem. Earth(c), 25, 281–285, 2000. Wintoft, P. and Cander, L. J. R.: Short-term prediction of \emphfoF2 using time delay neural networks, Phys. Chem. Earth(c), 24, 343–347, 1999. Xenos, T. D.: Neural-network-based prediction techniques for single station modeling and regional mapping of the \emphfoF2 and M(3000)F2 ionospheric characteristics, Nonlin. Processes Geophys., 9, 477–486, http://dx.doi.org/10.5194/npg-9-477-2002doi:10.5194/npg-9-477-2002, 2002. Yue, X., Schreiner, W. S., Lei, J., Sokolovskiy, S. V., Rocken, C., Hunt, D. C., and Kuo, Y.-H.: Error analysis of Abel retrieved electron density profiles from radio occultation measurements, Ann. Geophys., 28, 217–222, http://dx.doi.org/10.5194/angeo-28-217-2010doi:10.5194/angeo-28-217-2010, 2010. Zhang, S.-R., Oliver, W. L., Holt, J. M., and Fukao, S.: Ionospheric data assimilation: comparison of extracted parameters using full density profiles and key parameters, J. Geophys. Res., 108, 1131, http://dx.doi.org/10.1029/2002JA009521doi:10.1029/2002JA009521, 2003. Zhang, M.-L., Liu, C., Wan, W., Liu, L., and Ning, B.: A global model of the ionospheric F2 peak height based on EOF analysis, Ann. Geophys., 27, 3203–3212, http://dx.doi.org/10.5194/angeo-27-3203-2009doi:10.5194/angeo-27-3203-2009, 2009.