Short-term prediction of ionospheric parameters based on auto-correlation analysis

A prediction method based on a simple auto-regressive model has been developed for short-term prediction of ionospheric characteristics. The method determines the auto-correlation function for the hourly values of the parameter of interest, using the time series from the previous 25 days. The resulting weighting coefficients can then be used to forecast future values of the parameter. The method has been applied to predict f0F2 up to 24 h ahead for stations Uppsala, Slough, Poitiers and Sofia. Error statistics are presente

Short-term prediction of ionospheric parameters based on auto-correlation analysis

A prediction method based on a simple auto-regressive model has been developed for short-term prediction of ionospheric characteristics. The method determines the auto-correlation function for the hourly values of the parameter of interest, using the time series from the previous 25 days. The resulting weighting coefficients can then be used to forecast future values of the parameter. The method has been applied to predict f0F2 up to 24 h ahead for stations Uppsala, Slough, Poitiers and Sofia. Error statistics are presente

Assessment of the Topside Sounder Model Profiler performance

In this investigation we apply a model-assisted technique to construct the topside electron density profile.This technique is based on the Topside Sounder Model (TSM), which provides the plasma scale height (Ts), O+/H+ transition height (Th), and their ratio Rt=Ts/Th, derived from topside sounder data of Alouette and ISIS satellites. The Topside Sounder Model Profiler (TSMP) incorporates TSM and uses the model quantities as anchor points for the construction of topside density (Ne) profiles. In the present version, TSMP takes the F2 peak characteristics – foF2, hmF2, and the neutral scale height HmF2 at hmF2– from ground-based Digisonde measurements. Previous investigations have demonstrated that HmF2, used in the Digisondes to construct the topside profiles, is smaller than the topside scale height extracted from topside sounder profiles, at middle latitudes. Therefore the Digisonde scale heights have to be adjusted by a factor estimated for each Digisonde location. When the Digisonde scale height is corrected by this factor, the reconstructed topside profiles are close to those provided by TSM. The new TSMP/Digisonde assisted technique of topside profile construction can improve the topside profiles from the worldwide network of Digisonde sounders. Extensive comparison and verification with ground and satellite derived TEC assesses the performance of the proposed technique. A first indication from the comparison with CHAMP reconstructed profiles shows lower density of TSMP/Digisonde profiles between 400 km and 2000 km. Further comparisons with Vary-Chap profiles and RPI plasmagrams from the IMAGE satellite will lead to useful conclusions concerning the performance of the proposed method up to geosynchronous altitudes

DIAS effective sunspot number as an indicator of the ionospheric activity level over Europe

DIAS (European Digital Upper Atmosphere Server) effective sunspot number – R12eff was recently introduced as a proxy of the ionospheric conditions over Europe for regional ionospheric mapping purposes. Although a pre-processing step for the real-time update of the Simplified Ionospheric Regional Model (SIRM) to real-time conditions, R12eff is available in real time by DIAS system (http://dias.space.noa.gr) for independent operational use. In this paper we discuss the efficiency of R12eff to specify ionospheric conditions over Europe. For this purpose, the diurnal R12eff’s reference pattern was determined on monthly basis and for different solar cycle phases. The deviation of the real-time R12eff estimates from the reference values, ΔR12eff was found to be highly correlated with the foF2 storm-time disturbances, especially during large scale effects indicating that DIAS-R12eff can provide a reliable estimator of the ionospheric activity level over a substantial part of Europe and a powerful tool for ionospheric specification applications.Published491-5121.7. Osservazioni di alta e media atmosfera3.9. Fisica della magnetosfera, ionosfera e meteorologia spazialeJCR Journalrestricte