Improving ionospheric maps using theoretically derived values of f₀F₂

Abstract

The results of a study to improve the global maps of monthly median values of the F2 region critical frequency, f0 F2, using values determined from a theoretical model are presented. Values of the midlatitude F2 region critical frequency that could be used to improve the prediction of f0 F2 in regions of the earth inaccessible to ground‐based measurements were obtained. This was accomplished by including in the theoretical calculations realistic physical processes along with a realistic geomagnetic field model. Parameters were adjusted so that agreement was achieved between calculated and observed f0 F2 values as a function of local time at different stations, and then these same input parameters (i.e., neutral wind field, and neutral atmospheric model) were assumed valid at all regions of interest where the major difference is the geomagnetic field line configuration. Coefficients that yield global representations of f0 F2 were then determined using the theoretically derived f0 F2 values, and the predicted critical frequencies were compared with observed values to estimate the degree of improvement.

Maps of <I>fo</I>F2, <I>hm</I>F2, and plasma frequency above F2-layer peak in the night-time low-latitude ionosphere derived from Intercosmos-19 satellite topside sounding data

“…Gallet, 1962, 1965;Rush et al, 1983Rush et al, , 1984Fox and McNamara, 1988;Bradley, 1990;Rawer, 1995;Bilitza et al, 1996;Bradley et al, 2004). In fact, Intercosmos-19 provides the possibility of reconstructing the three-dimensional distribution of Ne in the topside ionosphere.…”

Testing of the international reference ionosphere model using the data of dual-frequency satellite altimeters “Topex”/“Poseidon” and “Jason-1”

“…Both sets of coefficients were obtained by one algorithm, but are based on different data sets [24]. Theoretical aeronomy data were used for the URSI coefficients [25], which made it possible to improve a description of the ionosphere above the ocean and in the Southern hemisphere.…”

Near-real time foF2 predictions using neural networks

“…To achieve this task a number of empirical ionospheric models have been developed. Among these models are those of Ching and Chiu (1973), Chiu (1975), Bent et al (1978), Rush et al (1983Rush et al ( , 1984, Fox and McNamara (1988), Fuller-Rowell et al (2000) and Bilitza (2001). A comprehensive survey of these models has been provided by Bilitza (2002).…”