SOME ASPECTS OF COST 238 (PRIME) STUDIES DIRECTED TOWARDS IMPROVED REGIONAL MAPS OF FOF2 AND M(3000)F2 OVER EUROPE

Errors in the determination of the anchor points foF2 and M(3000)F2 are a major cause of inaccuracy in specifying the IRI electron concentration profile. The accuracy with which current internationally accepted global long-term maps can predict these ionospheric characteristics falls short of what is potentially achievable within regions containing closely spaced vertical sounding stations such as over Europe. Project PRIME aims to generate improved reference European maps, but first a number of important questions need to be addressed. These include the determination of the most appropriate latitude coordinate system and how to interface such new maps with established global maps outside the region studied, particularly for ray-tracing applications where gradient discontinuities are unacceptable. The following is a description of work carried out to date in these areas.