Ionospheric modification

This report serves as an introduction to ionospheric modification, that is deliberate creation of instabilities and other effects in the ionosphere by injection of radio waves. The necessity of high transmitted power in the vertical direction requires purposely built facilities. Modification of the ionosphere give rise to a number of effects which may have military applications. Among these are the acceleration of electrons which, due to secondary processes, generate IR radiation over an area and the generation of ELF for communication with submarines or detection of underground facilities. The third generation of facilities represented by HAARP, under construction in Alaska, seem to be aimed at developing effects demonstrated earlier into military useful applications. The Swedish perspective can be viewed from three aspects. The ability to mitigate threats, capabilities and a knowledge base. The first two aspects depend on the ambitions of a future Swedish defense while the last aspect is a recommended baseline in order to identify threats and possibilities in the future.