In order to understand the dynamics and response of the ionosphere to various energy inputs requires a knowledge of the ways in which one type of atomic or molecular ion interacts with the other atmospheric ion and neutral constituents. This investigation makes use of state of the art laboratory instrumentation for photo-ion and photo-electron coincidence techniques. Many fundamental absolute cross-sections that involve charge transfer between selected specific energetic states of O+ and neutral constituents such as N2, O2 and CO2 producing specific excited states of N2+, NO+, O2+ and CO+ will be investigated.
