Error sources and travel time residuals in plasmaspheric whistler interpretation

Systematic travel time residuals which appear in the interpretation of observed whistlers by curve fitting are studied using simulations. It is found that the residuals originate from the commonly used approximations in the refractive index and ray path of whistler mode waves. The approximations also lead to errors in the diagnostics of plasmaspheric electron density by whistlers. The effects of other error sources such as random measurement errors and the possible application of residual analysis with digital matched filtering are discussed.