IMAGING OF STRUCTURES IN THE HIGH-LATITUDE IONOSPHERE - MODEL COMPARISONS

The tomographic reconstruction technique generates a two-dimensional l atitude versus height electron density distribution from sets of slant total electron content measurements (TEC) along ray paths between bea con satellites and ground-based radio receivers. In this note, the tec hnique is applied to TEC values obtained from data simulated by the Sh effield/UCL/SEL Coupled Thermosphere/Ionosphere/Model (CTIM). A compar ison of the resulting reconstructed image with the 'input' modelled da ta allows for verification of the reconstruction technique. All the fe atures of the high-latitude ionosphere in the model data are reproduce d well in the tomographic image. Reconstructed vertical TEC values fol low closely the modelled values, with the F-layer maximum density (NmF 2) agreeing generally within about 10%. The method has also been able successfully to reproduce underlying auroral-E ionisation over a restr icted latitudinal range in part of the image. The height of the F2 pea k is generally in agreement to within about the vertical image resolut ion (25 km).