2004), Spatial and temporal properties of AKR burst emission derived from Cluster WBD VLBI studies, Ann

Part of Special Issue “Spatio-temporal analysis and multipoint measurements in space” Abstract. We have determined the locations of over 6000 in-dividual auroral kilometric radiation (AKR) bursts between July 2002 and May 2003 using a very long baseline inter-ferometer (VLBI) array. Burst locations were determined by triangulation using differential delays from cross-correlated Cluster WBD waveforms. Typical position uncertainties are 200–400 km in the plane normal to the source-spacecraft line, but much larger along this line. The AKR bursts are generally located above the auroral zone with a strong pref-erence for the evening sector (22:00 MLT ±2 h). However, a few epochs imaged during the austral summer have loci in the daytime sector, especially near 15:00 MLT. There is marginal evidence for a small N-S hemispheric asymmetry in mean MLT and invariant latitude. Key words. Magnetospheric physics (auroral phenomena) – Radio science (interferometry) – Space plasma physics (in-struments and techniques