ИСТИНА

A review of recent results on conjugate ground-spacecraft observations of various types of VLF emissions such as quasi-periodic and chorus emissions will be given. For quasi-periodic emission, it will be shown that quasi-parallel propagation with respect to the geomagnetic field and the appopriate Poynting flux direction away from the equator are not sufficient to infer the location of a spacecraft within a generation region of such signals. Using the whistler mode growth rate calculations serve as important tool for identifying the spacecraft passage in a probable generation region. For chorus emissions we demonstrate a persistence of a discrete element structure for a two-hop pass from a generation region to the ground and back to the magnetisphere after the reflection from the ionosphere or from the ground. In all cases the use of propagation properties of VLF emissions detected on the ground can greatly help in resolving ambiguities with respect to the possible location of the signal generation region. Examples of simulations of related wave-particle interactions will be given.