The decametric radiowaves propagation in the ionospheric plasma was considered.  Bicharacteristic system of equations was used in the modeling  ray structures.  This  system, which allows finding the ray paths with  great precision,  was obtained  by D.S. Lukin.   Models of the ionosphere  with horizontal gradients were used  in the calculations; local inhomogeneities, such as reduced  electron density in the maximum  layer and  increased  electron density below the maximum layer,  were taken into account.  The  features of shortwave propagation,  such as getting  a wave of interlayer  channel,  distribution  and out of it, reflection of waves from different ionospheric  layers  were explored.  Was  shown that the rays can be ejected from the field of distribution and  curled  when hit in the inhomogeneity of the ionosphere.  The  formation of caustic surfaces  and  its dynamics  were studied.  The  radiowaves  propagation in the Earth’s ionosphere was studied.   This  ionosphere  profiles were restored  the scientific  group led by Professor V.E. Kunitsyn by radiotomography method based on real observations.  Ray structures in the area of “equatorial anomaly” were built.  The  models,  both including  and  excluding  the effect of Earth’s magnetic field and  the influence of the equatorial anomaly were considered.  Ray structures at the different positions of the radiation source, as well as different operating frequency,  were investigated.  Dynamic  model of the ray’s propagation was developed.

Radioondas  decamétricas; el sistema bicaracterístico; plasma ionosférico; anomalía ecuatorial; estructuras radiales