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Part of Special Issue "Precursory phenomena, seismic hazard evaluation and seismo-tectonic electromagnetic effects" Abstract. The spread-E s phenomenon which appears as diffusivity of the traces of sporadic E-layers on the ionogrammes of vertical sounding stations and which reflects the turbulization of the sporadic layers E s is studied in connection with earthquake preparation processes. Spread-E s data obtained at night every 15 min by the midlatitudinal vertical sounding station of the ionosphere in Dushanbe (φ=38.5 • N, λ=68.8 • E) are analysed. Groups of earthquakes with different magnitudes and different distances between the epicenter and the sounding station are considered. A statistical analysis of the obtained results is performed. It is shown that during the three nights before an earthquake, spread-E s phenomena are observed more often than during the forth, fifth and sixth nights before the event. This effect is found to depend on both the magnitude of the earthquake and the distance between the epicenter and the sounding station.

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The purpose of the experimental study presented in the paper is to generate new knowledge about the possibility of using unmanned aerial vehicles to survey buildings and structures for subsequent extraction of information about their condition in hard-to-reach or remote places. As objects for the pilot experiment, the following were selected: a residential building in an urban environment that has been destroyed during operation; an object of unfinished construction; a roadway on the carriageway. An unmanned aerial vehicle of the model: DJI Mavic Air was used to survey the objects. The results of the study of objects are recorded in the form of photo and video streams for each object. Comparison of the results of the inspection of objects by experts and unmanned aerial vehicles showed the possibility and necessity of using new means to collect information about the condition of buildings and structures. The primary processing of the obtained images revealed their features: the effect of illumination on the color characteristics of the object of study; the presence of a textural component that complicates the process of separating the defect from the background; the presence of objects in the image that are not related to the elements of surface destruction; the change in the initial size of the object over time. The detected features of the images allow the use of standard algorithms and processing and require the synthesis of unique trajectories of their application.

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