STRUCTURE AND DYNAMICS OF THE SOLAR CORONA DURING DIFFERENT PHASES OF SOLAR ACTIVITY

Optical observations of artificial satellites of the Earth are limited to the time when the satellite is in sunlight while the observer is on the dark side of the Earth.For low Earth orbit (LO) satellites, the observation time is limited to astronomical twilight conditions, usually an hour or two after sunset and before dawn.In addition, LO objects have a relatively high angular velocity and pass quickly through the telescope's field of view.This limits the time for frame integration possible for LO objects.Radars have an advantage over optical methods for measuring LO satellites, as large amounts of microwave power can be used to obtain high signal reflectance, and radar observations can be performed continuously, without being limited by the time and position of the Sun and the state of the earth's atmosphere.In particular, the European Development Guidelines Space Surveillance and Tracking (SST) are considered.The main efforts are being made to build an operational network for SST and Space Debris (SD) observations.The types of observations have been demonstrated: radar, optical and laser.Also, the type of SST and SD observations is defined:-Panoramic observations for object detection using wide-angle light-eyed lenses; -Determination of precise coordinates with the use of accurately directed optical telescopes;-Determining the exact distance to them with a laser signal; -Optical identification of the silhouette of satellites and their processed components.Discussion on development of observation networks in Europe and the participation of Bulgarian SST and SD observers to them were discussed.The individual stages of data acquisition and storage, cataloging of objects and details are shown.