In the master thesis we present results of the program, written in the Python environment, that could be used to determine the visibility of satellites by considering the obstacles in the vicinity of the specific point. The solution is based on the acquisition of the two-line NORAD elements, their use in the model SDP4 and final celestial to terrestrial coordinate transformation. Furthermore, the calculation of azimuths and elevation angles is performed to present the visibility of satellites graphically (skyplots). From the fisheye-images, visible sky-masks are produced. The overlaps of the visible sky-masks and the sky-plots lead to final goal, i.e. to determine visible satellites at specific location at different epochs based of the knowledge of the obstacles in the vicinity of the point. The master thesis deals with the satellite visibility situations in different periods of 2019 spring vegetation. For the GNSS satellites, GDOP factors can be computed, which mathematically describe the satellite topology on the positional quality determination. Since NORAD two-line elements are available for any space object, the solution can be used to present the visibility of other space objects. The master thesis idea is based on the fisheye-image acquisition of obstacles with simple gadgets (360° camera for cell-phones), to easily evaluate the possibility of GNSS-navigation at the specific moment as well as in near-future or to obtain satellite visibility information used in various remote-sensing.
|
