Выступление на научной ассамблее комитета по космическим исследованиям
Ассистент межвузовской кафедры космических исследований, к.ф.-м.н. Пётр Николаев выступил на 43-й научной ассамблее комитета по космическим исследованиям (COSPAR) с сообщением "Fast Two-Dimensional Ionosphere Tomography Using Inter-Satellite Measurement". С записью выступления и тезисами доклада можно ознакомиться на данной странице.
Fast Two-Dimensional Ionosphere Tomography Using Inter-Satellite Measurements
In our opinion, the most promising system of the tomographic monitoring of the ionospheric state is an orbital constellation, satellites of which have receivers and transmitters measuring the total electron content (TEC) on inter-satellite line-of-sights. To solve the number of applied problems, for instance a determination of precursors of natural disasters, which can be reflected by the ionosphere, it is necessary to quickly carry out a remote sensing of the ionosphere to obtain an information about its state in real time. This cause motivates us to obtain the electron density profile directly in orbit, but tomographic algorithms used for that significantly loads an on-board computer of the satellite. Thus, the algebraic reconstruction technique (ART), which has become a classic in the radio tomography of the ionosphere for almost 30 years, cannot be used on board any satellite in the constellation due to its computational complexity. For this reason, the development of new fast methods for the radio tomography of the ionosphere is required.
We developed a novel method, which processes measurements of the ionospheric TEC obtained by satellites, for the fast estimation of the ionospheric electron density profile in the plane of the low-orbit satellite constellation. This method can be implemented on board the satellite due to its computational simplicity. The method consists of a sequential solution of the following problems: the formation of the initial approximation for the electron density profile using measurements of the TEC; the restoration of missing data in the Radon image using a priori information about its form; the reconstruction of electronic density by the convolution algorithm, which has the most computational simplicity among transform methods in the computerized tomography. The developed method increases the speed of the reconstruction of the electron density profile by more than 60 times compared with ART and allows performing the reconstruction directly on board the satellite. We performed a number of numerical simulations of the method, which showed that errors in the estimation of the electron density profile do not exceed 20%, which allows us to detect anomalies in the ionosphere, such as precursors of natural disasters.
This work was supported by state funding allocated to the winners of the competition of scientific laboratories of higher educational institutions subordinate to the Ministry of Education and Science of Russia (project No. 0777-2020-0018)