Репозитарій ОНУ імені І.І.Мечникова

Перегляд за Автор "Shakun, Leonid S."

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Analysis of near-earth resident space objects visibility conditions from optical ground stations
(2019) Shakun, Leonid S.; Korobeinikova, E. A.; Koshkin, Nikolay I.; Kozhukhov, O.; Kozhukhov, D.; Piskun, O.; Strakhova, Svitlana I.; Кошкін, Микола Іванович; Кошкин, Николай Иванович
The continuous monitoring of space object positions in near-Earth space is necessary for tasks of: -the collision prevention of an active satellite with other satellites or space debris objects; -the cleaning Near-Earth space from inactive satellites and space debris; -the planning of new satellite launches.
Atlas of light curves of space objects
(2021) Koshkin, Mykola I.; Shakun, Leonid S.; Korobeinikova, E. A.; Strakhova, S. L.; Melikyants, S. M.; Terpan, S. S.; Golubovskaya, T. A.; Dragomiretsky, V. V.; Ryabov, A. V.; Кошкін, Микола Іванович
Determination of the rotation parameters of reference artificial satellite AJISAI and synchronization of the photometric channels
(Astroprint, 2010) Koshkin, Nikolay I.; Korobeinikova, E. A.; Strakhova, S. L.; Shakun, Leonid S.; Lopachenko, V. V.; Кошкин, Николай Иванович; Кошкін, Микола Іванович
The aim of the present study is to obtain the adjusted current coordinates of the rotation pole of artificial satellite Ajisai and the up-to-date sidereal period of its rotation. To do that, the light curves obtained in Odessa during 2009-2010 are considered. Using both the Ajisai pole’s coordinates and the reduced null point of the hardware-based time scale, has made it possible to improve the timing of the observed flashes of its brightness. By the accurate timing of the simultaneous photometric observations of Ajisai satellite the photometric channels synchronization at the stations in Odessa and Eupatoria is accomplished. The further photometric observations of that satellite are necessary to construct a theory of its rotation about the centre of mass; that will allow of its using as a reference source of the time-calibrated optical signals for any ground-based observatories.
External comparison satellite positions obtained by the network of passive correlation ranging of geostationary telecommunication satellites
(Одеський національний університет імені І. І. Мечникова, 2018) Bushuev, F. I.; Kaliuzhnyi, M. P.; Mazhaev, O.; Shulga, O. V.; Shakun, Leonid S.; Bezrukovs, Vladislavs; Reznichenko, O.; Moskalenko, Sergiy; Malynovskyi, Ye.
Network of passive correlation ranging contains of five stations located in Ukraine and Latvia. It has been created at the initiative of the RI “Mykolaiv Astronomical Observatory” to have independent means to track the future Ukrainian geostationary satellite “Lybid”. Regular observations of the geostationary telecommunication satellite “Eutelsat-13B” has being carried out by the network since February 2015. A catalog of daily orbital elements of the tracked satellite has been created using the network observations. The analytical model SGP4/SDP4 of satellite motion and a numerical model of integration of equations of satellite motion are used to determine the orbital elements. The numerical model takes into account the gravitational attraction of the Sun and Moon, and nonspherical Earth. Software of the orbital elements determinations has been developed by the RI “Astronomical Observatory” of the Mechnikov Odesa National University. Satellite positions calculated using orbital elements from the catalog were compared with ones obtained using the NORAD space-track.org site and optical observations performed by the Ukrainian Network of Optical Stations. The satellite position comparisons were carried out only for time intervals of unperturbed motion of the satellite. The free motion time intervals were determined using the algorithm that had been tested using satellite owner data about the moments of satellite maneuvers. Herewith values of right ascension and declination were compared. Regular (mean) and random (standard deviation) values of the residuals are given in the report.
Features of Kotlin orbit estimation library
(Одеський національний університет імені І. І. Мечникова, 2018) Shakun, Leonid S.; Шакун, Леонід С.
Since the launch of Sputnik 1, the number of objects in near-earth orbit has been constantly increasing. The growth of number of these objects increases the risk of their collisions with existing satellites and ones which will be launched, that can be accompanied by their failure or even destruction. Most space agencies and many countries have their own space surveillance networks. These networks continually measure the positions of known objects, find new ones and predict their future positions. It is necessary to know the position of the objects with an accuracy of up to the characteristic size of the operating satellites (about 10 cm or more) to prevent collisions. Today, this task can be solved only for a small number of reference satellites and only for the past. The calculation of the objects positions in near-Earth space requires the implementation of complex models of the Earth motion and a space object using many factors affecting the final result. Some of these factors, for example, the atmospheric density and the attitude of the satellite in the space, are not well predicted by modern models and require constant refinement from observations. Ukrainian Optical Facilities for Near-Earth Space Surveillance Network (UMOS) is used to surveillance and study near-Earth space in Ukraine. There are many practical tasks that require knowledge of the positions of the space objects. The different software solutions are being applied to solve them. All of them must implement motion models of near-Earth space objects, the Earth and the main bodies of the Solar System for their needs. Space dynamics libraries are developed to implement these models. Orekit is one of these libraries. The Kotlin Orbit Estimation Library (KOrbEstLib) is built on the features of Orekit and extends them. KOrbEstLib expands the set of input and output data types, implementing the support of a number of Ukrainian and international data formats, in particular, the formats used in the UMOS network. In addition, KOrbEstLib offers an alternative implementation for estimating the parameters of the motion model of space objects in comparison with Orekit. This paper discusses a number of implementation features of the KOrbEstLib.
International network of passive correlation ranging for orbit determination of a geostationary satellite
(Одеський національний університет імені І. І. Мечникова, 2016) Kaliuzhnyi, Mykola; Bushuev, Felix; Shulga, Oleksandr; Sybiryakova, Yevgeniya; Shakun, Leonid S.; Bezrukovs, Vladislavs; Moskalenko, Sergiy; Kulishenko, Vladislav; Malynovskyi, Yevgen
An international network of passive correlation ranging of a geostationary telecommunication satellite is considered in the article. The network is developed by the RI "MAO". The network consists of five spatially separated stations of synchronized reception of DVB-S signals of digital satellite TV. The stations are located in Ukraine and Latvia. The time difference of arrival (TDOA) on the network stations of the DVB-S signals, radiated by the satellite, is a measured parameter. The results of TDOA estimation obtained by the network in May-August 2016 are presented in the article. Orbital parameters of the tracked satellite are determined using measured values of the TDOA and two models of satellite motion: the analytical model SGP4/SDP4 and the model of numerical integration of the equations of satellite motion. Both models are realized using the free low-level space dynamics library OREKIT (ORbit Extrapolation KIT).
International network of passive correlation ranging for orbit determination of a geostationary satellite
(Одеський національний університет імені І. І. Мечникова, 2016) Kaliuzhnyi, Mykola; Bushuev, Felix; Shulga, Oleksandr; Sybiryakova, Yevgeniya; Shakun, Leonid S.; Bezrukovs, Vladislavs; Moskalenko, Sergiy; Kulishenko, Vladislav; Malynovskyi, Yevgen
An international network of passive correlation ranging of a geostationary telecommunication satellite is considered in the article. The network is developed by the RI "MAO". The network consists of five spatially separated stations of synchronized reception of DVB-S signals of digital satellite TV. The stations are located in Ukraine and Latvia. The time difference of arrival (TDOA) on the network stations of the DVB-S signals, radiated by the satellite, is a measured parameter. The results of TDOA estimation obtained by the network in May-August 2016 are presented in the article. Orbital parameters of the tracked satellite are determined using measured values of the TDOA and two models of satellite motion: the analytical model SGP4/SDP4 and the model of numerical integration of the equations of satellite motion. Both models are realized using the free low-level space dynamics library OREKIT (ORbit Extrapolation KIT).
LIGHT POLLUTION IN LEO-SATELLITE TRACKING
(Astroprint, 2015) Shakun, Leonid S.; Marsakova, V. I.; Golubovskaya, T. A.; Terpan, S. S.; Melikyants, S. M.; Korobeinikova, E. A.
Because of the high level of the light pollution in Odessa city, only the observations of LEO (low Earth orbit)-satellites are performed in the main office of the Astronomical observatory of Odessa National University named after I.I. Mechnikov. As the one of the observation results we obtain the sky background measurements along the satellite’s way through the sky (at different azimuths and altitudes that change during the satellite tracking). We propose the method of irregular extinction changes diagnostics that realized by using the different data filtration methods. Also as the result of our analysis of these observations we present azimuth-altitude diagram of sky background that shows the most significant light pollution at the north-western and northern directions caused by the Port of Odessa and the stadium “Chernomorets”.
Monitoring of space debris rotation based on photometry
(Одеський національний університет імені І. І. Мечникова, 2018) Koshkin, Nikolay I.; Shakun, Leonid S.; Korobeinikova, E. A.; Melikyants, S. M.; Strakhova, S. L.; Dragomiretsky, V. V.; Ryabov, A. V.; Golubovskaya, T. A.; Terpan, S. S.; Кошкин, Николай Иванович; Кошкін, Микола Іванович
The number of spacecraft and space debris (SD) in orbit has become so great that there is a real threat to flight safety. The task of precision calculation of the upcoming positions of any space objects (SO) in orbit in order to predict dangerous mutual approaches and to solve practical tasks has become topical. For the development of a modern orbit propagation model and the associated unified forecast of the evolution of orientation and rotation of an uncontrolled satellite, it is necessary to rely on long-term series of high-quality measurements and their analysis. At present, the direction of research on determining the state of SO rotation around a center of mass has become more and more developed. In our work, we analyze the results of photometric observations of several large objects of space debris obtained at the Astronomical Observatory of Odessa University using the KT-50 telescope during the last six years or more. The results of the evolution of the rotation rate and orientation of the Topex/Poseidon, Envisat, Oicets, Cosmos-2487 (Kondor- E) and Sich-2 satellites are presented.
Monitoring of the inoperative Envisat satellite’s behaviour
(Astroprint, 2013) Shakun, Leonid S.; Koshkin, Nikolay I.; Korobeinikova, E. A.; Melikyants, S. M.; Strakhova, S. L.; Terpan, S. S.; Кошкин, Николай Иванович; Кошкін, Микола Іванович
New positions data and light curves were received for the inoperative Envisat spacecraft still in orbit. The satellite pole and sidereal rotation period were determined on the base of the photometric data for the period from April to August 2013. The presence of a precession of the Envisat rotation axis was deduced.
Monitoring the artificial space objects with Ukrainian network of optical stations
(Одеський національний університет імені І. І. Мечникова, 2021) Romanyuk, Ya. O.; Shulga, O. V.; Shakun, Leonid S.; Koshkin, Nikolay I.; Кошкін, Микола Іванович; Кошкин, Николай Иванович; Vovchyk, Ye. B.; Bilinsky, А. І.; Kozyryev, Y. S.; Kulichenko, M. O.; Kriuchkovsky, V. F.; Kashuba, V. I.; Korobeynikova, E. A.; Меlikyants, S. M.; Strakhova, S. L.; Теrpan, S. S.; Golubovskaya, T. A.; Martyniuk-Lototskiy, K. P.; Nogacz, R. T.; Epishev, V. P.; Kudak, V. I.; Neubauer, І. F.; Perig, V. М.; Prysiazhnyi, V. I.; Ozeryan, A. P.; Kozhukhov, O. M.; Kozhukhov, D. M.; Ivaschenko, Yu. M.
The article describes the successes and challenges of the Ukrainian network of optical stations (UMOS) in recent years in the field of astrometric observations of artificial space objects both in low-Earth orbit (LEO) and geostationary Earth orbit (GEO). UMOS was established in 2012 as a joint partnership of organizations interested in satellite observations for scientific purposes and practical near Earth space monitoring. The main purpose of the UMOS has been (and still is) to combine scientific and technical means with regular optical (positional and / or non-positional) observation. The short list of equipment of the UMOS members are given in the tables. The programs for observations, used methods and obtained results are described in the paper. In conclusion, the advantages of observations of artificial space objects by means of a network are summarized. The experience of UMOS and main results obtained by UMOS can be considered as the first step to create the SSA system of Ukraine
Observations of the mutual phenomena of the Galilean moons in 2009
(Astroprint, 2010) Koshkin, Nikolay I.; Korobeinikova, E. A.; Shakun, Leonid S.; Dorokhov, N.; Doan, D.L.; Manh, T.N.; Minh, T.N.; Udovichenko, S. N.; Bondarenko, Yu. N.; Kashuba, V. I.; Klabukova, A.; Кошкин, Николай Иванович; Кошкін, Микола Іванович
The instrumental and ephemeris preparation for the photometric observations of the mutual phenomena in the system of planetary satellites was conducted within the PHEMU09 project. Several reliable light curves and more than two tens of preparatory photometric observations of various mutual phenomena in the Jovian system were obtained. The observation data were processed, and the moments of the greatest phases of the phenomena were defined. The difference of moments of the observed greatest phases of the phenomena and the ephemerides, computed by the theory of V. Lainey, is about 0.02^0.5 minutes. To construct an improved theory of motion of the Jovian moons, the observations are to be used for the concluding processing in the IMCCE (Institute de Mecanique et de calcul des ephemerides, France) that coordinates the PHEMU09 campaign.
Period variations and possible third components in the eclipsing binaries AH Tauri and ZZ Cassiopeiae
(Одеський національний університет імені І. І. Мечникова, 2018) Tvardovskyi, D. E.; Marsakova, V. I.; Andronov, Ivan L.; Shakun, Leonid S.; Твардовський, Д. Є.; Маршакова, В. І.; Андронов, Іван Л.; Шакун, Леонід С.
In our research, we investigated two variable stars: AH Tau and ZZ Cas. They are eclipsing binary stars of W Ursae Majories and 􀁅 Lyrae types. The period between eclipses of these stars changes with time. The reason for steady changes of the period could be the mass transfer (the flow of matter) between components of these stellar systems. For ZZ Cas the changes of the period are cyclic. That is why we assume the cyclic changes could be caused by the presence of the hypothetical third component (either a small star or a large planet). The cyclic changes of the period for AH Tau superimpose on steady ones (the period decrease). Thus we assume the third component and mass transfer are present. We also assume that the third components do not take part in the eclipses. However, due to their gravity, they make the visible close binary systems rotate and become closer or further to an observer. This explanation is called Light-Time Effect (LTE). Generally, an orbit of a third component is not a circle, but an ellipse and it is inclined relatively to the observer’s line of sight. Using special plot called O-C curve we estimated the parameters of a third component’s orbit such as a semi-major axis, an eccentricity, angles of orientation and a period of a third component’s rotation. The O-C curve is the plot which shows how the difference between an observed and calculated moment of minimal brightness changes during a long period of time (usually it is several decades). To do this we created a modeling computer program using the computer language Python. In addition, we can calculate errors of third component’s orbit parameters and even estimate its mass. The values of masses of the third components within errors of calculations show that the third components are probably stars. All these calculations were made using all available data from international database BRNO (Brno Regional Network for Observers). Moreover, we used moments of minima which we calculated as the result of observation processing from AAVSO database (American Association of Variable Stars Observers). These results are provided in the tables and plots.
Simulation of the orbiting spacecraft to analysis and understand their rotation based on photometry
(Одеський національний університет імені І. І. Мечникова, 2019) Koshkin, Nikolay I.; Melikyants, S. M.; Korobeinikova, E. A.; Shakun, Leonid S.; Strakhova, Svitlana I.; Kashuba, V.; Romanyuk, Ya.; Terpan, S. S.; Кошкін, Микола Іванович; Кошкин, Николай Иванович; Шакун, Леонід С.
Analysis of the photometric information allows to determine the parameters of spacecraft rotation. We will consider the light curves of a rotating satellite. Smooth changes in brightness, which are caused by diffuse scattering of sunlight, are characterized by the amplitude, quantity, shape and asymmetry of brightness variation during the rotation period of the body. In addition, the so-called “specular” flashes of light of very large amplitude are present on light curves. By analyzing the observed light curves of the inactive satellites Topex/Poseidon and Sich-2, the determination of pole orientation these objects in space is demonstrated. To interpret the light curve's contained information, we are planning to creat optical-geometrical models of this satellite and simulated geometrical conditions by its orbit passages. Further comparison of the model and observed light curves should allow us to confirm the correctness of the satellite attitude determination. For the simulation, we used the MaxScript programming language, which allows to create a satellite model, and simulate the opticalgeometric conditions of its passage, including the complex rotation of the spacecraft.
The observations of artificial satellites and space debris using KT-50 telescope in the Odessa University
(Одеський національний університет імені І. І. Мечникова, 2016) Shakun, Leonid S.; Koshkin, Nikolay I.; Korobeinikova, E. A.; Melikyants, S. M.; Strakhova, S. L.; Terpan, S. S.; Burlak, N.; Golubovskaya, T. A.; Dragomiretsky, V. V.; Ryabov, A. V.; Кошкин, Николай Иванович; Кошкін, Микола Іванович
In paper the equipment, images analysis techniques in the frame and the method of the satellite brightness estimation in the standard photometric system are describes. Within two years, on the KT-50 telescope were obtained measurements of about two hundred objects in more than 2,000 passages. The results of statistical analysis of actual data observations array in 2015 and 2016 are given.
The photometric model of artificial satellite AJISAI and determination of its rotation period
(Astroprint, 2012) Korobeinikova, E. A.; Koshkin, Nikolay I.; Shakun, Leonid S.; Burlak, N.; Melikyants, S. M.; Terpan, S. S.; Strakhova, S. L.; Кошкин, Николай Иванович; Кошкін, Микола Іванович
ABSTRACT. Photometry is used to make remote diagnostics of an artificial satellite’s motion around its centre of mass. Experimental satellite Ajisai was designed to explore the effects of the space factors, such as gravitation and magnetic fields, solar radiation and others, on its orbital motion and rotation. In the present study we consider the use of peculiar light curves of Ajisai, exhibiting a complex sequence of momentary flashes, for precise determination of the rotation period and velocity variations. For the first time, on the basis of the high-speed photometry, the model of placement of mirrors on the satellite’s surface was designed to carry out further analysis of its kinematics.
The research of variation of the period and precession of the rotation axis of Egs (Ajisai) satellite by using photometric measurement
(Astroprint, 2014) Burlak, N.; Koshkin, Nikolay I.; Korobeinikova, E. A.; Melikyants, S. M.; Shakun, Leonid S.; Strakhova, S. L.; Кошкин, Николай Иванович; Кошкін, Микола Іванович
The light curves of EGS Ajisai with temporal resolution of 20 ms referred to the time scale UTC (GPS) with an error of at most 0.1 ms were obtained. The observed flashes are produced when the mirrors which cover the spinning satellite’s surface reflect off the sunlight. In previous paper the analysis of sequence of flashes allowed of reconstructing the arrangement and orientation of the mirrors, i.e. developing an optogeometric model of the satellite (Korobeynikova et al., 2012), and to apply that model along with new photometric observations to determine the satellite’s sidereal rotational period with an accuracy that was previously unachievable. A new technique for determination of the spin-axis orientation during each passage of the satellite over an observation site was developed. The secular slowdown of the satellite’s spin rate (Рsid = 1.4858EXP(0.000041099T), where Т is measured in days counted from the date of the satellite launch) and its variations correlating with the average duration of the satellite orbit out of the Earth’s shadow were refined. New parameters of the spin-axis precession were estimated: the period Pprec = 116.44 days, αprec = 18.0h, δprec = 87.66°, the nutation angle θ = 1.78°.
Ukrainian database and Atlas of light curves of artificial space objects
(Одеський національний університет імені І. І. Мечникова, 2017) Koshkin, Nikolay I.; Savanevych, V.; Pohorelov, A.; Shakun, Leonid S.; Zhukov, V. V.; Korobeinikova, E. A.; Strakhova, S. L.; Moskalenko, Sergiy; Kashuba, V. I.; Krasnoshchokov, A.; Кошкин, Николай Иванович; Кошкін, Микола Іванович
This paper describes the Ukrainian database of long-term photometric observations of resident space objects (RSO). For the purpose of using this database for the outer space monitoring and space situational awareness (SSA) the open internet resource has been developed. The paper shows examples of using the Atlas of light curves of RSO's for analyzing the state of rotation around the center of mass of several active and non-functioning satellites in orbit.
Using synthetic light curves of artificial satellite model to test the patterns method for determining the rotation axis orientation
(Odesa I. I. Mechnikov National University, 2024) Koshkin, Mykola I.; Shakun, Leonid S.; Korobeinikova, Olena O.; Melikyants, Seda M.; Strakhova, Svitlana L.; Kozhukhov, O. M.; Кошкін, Микола Іванович; Шакун, Леонід Сергійович; Коробейнікова, Олена Олександрівна; Мелікянц, Седа Мнацаканівна; Страхова, Світлана Леонідівна; Кожухов, О. М.
In this paper we test a new method for determining the rotation axis direction in space for various resident space objects (RSOs). This method (Koshkin et al., 2024) is based on the structural analysis of the light curves of such RSOs and the search for similar fragments, called "photometric patterns", in observations obtained from one or several observatories simultaneously or over a short period of time. The method does not require prior knowledge of the RSO shape and does not impose strict requirements on the quality of observations, and this is its main advantage. First of all, this method is certainly applicable to rapidly rotating objects of complex shape with smooth surfaces. As a result, such RSOs are capable to reflect sunlight in a specular manner, when short-term brightness flares are present in the light curves forming a unique pattern. Identical patterns are observed when the angle between the phase angle bisector (PAB) and the rotation axis reaches the same values. However, the light curves of many RSOs have a significant diffuse component in addition to the specular flares. This diffuse component depends on both the phase angle value and the orientation of the phase angle plane relative to the RSO’s plane of rotation. This paper is devoted to checking the assumption that the structure and shape of diffuse-specular patterns will remain similar to themselves within certain limits of variation of the value of these two angles at moments of equality of the PABs’ latitude. The analysis is based on simulation using synthetic light curves of the RSO model, observed from several points on the Earth's surface.
Кластерный анализ базы данных параметров орбит ИСЗ
(Астропринт, 2011) Шакун, Л. С.; Кошкин, Николай Иванович; Shakun, Leonid S.; Koshkin, Nikolay I.; Кошкін, Микола Іванович
The relational base of orbital parameters of near-Earth space objects (SO) is created. For 2007 it is led correlative and cluster analysis on variations of values В* for 4.5 thousand of low-Earth orbit (LEO) objects. Clusters LEO with similar character of atmospheric drag are selected.

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