Перегляд за Автор "Romanyuk, Ya."

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  • Ескіз
    Документ
    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.
  • Ескіз
    Документ
    Simultaneous multi-site photometry of Leo Satellites to characterise their rotation states
    (Одеський національний університет імені І. І. Мечникова, 2020) Koshkin, Nikolay I.; Shakun, L.; Melikyants, S.; Korobeynikova, E.; Strakhova, S.; Bilinsky, A.; Vovchyk, Ye.; Kudak, V.; Motrunich, І.; Neubauer, I.; Kozhukhov, O.; Romanyuk, Ya.; Ryabov, A.; Terpan, S.; Dragomiretsky, V.; Golubovskaya, T.; Кошкін, Микола Іванович; Кошкин, Николай Иванович
    The photometry of space objects (SO) makes it possible to determine their state of rotation around the center of mass, orientation of the rotation axis and rotation speed in the most cost-effective manner. However, the methods for determining the attitude parameters from photometric data from a single observation site (OS) require long series of high-quality and high-frequency measurements. We propose a method for determining the orientation parameters of slowly rotating SO based on simultaneous multi-site photometry with a high temporal resolution. Preconditions for planning and building a local photometric network that can accomplish such a task have been tested via computer simulation. Synchronous observations of the unoperated spacecraft TOPEX/Poseidon were carried out. They were attended by the observatories of Odessa, Lvov and Uzhgorod universities, as well as the observation station of the State Space Agency of Ukraine in Zalistsi, Khmelnytsky region, took part. Synchronous network-based photometric observations from three OSs enable us to calculate time lags between correlated lightcurve segments and promptly determine the direction of rotation, as well as the spatial orientation of a SO’s spin axis and its angular spin rate. A local network of several distributed observation sites for synchronous monitoring of the rotation of various SO in LEO will make it possible to determine the rotation parameters of also slowly rotating objects that do not exhibit glints within their light curves.