Study of radiative characteristics of a completed partial discharge

The work is devoted to the study of the optical and electrical characteristics of a completed partial discharge burning in the presence of an electrolyte (1.5% NaCl solution). The possibility of using optical sensors that are part of smartphones such as Xiaomi for research is shown. The dependence of the radiation intensity of the completed partial discharge on the value of the ballast resistance in the discharge circuit and the material of the grounded electrode (anode) is studied. The dependence of the breakdown voltage on the size of the discharge gap is also studied. It is shown that it has a nonlinear character at a significantly lower (up to 20 times) breakdown voltage in comparison with the case of the absence of an electrolyte.

The high sensitivity accelerometer ISA during the BepiColombo spacecraft Earth flyby: data analysis, lessons learned, and expected signals for the next

<p>ISA (Italian Spring Accelerometer) is a high sensitivity, relative, mass-spring accelerometer. It flies as scientific payload on-board  the Mercury Planetary Orbiter (MPO), module of BepiColombo ESA mission to Mercury. The accelerometer is sensitive to any acceleration, greater than 2*10<sup>-8</sup> ms<sup>-2</sup>Hz<sup>-1/2</sup>, that changes  the spacecraft motion from a pure free fall: the, so called, Non Gravitational Perturbations (NGP). ISA data will be added, at Mercury, to the orbit determination estimation in order to help reconstructing the orbit and to make the MPO an a-posteriori free-fall satellite.</p> <p>After the first commissioning phase, performed in between November 2018 - August 2019, and that allowed to verify the functionality of the instrument itself, the first direct verification of the correct behaviour of the system was carried out during the BepiColombo Earth Flyby. Indeed,  the spacecraft crossed the planet Earth shadow during the flyby and the direct Solar Radiation Pressure (SRP), the main contribution of NGP accelerations, dropped suddenly, marking a clear leap (gap)  in the gathered data. The scientific team compared, on the base of the satellite surface exposition and radiative characteristics, the observed “drop” in the acceleration, once removed  the on-board disturbances and inertial accelerations due to spacecraft rotations. In the talk, other ISA data recorded during the Earth Flyby are reported and expected signals for the upcoming Venus#2 Flyby and Mercury #1 Flyby are presented.  </p>

Modelling Reflection from Real Surfaces

Modelling Reflection from Real Surfaces Alexander Basov 1, George Boos 1, Vladimir Budak 1 and Anton Grimailo 1 1 National Research University "Moscow Power Engineering Institute", Krasnokazarmennaya 17, Moscow, 111250, Russia Abstract The article is devoted to modelling the reflection of radiation from real surfaces. Most of the existing models consider only the near-surface processes, although in reality the processes occurring in the volume of the layer also have a fairly significant contribution to the final radiance. The authors propose a mathematical model that takes into account volume scattering. The model is based on the radiative transfer equation, the numerical solution of which makes it possible to find the reflection and transmission radiance factors. The paper describes the features of the implementation of the model in the case of a multilayer medium, a method is proposed that makes it possible to consider the effect of a randomly uneven surface. To validate the model, calculations of the radiance of the reflected radiation from the asphalt concrete pavement were carried out: for this, the corresponding parameters were selected that describe the optical properties of the medium. A comparison of the simulation results with the results of measuring the radiative characteristics of an asphalt concrete pavement sample was carried out, which showed that the model gives sufficiently reliable results not only qualitatively, but also quantitatively. The created model allows high-speed calculations of the radiative characteristics of various surfaces for different angles of incidence and observation, which can be used both in lighting calculations and in the formation of realistic images in computer graphics.