ЭБ Коллекция:

Autonomous Streaming Space Objects Detection Based on a Remote Optical System

Fri, 01 Jan 2021 00:00:00 GMT

Заглавие документа: Autonomous Streaming Space Objects Detection Based on a Remote Optical System Авторы: Baranova, V.S.; Saetchnikov, V.A.; Spiridonov, A.A. Аннотация: Traditional image processing techniques provide sustainable efficiency in the astrometry of deep space objects and in applied problems of determining the parameters of artificial satellite orbits. But the speed of the computing architecture and the functions of small optical systems are rapidly developing thus contribute to the use of a dynamic video stream for detecting and initializing space objects. The purpose of this paper is to automate the processing of optical measurement data during detecting space objects and numerical methods for the initial orbit determination.This article provided the implementation of a low-cost autonomous optical system for detecting of space objects with remote control elements. The basic algorithm model had developed and tested within the framework of remote control of a simplified optical system based on a Raspberry Pi 4 single-board computer with a modular camera. Under laboratory conditions, the satellite trajectory had simulated for an initial assessment of the compiled algorithmic modules of the computer vision library OpenCV.Based on the simulation results, dynamic detection of the International Space Station in real-time from the observation site with coordinates longitude 25o41′49″ East, latitude 53o52′36″ North in the interval 00:54:00-00:54:30 17.07.2021 (UTC + 03:00) had performed. The video processing result of the pass had demonstrated in the form of centroid coordinates of the International Space Station in the image plane with a timestamps interval of which is 0.2 s.This approach provides an autonomous raw data extraction of a space object for numerical methods for the initial determination of its orbit.

Base of Surface Spectral Characteristics from Photospectral Measurements on the International Space Station

Wed, 01 Jan 2020 00:00:00 GMT

Заглавие документа: Base of Surface Spectral Characteristics from Photospectral Measurements on the International Space Station Авторы: Katkovsky, L. V. Аннотация: Data and processing of images and processing of images and spectra obtained by spectrometric scientifi c equipment from the ISS in the framework of the ″Uragan″ experiment are discussed. A data base of spectral brightnesses of natural objects has been compiled from many years of measurements. Examples of its use in searching for different underlying surfaces on multispectral and hyperspectral images of the earth are given.

База спектральных характеристик отражения по данным фотоспектральной системы с борта МКС

Wed, 01 Jan 2020 00:00:00 GMT

Заглавие документа: База спектральных характеристик отражения по данным фотоспектральной системы с борта МКС Авторы: Катковский, Л.В. Аннотация: Представлены некоторые результаты съемок и обработки изображений и спектров, зарегистрированных спектрометрической научной аппаратурой с борта МКС в рамках космического эксперимента “Ураган”. Описаны созданная по результатам многолетних измерений с борта МКС с помощью фотоспектральной системы база коэффициентов спектральных яркостей природных объектов и ее использование с соответствующими примерами для поиска различных подстилающих поверхностей на мультиспектральных и гиперспектральных изображениях дистанционного зондирования Земли.

Analysis of Phonon Modes and Electron–Phonon Interaction in Quantum-Cascade Laser Heterostructures

Wed, 01 Jan 2020 00:00:00 GMT

Заглавие документа: Analysis of Phonon Modes and Electron–Phonon Interaction in Quantum-Cascade Laser Heterostructures Авторы: Afonenko, A.A.; Ushakov, D.V.; Dubinov, A.A. Аннотация: The phonon modes of quantum-cascade heterostructures based on binary and ternary semiconductor compounds are simulated. The dependences of the frequencies of the structure interface phonon modes on the wave vector in the layer plane and on the phase shift in the superlattice period are calculated. It is found that the range of variation in the quantum energy of phonon modes of the GaAs/Al_0.25Ga_0.75As structure does not exceed 2 meV. The calculated resulting interband scattering rate in the structure, taking into account the interface and confined modes, barely differs from that calculated in the bulk phonon approximation