ОБЕСПЕЧЕНИЕ ЧУВСТВИТЕЛЬНОСТИ И РАДИОМЕТРИЧЕСКОГО РАЗРЕШЕНИЯ РСА Х-ДИАПАЗОНА НА БАЗЕ МАЛЫХ КОСМИЧЕСКИХ АППАРАТОВ
Creators: name: Храмов Константин Константинович
name: Костров Виктор Васильевич
Publisher: name: Радиотехнические и телекоммуникационные системы
Year: 2022
Subjects: радиолокатор с синтезированием апертуры
РСА
малый космический аппарат
радиометрическая чувствительность
радиометрическое разрешение
synthetic aperture radar
radar
small spacecraft
radiometric sensitivity
radiometric resolution

description: В статье рассмотрены вопросы оценки и обеспечения требуемых значений радиометрической чувствительности и радиометрического разрешения радиолокаторов с синтезированием апертуры (РСА) космического базирования при их работе на базе малых космических аппаратов. Приведены необходимые ма-тематические выкладки и выполнен расчёт указанных величин для РСА Х-диапазона, работающих в маршрутном режиме обзора при максимальном разрешении. Проведён анализ влияния основных технических характеристик и параметров космических РСА на чувствительность и радиометрическое разрешение, оце-нены достижимые значения последних.
description: The article examines issues of evaluating and ensuring the required values of radiometric sensitivity and radio-metric resolution of space-based synthetic aperture radar (SAR). These parameters during SAR operation based on small-size spacecrafts are critical, since the resource of power supply system is limited. There arises a tech-nical contradiction between radiometric properties and other SAR parameters. The article’s purpose is to esti-mate attainable radiometric sensitivity and radiometric resolution of space-based SAR when operating within limitation in emitting power and antenna system size. That’s why the article’s matter is relevant. The spacecraft is assumed to have a circular orbit and 550...650 km altitude. A normal lateral visibility (en-route mode) is under consideration, which is performed by space-based X-range SAR. The necessary mathematical manipulations are presented and SAR sensitivity calculations are made (noise equivalent of the specific effective area of dispersion) and calculations of radiometric sensitivity at maximum spatial resolution were made as well. The effect of major technical properties and parameters of space-based SAR was analyzed in respect to sensitivity and radiometric resolution and available values of the latter were estimated. Particular emphasis is made on the research of the effect of antenna’s effective aperture area on radiometric sensitivity. The obtained analysis results and functional dependencies enable to define boundaries of potentially available radiometric sensitivity considering limitations in transmitter power and antenna dimensions. It is demonstrated that if non-coherent integration is applied to ensure the required radiometric resolution value, then there is an exchange of spatial resolution for radiometric one, and the required number of integrations depends on the primary resolution. Such an exchange is made in current SAR if high-performance processing systems are available and, as a rule, through inter-element integra-tion along the area of the object under observation.