The PoGOLite star tracker system
The PoGOLite star tracker system
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PoGOLite星追踪系统
DOI：
10.1109/nssmic.2008.4774604
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
C. Bettolo
中科院分区：
文献类型：
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作者：
C. Bettolo
PoGOLite是一个球载实验，将通过应用阱型phoswich探测器技术研究25 keV-80 keV能量范围内天体物理目标的偏振软伽马射线发射[1]。偏振伽马射线预计来自各种各样的来源，包括旋转动力的恒星，吸积黑洞和中子星，以及喷流主导的活动星系。极化测量提供了一个强有力的探测伽玛射线发射机制和周围的磁场和辐射场的分布源。使用康普顿散射和光电吸收在217个塑料反射器的阵列中确定偏振。PoGOLite偏振计的视场为2.4° x 2.4°，必须与天空中5% FOV范围内的目标保持对准，以确保200 mCrab光源的最小可检测偏振MDP=10%。这种对准可以通过不同的姿态传感器来实现：差分全球定位系统（DGPS）、两个星星跟踪器和陀螺仪。最精确的传感器是星星跟踪器，这是本文的重点。已经进行了初步研究[2]和校准，为自主星星跟踪装置铺平了道路，该装置将与其他姿态控制装置一起重建指向解决方案。
PoGOLite is a balloon-borne experiment which will study polarised soft gamma-ray emission from astrophysical targets in the 25keV – 80keV energy range by applying well-type phoswich detector technology [1]. Polarised gamma-rays are expected from a wide variety of sources including rotation-powered pulsars, accreting black holes and neutron stars, and jet-dominated active galaxies. Polarization measurements provide a powerful probe of the gamma-ray emission mechanism and the distribution of magnetic and radiation fields around the source. The polarization is determined using Compton scattering and photoelectric absorption in an array of 217 plastic scintillators. The PoGOLite polarimeter has a field of view of 2.4° x 2.4° and must be kept aligned to objects of interest on the sky within 5% of the FOV to secure a minimum detectable polarization MDP=10% for a 200 mCrab source. This alignment can be obtained by mean of different attitude sensors: a DGPS (Differential Global Positioning System), two star trackers and gyroscopes. The most accurate sensor is the star tracker which is the focus of this paper. Preliminary studies [2] and calibration have been made which pave the way to an autonomous star tracking device which together with the other attitude control devices will reconstruct the pointing solution.