共查询到18条相似文献,搜索用时 140 毫秒
1.
透视宇宙的眼睛——“硬X射线调制望远镜” 总被引:1,自引:0,他引:1
中国“硬X射线调制望远镜”(Hard X-ray Modulation Telescope,简称HXMT)天文卫星将是国际上已知计划中唯一一台既可以实现宽波段、高灵敏度X射线巡天成像,又能够研究黑洞、中子星等高能天体的短时标光变和宽波段能谱的空间X射线天文观测设备。作为我国第1颗天文卫星,HXMT已被明确列入国家《“十一五”空间科学发展规划》和《航天发展“十一五”规划》。HXMT上天后,不仅将使我国的高能天体物理观测研究达到国际先进水平,还可为提升我国在深空探测等方面的能力作出重要贡献。 相似文献
2.
HXMT卫星的空间硬X射线巡天和定点观测计划切换频繁,需要对卫星有效载荷在轨状态进行实时监测和判别.目前采用的是地面监测人员根据总结的规则进行人工监测的方式,虽然执行方便,可解释性强,但人力消耗较大,且对规则之外的情况无法灵活处理.本文利用HXMT卫星的实时遥测数据,提出一种基于LightGBM机器学习模型的在轨运行模式监测算法,将监测工作规约为多分类问题,并构建判别模型,对卫星在轨运行模式进行判断.在保障判别准确率的前提下,算法模型构建迅速,具有很高的实用性.基于真实遥测数据的试验表明,模型的判别准确率达到99.9%,满足在轨运行模式监测要求,可为HXMT卫星的运行监控任务提供参考依据. 相似文献
3.
HXMT的空间环境本底计算 总被引:1,自引:0,他引:1
硬X射线调制望远镜(HXMT)是一颗宽波段X射线(1~250 keV)天文卫星,其核心载荷高能X射线望远镜(HE)工作于硬X射线能区(20~250 keV),致力于实现硬X射线的高灵敏度巡天观测,描绘硬X射线天图,并对特殊天体作高灵敏度定点观测.为了获得高灵敏度,必须有效地抑制本底.本底主要是由轨道环境中的粒子(γ射线、质子、电子、中子)与探测器相互作用产生的.本文结合大量的描述近地空间本底的文献和最新的实测数据,整理出一套自洽的近地空间本底粒子的数据和公式,便于应用.并通过Geant 4软件模拟计算给出了HXMT的本底及本底随时间和轨道的变化. 相似文献
4.
5.
硬X射线调制望远镜(Hard X-ray Modulation Telescope,HXMT)的最重要的工作模式是扫描观测,包括巡天扫描观测和小天区深度扫描观测. HXMT的标准成像需要被观测天区完整的二维扫描观测数据,而同时利用HXMT的观测数据中包含的空间调制信息和旋转调制信息,快视成像可以在只有一维扫描的情况下获得被观测天区的较粗略的流强分布,从而可以在卫星的视场扫过一块天区后很快给出被观测天区的尽可能多的信息.本文详细介绍了快视成像的过程,并通过模拟计算给出了巡天扫描观测快视成像的灵敏度、定位精度和角分辨能力的分布.快视成像能提高HXMT发现暂现源的灵敏度,及时发现并定位出现在HXMT视场中的高能爆发现象,减少较强的暂现源和爆发对标准成像干扰将是标准成像的重要补充. 相似文献
6.
7.
正"慧眼"硬X射线调制望远镜(HXMT)是我国自主研制的第一个X射线空间望远镜。该空间望远镜于2017年6月15日在酒泉卫星发射场采用长征-4B运载火箭发射升空,并已成功获得首批数据。1"慧眼"情况简介20世纪90年代初,中国科学院高能物理研究所(简称高能所)李惕碚和吴枚在高能天体物理数据分析中发展了直接解调方法(DDM),该方法克服了 相似文献
8.
9.
10.
11.
LU Fangjun 《空间科学学报》2014,34(5):544-546
The Hard X-ray Modulation Telescope (HXMT) is China's first astronomical satellite. It will perform a broad band (1-250keV) scan survey and do pointed observations of X-ray sources to study their spectra and multi-wavelength temporal properties. The pre-flight models of the satellites have been finished, and the flight models are in production. The expected launch date of HXMT is in late 2015. 相似文献
12.
LU Fangjun 《空间科学学报》2016,36(5):633-635
The Hard X-ray Modulation Telescope (HXMT) is China's first X-ray (1-250 keV) astronomical satellite officially approved in 2011. It will scan the Galactic plane to detect new transient sources and do pointed observations of X-ray sources to study their spectra and multiwavelength temporal properties. Now the flight model of the satellite is in the final testing stage, and the expected launch date is in late 2016. 相似文献
13.
Kaikai Cui Junhua Xiang Yulin Zhang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(6):1476-1489
This study investigates the emergency scheduling problem of ground multi-object staring imaging for a single video satellite. In the proposed mission scenario, the ground objects require a specified duration of staring imaging by the video satellite. The planning horizon is not long, i.e., it is usually shorter than one orbit period. A binary decision variable and the imaging order are used as the design variables, and the total observation revenue combined with the influence of the total attitude maneuvering time is regarded as the optimization objective. Based on the constraints of the observation time windows, satellite attitude adjustment time, and satellite maneuverability, a constraint satisfaction mission planning model is established for ground object staring imaging by a single video satellite. Further, a modified ant colony optimization algorithm with tabu lists (Tabu-ACO) is designed to solve this problem. The proposed algorithm can fully exploit the intelligence and local search ability of ACO. Based on full consideration of the mission characteristics, the design of the tabu lists can reduce the search range of ACO and improve the algorithm efficiency significantly. The simulation results show that the proposed algorithm outperforms the conventional algorithm in terms of optimization performance, and it can obtain satisfactory scheduling results for the mission planning problem. 相似文献
14.
15.
The HXMT mission concept consists of a slat-collimated hard X-ray detector assembly sensitive in 20~250 keV with a collection area of about 5000 cm2. Based on the reconstruction technique by direct demodulation developed in recent years, HXMT is mainly devoted to performing a hard X-ray all-sky imaging survey with both high sensitivity and high spatial resolution. It can also be used to make pointed observations of X-ray sources to study their spectroscopic and temporal properties in details. The main detector of HXMT consists of 18 individual cylindrical NaI(T1)/CsI(Na) phoswich modules, each with anarea of 283.5 cm2 and a field of view of 5.7°× 1.1° (FWHM). Its spatial resolution and position accuracy are 5′ and 1′ by using the direct demodulation in 1994, and in 2000 its feasibility and technical demonstration study was selected as a project under the Major State Basic Research Program of China. In October 2005, this project entered the full design phase and was listed as a candidate for the first dedicated astronomy satellite around 2010. We are now also considering secondary low energy instruments for this satellite. 相似文献
16.
敏捷光学卫星密集区域推扫成像任务规划方法 总被引:1,自引:0,他引:1
敏捷成像卫星可以实现利用三轴姿态机动所形成的推扫成像模式,同时可以在机动过程中同步成像。在敏捷卫星成像任务的基础上,建立考虑推扫成像模式的敏捷卫星任务规划模型。通过高斯投影建立球面直线扫描条带的数学生成模型,并利用Matlab现有函数进行优化解算;由于模型解算的复杂性,将整体规划问题分为两层子问题分别进行处理,在条带任务分配中,设计了适用于计算机计算的含有条带分配策略的解算算法;在上层规划中,基于推扫成像的双向扫描特性,设计了基于启发式规则的敏捷卫星任务规划算法;之后,将不可规划条带拆作孤立点目标进行处理,最后通过再合成处理完成整体规划。仿真结果表明,文章所设计的算法可以有效处理实际情况下的敏捷卫星推扫成像任务规划问题。 相似文献
17.