卫星地面测试通用MTP软件设计与实现

为了满足卫星测试软件平台化和面向多型号的需求,提高卫星测试软件的灵活性和可扩展性,提出了一种基于插件的主测试处理机MTP(Master Test Processor)通用框架,介绍了该框架的结构及提供的各种服务,定义了插件的标准接口,提供了插件和MTP运行时(MTP Runtime)之间交互的方法.实践证明,基于此框架开发的MTP测试软件可用于多种型号卫星的测试,缩短了软件开发周期,极大地提高了卫星地面综合测试系统的测试能力.     

利用扭秤进行空间干涉仪的地面测试技术

空间干涉仪作为下一代重力卫星、空间引力波探测计划的核心部件之一,其灵敏度远高于目前电容式读出的惯性传感器。但由于空间干涉仪涉及技术细节过多,需在地面研制阶段接受大量测试,而低频测试频段以及极低噪声环境的苛刻要求成为当前地面测试阶段的最大挑战之一。该文介绍以悬挂扭秤为核心技术的地面测试平台,其在竖直方向可由悬丝平衡地球所带来的引力影响,而在水平方向可模拟准自由落体状态。选用经过特殊设计而成的悬挂扭秤作为测试对象,可将地面测试中的主要噪声——地面振动噪声降低3~4个量级,使得加速度噪声在观测频段可低至10−13 m·s^−2·Hz^−1/2@mHz,已达到目前该频段的测量极限,该技术也是目前国际上公认的空间干涉仪地面研制阶段的最佳测试平台之一。     

基于柔性测试网络的在轨测试平台设计

为了满足卫星地面站和测试站相距数百公里部署场景下进行地面链路指标测试、卫星在轨测试、任务阶段频谱监视等多任务在轨测试需求,对传统在轨测试系统进行了设计改进,提出了一种基于柔性测试网络的测试系统构建思路.提出了利用等幅多载波群时延测量方法进行异地群时延测量;设计了光传输链路替代传统波导的微波信号传输链路,并进行了可行性试验;构建了可自动切换满足各阶段各类别测试项目并行测试的柔性测试网络;测试软件的服务端采用面向服务的软件架构,测试客户端采用平台加插件架构,实现了测试系统设备可定义、任务可并发、流程可定制的能力.     

大型飞机地面空调现场测试方法的探讨

大型飞机地面空调往往体积很大,难以实现试验室内的性能测试。本文主要提出一种现场测试方法,供业内人士参考。     

系统工程方法在风云三号极轨气象卫星地面应用系统工程中的应用

简要介绍了基于需求分析的风云三号（FY-3）卫星观测能力设计,并阐述了卫星地面应用系统如何利用系统工程方法进行地面系统顶层设计,统筹FY-3卫星和地面系统工程需求,合理布局地面接收站,科学划分地面系统各功能单元的任务,实现建成后的地面应用系统整体能力最大化。     

基于性能参数检测与外部测试的测试性探讨

测试性是现代大型复杂工程设备设计的一项重要内容,测试性设计是改善其系统测试性能和故障诊断能力的有效途径.测试性的设计思想和诊断策略多是建立在机内测试(BIT)和故障率分析的基础之上的,针对以机械系统为主设备的测试性研究才刚刚起步.本文在分析电子设备和以机械系统为主设备各自结构特点的基础上,指出以往的测试性理论和方法不适用于以机械系统为主的设备,提出了基于性能参数检测与外部测试的测试性研究思想,确立了通过固有测试性设计、以外部测试为主进行故障诊断等方法来改善系统测试性的策略,找出了适用于机械系统的主要测试性表征参量.     

基于新型H形DGS超宽带低通滤波器设计

滤波器是微波电路的重要元件,在实际中有着广泛的应用.对传统的H形缺陷地面结构进行了改进,提出了新型的H形缺陷地面结构(H-shaped DGS),研究了新结构的传输特性,利用所提出的新型结构设计了一个超宽带低通滤波器,并对其进行仿真与测试,仿真结果与实验结果吻合较好.测试结果表明:所设计的低通滤波器的3dB通带截止频率...     

固体火箭发动机地面点火试验高精度测试系统的设计与开发

高精度测试系统是固体火箭发动机地面点火试验部分的核心组成系统,测试数据获得的完整性与准确性是固体火箭发动机地面试车时是否能够真实反映其性能指标的重要条件之一.高精度测试系统是针对推力、压强、应变、温度等物理量进行测量的数据采集系统,满足多通道、快速和高精度测试.该系统是基于PXI+SCXI总线的虚拟仪器系统,使用软件将计算机与功能化硬件系统结合起来,从而完成对被测试量的采集、分析、显示、数据存储等功能.通过功能测试和性能测试验证了系统满足固体火箭发动机地面点火试验测试系统的技术要求.     

离子电推进系统在高通量卫星上的应用测试及飞行试验

亚太6D卫星是由亚太卫星宽带通信(深圳)有限公司(亚太星通)采购,与香港亚太通信卫星有限公司(亚太公司)共同监造的一颗地球静止轨道宽带通信卫星,是中国首个开展电推进技术商业化应用的卫星。卫星采用了基于兰州空间技术物理研究所LIPS-200型离子推力器的电推进系统,电推进系统在轨执行卫星15年南北位置保持任务。由于性能验证必须具备真空环境,因此将电推进系统搭载在卫星上,采用一系列测试手段和方法,确认电推进系统与其他系统之间工作的兼容性。重点介绍了卫星电推进设计,集成性能测试、功能兼容联试、真空点火测试、真空电磁兼容测试等。对电推进初步飞行结果的分析表明,电推进系统与卫星全方位兼容。卫星发射入轨后,将对电推进系统的推力、功率等进行测试评估,确认电推进工作状态满足南北位置保持任务需求。     

卫星地面测试通用MTP软件设计与实现

为了满足卫星测试软件平台化和面向多型号的需求,提高卫星测试软件的灵活性和可扩展性,提出了一种基于插件的主测试处理机MTP（Master Test Processor）通用框架,介绍了该框架的结构及提供的各种服务,定义了插件的标准接口,提供了插件和MTP运行时（MTP Runtime）之间交互的方法。实践证明,基于此框架开发的MTP测试软件可用于多种型号卫星的测试,缩短了软件开发周期,极大地提高了卫星地面综合测试系统的测试能力。     

BER performance analysis of compound chaotic sequence (CCS)-based NR-DCSK system under multipath fading channel

This paper presents the performance analysis of compound chaotic sequence (CCS)-based noise reduction differential chaos shift keying (NR-DCSK) system under multipath Rayleigh fading channel conditions. The special characteristics of chaotic sequences are their deterministic randomness behaviour that adds security and multipath immunity to the data when used as a carrier in communication systems. In this paper, the chaotic sequences are generated by combining the outputs of chaotic maps, such as logistic map, Chebyshev map, Bernoulli shift map, tent map, etc., leading to new complex sequences known as CCSs. This sequence possesses more randomness, overcomes severe interference levels encountered during transmission and provides higher multipath immunity compared with those of pseudo-noise (PN) codes. Since NR-DCSK is a spread spectrum technique, its performance in wireless multipath fading channels has important considerations. The CCS is used as a carrier in NR-DCSK systems, which leads to improved bit error rate (BER) performance. Comparisons of simulation results to theoretical BER expressions of additive white Gaussian noise (AWGN) and Rayleigh fading channels have been carried out to test the efficiency of the proposed CCS-based NR-DCSK system.     

某高轨星载数传天线的振动分析

为了确保天线系统在发射阶段和入轨工作阶段的安全，对研制的某月球轨道小型星载数传天线进行了振动分析。通过有限元建模仿真方法对该高轨星载天线在发射阶段和入轨工作阶段的振动性能进行了分析和计算，并以此为根据对天线系统结构进行优化设计。进而，通过振动试验对天线系统进行了真实振动环境条件下的测试，结果表明天线系统结构安全。振动试验后对天线电气性能进行了复测，测试结果表明其电气性能稳定，由此验证了天线系统的可靠性和有限元分析的可信性。目前，该数传天线已随星发射并入轨运行，其各项性能指标稳定，工作状态良好。研究结果对提高相关星载天线的振动安全性具有一定的参考作用。     

基于虚拟仪器技术的小卫星测试平台

小卫星以其小型化、微型化、轻型化、高密度、软件化和智能化的特点赢得越来越多的用户．小卫星测试系统应具有灵活、方便、低成本、短开发周期等特点．基于虚拟仪器技术的测试系统可配置性好,重复利用率高,又可利用最新的计算机软硬件技术．本文介绍一种基于虚拟仪器技术的小卫星自动测试平台．     

In silico screening of carbon-capture materials

One of the main bottlenecks to deploying large-scale carbon dioxide capture and storage (CCS) in power plants is the energy required to separate the CO(2) from flue gas. For example, near-term CCS technology applied to coal-fired power plants is projected to reduce the net output of the plant by some 30% and to increase the cost of electricity by 60-80%. Developing capture materials and processes that reduce the parasitic energy imposed by CCS is therefore an important area of research. We have developed a computational approach to rank adsorbents for their performance in CCS. Using this analysis, we have screened hundreds of thousands of zeolite and zeolitic imidazolate framework structures and identified many different structures that have the potential to reduce the parasitic energy of CCS by 30-40% compared with near-term technologies.     

RNSS射频基带一体化芯片测试方法研究

随着卫星导航产业的快速发展,导航芯片成为民用卫星导航应用的核心竞争力。拥有诸多优势的射频基带一体化芯片是导航芯片发展的主流方向之一,本文依托某应用推广项目,对国产的该类芯片进行测试验证,通过不同模态下对其定位精度和跟踪灵敏度的考核,验证了芯片的基本功能,对该类芯片的测试方法进行了初步研究。     

空间多光谱成像的旋转滤光轮机构动力学试验研究

分时获取不同谱段的光谱信息是空间多光谱成像的前提。为了满足卫星相机多光谱成像中的光谱细分要求,设计了一种高精度、高稳定性分光器装置,通过周边安装的步进电机驱动大尺寸角接触球轴承实现滤光片频繁的切入切出运动。采用数值模型与模态试验方法验证机构的动力学特性,根据正弦扫频及随机振动试验分析滤光轮机构在卫星发射阶段的有效性,一种地面微振动试验用以描述滤光轮机构的在轨稳定性。数值分析与试验结果表明,旋转滤光轮机构满足发射安全性与在轨稳定性需求。这类周边驱动大尺寸薄壁轴承的新型旋转滤光轮为大口径卫星相机的空间应用提供了一种新途径。     

The telecommand system

The telecommand system plays an important role in the success of any satellite mission. This paper provides insights into the design, development and evolution of theAryabhata telecommand system. The paper includes detailed specifications and performance of both the ground and onboard segments of the telecommand system.     

New design of cylindrical capacitive sensor for on-line precisioncontrol of AMB spindle

A new cylindrical capacitive sensor (CCS) design for the displacement measurement of precision active magnetic bearing (AMB) spindle is presented in this paper. This research is motivated by the problem that the existing 4-segment CCS is still sensitive to the third harmonic component of the geometric errors of a rotor. The procedure of designing a new CCS starts from the modeling and error analysis of CCS. The angular size of CCS is set up as a design parameter, and a new configuration, i.e., 8-segment CCS, is introduced to possess an arbitrary angular size. The optimum sensor geometry to minimize the effects of geometric errors is determined through the minimum norm approach. Experimental results with test rotors have confirmed the improvement in geometric error suppression     

On measurement noise in the European TWSTFT network

Two-way satellite time and frequency transfer (TWSTFT) using geostationary telecommunication satellites is widely used in the timing community today and has also been chosen as the primary means to effect synchronization of elements of the ground segment of the European satellite navigation system Galileo. We investigated the link performance in a multistation network based on operational parameters such as the number of simultaneously transmitting stations, transmit and receive power, and chip rates of the pseudorandom noise modulation of the transmitted signals. Our work revealed that TWSTFT through a "quiet" transponder channel (2 stations transmitting only) leads to a measurement noise, expressed by the 1 pps jitter, reduced by a factor of 1.4 compared with a busy transponder carrying signals of 12 stations. The frequency transfer capability expressed by the Allan deviation is reduced at short averaging times by the same amount. At averaging times of >1 d, no such reduction could be observed, which points to the fact that other noise sources dominate at such averaging times. We also found that higher transmit power increases the carrier-to-noise density ratio at the receive station and thus entails lower jitter but causes interference with other station's signals. In addition, the use of lower chip rates, which could be accommodated by a reduced assigned bandwidth on the satellite transponder, is not recommended. The 1 pps jitter would go up by a factor of 2.5 when going from 2.5 MCh/s to 1 MCh/s. The 2 Galileo precise timing facilities (PTFs) can be included in the currently operated network of 12 stations in Europe and all requirements on the TWSTFT performance can be met, provided that suitable ground equipment will be installed in the Galileo ground segment.     

Far-Field Pattern Measurement of an Onboard Laser Transmitter by Use of a Space-to-Ground Optical Link

The far-field pattern of an onboard laser transmitter was measured with a transatmospheric optical link with a distance of ~33,000 km between the satellite and the optical ground station. The far-field pattern was acquired with a new method used to analyze statistically downlink irradiance data obtained at the ground station. The statistical tracking and pointing characteristics of the transmitter were taken into account in estimating downlink irradiance, assuming that there were no atmospheric scintillation effects. The peak directive gain of the downlink laser beam was 104.3 dB. The beam width (full width at half-maximum) was 28.5 x 17.5murad. These results were consistent with the results froma laboratory test undertaken before launch of the satellite.