一种适用于遥测测距信号的新型码跟踪环

遥测测距技术采用再生伪码作为上行链路信号。针对飞行器现有码跟踪环结构复杂、低信噪比条件下环路跟踪性能差的问题,提出了一种新的基于锁相环的码跟踪环结构,推导了环路的信号处理流程。该结构降低了环路实现的复杂度,改善了低信噪比条件下的相位测量精度,仿真进一步验证了方法的有效性和稳定性,较现有方法在信噪比为-10 dB时能提高1.5×10－3个码片的精度,适合遥测测距技术。     

Frequency recovery techniques for TM/TC satellite modem in critical scenarios

Reliability and effectiveness are essential features of satellite transceivers for telemetry and telecommand applications. Modem performance has a strong impact on the success of a satellite mission, in particular, during critical scenarios as the early operation phase, the disposal of a satellite at the end of its life, or the deep‐space missions. In these specific mission critical scenarios, fast and correct data reception is even more important than high channel capacity. An unknown and fast variable channel condition, which can be caused by uncertain spacecraft attitude and large Doppler shift with respect to the data rate, requires efficient and innovative receiver architecture. This paper introduces a complete digital implementation of a transceiver for TM/TC application in low Earth orbit mission that is perfectly compliant with aforementioned requirements. Particular attention is dedicated to the definition and selection of the most appropriate frequency recovery technique; 2 open‐loop techniques that are derived from ML optimal estimator are presented and compared. Additionally, the performance of the proposed receiver is extensively studied and compared with an incoherent technique that is based on the double differential PSK modulation and is known to be suitable for sat‐com in critical scenarios.     

基于公钥基础设施的Hadoop安全机制设计

为了满足运载火箭遥测系统集成验证的测试需求,同时提升测试设备的通用性,降低测试设备的研制成本,本文采用面向信号的设计思想,设计了一种简洁高效的遥测系统自动化测试平台。该测试平台基于PXI总线开发,通过采取多路复用开关与输入输出模块相结合的设计思路,可实现多参数的巡检测试及同时测试,使测试平台具有较好的通用性和灵活性,在硬件设备不做更改的前提下可适用于多型运载火箭的测试需求,同时研制成本大幅降低;通过接收解析箭上遥测数据,测试过程无需人工干预,实现了自动化测试与自动化判读。通过试验验证,该测试平台工作稳定,能较好的满足多型运载火箭遥测系统集成验证测试需求,同时该平台的设计方法为同类测试系统的设计提供了一种思路。     

Novel statistical method for data drift detection in satellite telemetry

Autonomy is becoming a prime requirement for satellite mission control operations. Data-driven methods like Machine Learning models are playing a key role in bringing in autonomy. Health keeping data from satellite telemetry is a key ingredient in these data-driven methods. In real-world satellite operations, the health-keeping telemetry data gradually drifts due to adverse space weather effects and wear and tear of electronic and mechanical components. The key question that arises is how to detect and quantify the data drift which is generally a gradual phenomenon. This paper discusses a novel statistical method for detecting data drift occurring in satellite telemetry. For the purpose of experimental work in this paper, an actual telemetry data set of the BUS CURRENT sensor which is part of the Electrical Power System of a Low Earth Orbit Satellite was considered. Data drift detection test was carried out using this sensor data using the developed novel statistical method and with Kolmogorov Smirnov test which is a probabilistic method. Both results are analysed and compared. Thereafter novel statical method was used to check its efficacy using a synthetic data set with induced drift.     

飞行试验颤振数据实时监控系统

颤振试飞是＂I类风险＂试飞科目,试飞风险巨大。而原型机和涉及到结构及外型重大更改的改型机都必须进行颤振科目试飞。因此要制定严格的保障措施,高效、准确的监控保证。由于颤振数据的高采样率,为保障整个监控系统的性能,采用单独的服务器与独立的局域网,并在颤振服务器上加装A/D转换器,结果该颤振数据实时监控系统可按512点/s的采样率无丢点采样存盘,条图仪均匀输出。通过前期原理论证及后期使用证明该系统能满足高采样率下颤振数据的实时监控要求,而且它解决了在UDP传输协议的网络中高采样数据条图仪输出的时间均匀性问题。     

基于时间序列的航天器遥测数据预测算法

在航天器遥测数据预测领域,基于时间序列的预测方法有着广阔的应用前景;时间序列有一明显的特性就是记忆性,记忆性是指时间数列中的任一观测值的表现皆受到过去观测值影响;它的基本思想是根据观测数据的特点为数据建立尽可能合理的统计模型,利用模型的统计特性解释数据的统计规律,以期达到预报的目的;提出了采用模式识别和参数估计的方法,结合航天器遥测动态数据,建立关于航天器遥测数据的时序预测模型,对航天器遥测数据趋势进行检测和预报。     

基于帧格式的调频遥测信号检测方法分析

针对航天器测控特点,低信噪比信号检测是实现航天测控系统目标快速捕获的关键技术。为了解决调频遥测信号低信噪比检测难题,介绍了采用正交矢量瞬时测频方法的调频遥测信号解调方法,分析了调频遥测信号帧格式,在此基础上提出了基于帧格式的调频遥测信号匹配滤波检测法。仿真结果表明所提方法能实现在低信噪比条件下调频遥测信号的高概率检测。     

多目标综合遥测监控系统架构设计

为了满足新型飞机多机协同试飞、高机动性、超音速巡航等试飞特性,对遥测监控系统提出的高采样参数多、实时处理数据量大、遥测资源协同工作能力强的需求;采用遥测天线远程控制技术,虚拟局域网技术,网络组播通信方式,对遥测监控系统结构进行设计和规划;实现遥测监控四目标、遥测监控资源集中控制、统筹利用等功能。提出了满足新型飞机安全监控需求的多目标综合遥测监控系统设计思想,并验证了可行性、技术先进性和使用价值,达到提高试飞安全性和实时数据处理效率的目的。     

民机试飞空地一体化综合监控网络系统技术研究

以ARJ21适航审定试飞工程为背景,针对民机适航审定试飞的需求和测试特点,从优化系统架构和平衡系统性能等方面,对机载和地面各系统关键技术进行了分析。解决了新型多路网络化数据采集对机载和地面综合监控带来的一系列问题。提出了一套适合民机适航审定试飞的空地一体化综合监控网络系统解决方案。经过飞行试验证明,完全能够满足适航审定试飞空地一体化综合监控的要求,为今后大型飞机试飞测试及综合监控方法的研究提供了借鉴。     

基于PCM-FM体制下遥测作用距离研究

为了实现靶场试验数据的有效采集、遥测接收和发射系统的设计选择、遥测地面站合理布置等目的,在PCM-FM遥测体制下,采用靶场试验中典型的频点和码速率以及给出相应的遥测地面站的情况下,对遥测作用距离和遥测接收系统门限进行详细的分析和计算。同时对影响遥测作用距离的几个关键因素进行分析讨论,获得了对同一遥测发射和接收系统下,不同码速率的系统接收门限和遥测作用距离的计算结果。遥测作用距离的研究对遥测系统设计中码速率选择、遥测发射和接收机的研制具有重要的指导意义。