基于对比序列重构的卫星遥测数据异常检测方法

基于遥测数据的异常检测是卫星在轨运维管理的关键技术。 但现有方法大多仅采用正常样本建立模型,异常检测结果 对判读阈值敏感、虚警率较高。 对此本文提出基于对比序列重构的卫星遥测数据异常检测方法,充分利用有限异常先验增强异 常检测中正常、异常样本差异。 先基于变分自编码器提取遥测数据时序演化特征,引入对比学习方法建立对异常、正常数据差 异化输出的编码器,再用大量正常数据进一步训练整个模型实现对正常数据的精准重构形成对异常数据敏感的时序数据重构 模型,再基于核密度估计方法学习异常判读阈值进一步提升异常检出率。 在真实卫星遥测数据上验证表明所提方法能有效降 低异常检测的虚警率(均低于 0. 002)并保持较高的检出率具备良好的实际应用水平。     

基于太阳能光伏的无线户外环境监测系统设计

设计了一种采用太阳能供电模式的无线户外环境监测系统;该系统由终端节点,ZigBee-GSM网关和上位机数据存储中心组成,集成ZigBee和GSM无线通信,根据用户发送的短信指令控制终端节点数据采集的通断,同时用户发送短信指令远程查询户外环境的重要信息;针对户外环境因子的特点,选用工业级、灵敏度高的传感器,对户外不同位置的PM2.5浓度和紫外线指数进行测量,测量结果既可在上位机实时显示和存储,也可以由ZigBee-GSM网关通过SIM900A模块发送至移动终端;户外测试结果表明,该系统运行稳定,数据传输可靠,能快速地实现远程遥测功能,为户外环境远程监测提供了一种技术手段。     

基于IEC 61850的电力远动通信建模方法

为了保障不同厂商设备之间实现互操作,文中研究了IEC 61850标准的公共数据类、数据类、数据集和报告等模型,提出基于IEC 61850标准的电力远动通信建模方法,建立电力远动通信的逻辑设备、逻辑节点,以及信息交换服务模型.在模型中,控制中心作为IEC 61850客户端,变电站内的智能电子设备(IED)或代理/网关充当IEC 61850服务器,通过IEC 61850服务实现控制中心与变电站之间的远动通信.关联模型被用来建立IEC 61850客户机与服务器之间的双边应用关联,数据模型被用于遥测与遥信量的读取,数据集和报告模型被用来实现遥测、遥信数据的召唤和循环上传,以及主动变位与事件顺序记录.     

微波开关自动测试系统设计

针对当前微波开关指标测试流程复杂、测试方法自动化程度低问题,提出了一套集指标测试、数据采集和数据管理功能于一体的自动化测试系统;该系统基于微波开关生产及试验环节的实际使用需求,通过软件平台实现对通用测量仪器及遥控遥测设备、射频开关矩阵等设备的自动化控制,单次可满足最多16个微波开关的同步测试,可实现同轴型和波导型两种开关类型总计18种指标参数的测试和试验数据管理,达到了测试效率和试验质量的双提升     

High degree of individual repeatability found in the annual migrations of walleye (Sander vitreus) in eastern Lake Ontario

Adult walleye (Sander vitreus) conduct annual migrations from riverine spawning sites in the Bay of Quinte into the eastern basin of Lake Ontario to forage. Although fidelity to spawning river is quite high for these fish across the Laurentian Great Lakes, very little is known about the repeatability of site selection along the entirety of their annual migration. This study used multiple years of acoustic telemetry (2018–2020) to assess the within-individual repeatability of the timing associated with major migratory events (spawning river entry and departure, main lake entry and departure), as well as the average monthly spatial distribution of individuals throughout the year. Fine-scale sequence analysis was used to combine these two metrics to assess the within and among individual sequence dissimilarity in the population. Within-individual repeatability was high across most timing and spatial measures, and the sequence dissimilarity within individual sequences was significantly less than that among individuals. Sex and size were not significantly related to sequence dissimilarity, while individuals from the Trent River displayed more dissimilarity than those from the Napanee River. The high level of within-individual annual repeatability in migrations was demonstrated not only during spawning activity, but at a daily level throughout the entire year. This research shows that walleye possess the ability to orient themselves and navigate across long distances in a highly repeatable manner at all times of the year. Future work will be required to better understand the underlying mechanisms and drivers behind these abilities.     

Assessing migratory bottlenecks and escapement of silver eel (Anguilla anguilla) in the highly urbanized North Sea Canal basin,the Netherlands

Habitat fragmentation and migration barriers have attributed to the decline of European eel (Anguilla anguilla). The migration of silver eels through pumping stations, ship locks, and migration facilities within the North Sea Canal basin using acoustic telemetry and overall escapement by mark–recapture was studied. A network of 61 acoustic receivers and three PIT-tag stations was built, and 305 silver eels were tagged with acoustic transmitters and 3923 with PIT-tags. Of all the silver eels that were detected, 55% passed barriers between the polders and the canal and 46% also passed the barrier complex at IJmuiden to sea, mainly via the ship locks. Overall, silver eel escapement to the North Sea per year averaged 81,629 silver eels and 14.3% suffered mortality in the pumping station at IJmuiden. Migration speed was lower for silver eels that initiated their migration upstream compared with silver eels further downstream, higher for silver eels passing barriers later in the migration period, and highest at sea. This study of silver eel movement and escapement in the North Sea canal basin indicated several bottlenecks. Passage success along barriers varied strongly between sites and types of barriers. While at two smaller locations, silver eels migrated through the pedal valves in the ship lock gates, a small passage facility and the pedal valves in a ship lock at complex IJmuiden did not enhance silver eel migration. The barriers and unnatural canal system caused additional delay during silver eel migrations. Mitigation measures for management could include installing fish-friendly pumps, using pumping stations only during the day, and in addition opening ship locks and pedal valves at the beginning of the night.     

遥测数据处理系统UML建模与实现

遥测数据处理系统用于各项武器系统试验,完成遥测缓变和速变参数处理任务.为克服旧系统弊端,构建高效可靠的系统软件,采用面向对象的分析设计方法.在详细分析系统功能和需求基础上,利用建模语言(UML)在建模表述上的标准性和通用性,给出系统的用例模型、静态结构模型和动态行为模型.并以可视化图形界面展现系统功能结构,描述系统对象之间信息交互以及系统对动态事件的处理流程,从而使系统软件设计和开发工作更加规范合理,软件开发周期更短.最后完成了系统构建并成功应用于实际任务中,应用结果充分验证了模型的可行性和有效性.     

数字电传系统的研制及其在水情遥测中的应用

研制了基于８９Ｃ５２和ＶＤ５０２６／５０２７的数字电传系统，并将其应用于水情、雨量的遥测中，本文主要介绍此系统的设计思想和框架结构，并介绍了我们在硬件设计时为提高系统可靠性而采取的措施。     

丹江口水库水情测报系统改造及应用

丹江口水库水情测报系统已经建设多年,面临设备老化,中心站不稳定,特别是存在需要整合多个厂家遥测设备及采用不同信道进行通信传输等问题,为提高测报系统的安全性、稳定性和集成性,进行多信道多协议遥测系统设计及改造,应用效果表明系统运行稳定可靠、监视信息丰富,并具有较强的可扩充性,运维便利,为丹江口水库调度提供更有力的支撑。     

Novel insights gained from tagging walleye (Sander vitreus) with pop-off data storage tags and acoustic transmitters in Lake Ontario

Improvements in electronic tagging techniques provide new opportunities to gain insights into fish habitat selection and behaviours that have been difficult to capture using traditional assessment methods. However, data from acoustic telemetry studies in large freshwater systems may bias our understanding of fish habitat use and behaviour because of the typically low sampling frequency of transmitters as well as the limited spatial coverage and distribution of receivers in a waterbody. This study combined acoustic transmitters and pop-off data storage tags (pDSTs) on individual walleye in Lake Ontario to gain a better understanding of the feasibility and utility of double tagging a large nearshore freshwater fish. High frequency pDST data (every 2 s) revealed a novel diving behaviour by walleye which made repeated rapid dives beyond their standard daily depth range. Comparison of data from the two tag types showed that in this large freshwater system with low overall receiver coverage (∼4%), mean monthly and daily depth and temperature occupancy of walleye were similar, although many of the extreme values observed in the pDST data were not observed in the acoustic data. The accuracy of daily vertical distance travelled by walleye and summertime diving parameters was dependent on sampling frequency and only the pDST logging on a 2 s interval was able to provide reliable results. The results of this study show that novel insights can be gained, for fish large enough to handle the burden of multiples tags, ranging from spatial ecology to diving behaviours.