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GNSS空间信号法时差监测方法与结果分析 被引量:2
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作者 章洁君 陈俊平 张益泽 《测绘通报》 CSCD 北大核心 2017年第1期26-29,92,共5页
比较了3种基于GNSS空间信号进行时差监测的方法,其中,单站精密单点定位(PPP)时差监测法依赖于卫星轨道和钟差的精度,高精度PPP一般采用事后处理的方法;网解时差监测法受卫星轨道误差的影响较小,且不受卫星钟差误差的影响,因此能够用于... 比较了3种基于GNSS空间信号进行时差监测的方法,其中,单站精密单点定位(PPP)时差监测法依赖于卫星轨道和钟差的精度,高精度PPP一般采用事后处理的方法;网解时差监测法受卫星轨道误差的影响较小,且不受卫星钟差误差的影响,因此能够用于高精度时差实时监测。为分析不同方法时差监测的差异,在距离不同的时间实验室之间进行了时差试验,试验中将外接相同原子钟的两个测站的时差用于评定时差监测的精度,而相距2000 km的测站用于验证高精度实时时差监测的精度。结果表明:1实时网解与事后PPP时差监测的精度相当,达到了0.16 ns;2采用PPP方法,是否固定站坐标时差结果差异的RMS为0.04 ns;3采用实时网解的方法,对于相隔数千千米的测站实时时差监测,其与PPP后处理结果的差异约为0.14 ns。 展开更多
关键词 时差监测 空间信号法 实时网解 PPP
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基于聚类、空间分集和轨迹连续的实时定位算法 被引量:3
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作者 陈业纲 徐则同 《计算机科学》 CSCD 北大核心 2015年第8期283-287,299,共6页
针对多样本消除接收信号强度其时域浮动易造成定位的更新率下降和实时性降低的问题,首先在定位阶段利用空间分集技术,建立相邻位置信号强度的矢量队列来计算当前位置的强度;然后利用轨迹的连续性质,消除时域浮动产生的定位误差,同时通... 针对多样本消除接收信号强度其时域浮动易造成定位的更新率下降和实时性降低的问题,首先在定位阶段利用空间分集技术,建立相邻位置信号强度的矢量队列来计算当前位置的强度;然后利用轨迹的连续性质,消除时域浮动产生的定位误差,同时通过对指纹数据库进行聚类,在对目标定位时只需在较小的聚类集合中进行少量计算,无需遍历整个数据库,且计算量不随指纹数据库的增大而增加,极大地降低了计算量;最后进行了实验仿真,结果表明该算法能有效减小运算量和定位误差。 展开更多
关键词 接入点 基于位置的服务 扫描点 接收信号强度 空间信号最近邻
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基于GLONASS频间偏差的GNSS时差监测方法研究 被引量:1
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作者 孔思嘉 谢维华 《全球定位系统》 CSCD 2020年第4期21-28,共8页
为实现各导航系统的兼容与互操作,需要对各导航系统间的时间偏差进行实时监测.目前,全球卫星导航系统(GNSS)时差监测的主要方法是利用空间信号法进行GNSS时差监测.由于GLONASS系统频分多址的信号体制,导致GLONASS接收机频间偏差(IFB)的... 为实现各导航系统的兼容与互操作,需要对各导航系统间的时间偏差进行实时监测.目前,全球卫星导航系统(GNSS)时差监测的主要方法是利用空间信号法进行GNSS时差监测.由于GLONASS系统频分多址的信号体制,导致GLONASS接收机频间偏差(IFB)的存在,GLONASS IFB会影响到GNSS-GLONASS的系统时差监测.为消除这一影响,本文提出了基于GLONASS IFB估计的GNSS时差监测方法,由仿真结果可知,利用该方法可以将GPS-GLONASS时差监测精度平均提高90%以上. 展开更多
关键词 GNSS 时差监测 空间信号法 GLONASS IFB
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孤岛运行下垂逆变器二次调频方法 被引量:6
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作者 董家伟 王志新 +1 位作者 朱国忠 包俊 《电力自动化设备》 EI CSCD 北大核心 2022年第5期40-46,共7页
为消除下垂控制引起的微电网频率静差,提出一种基于积分超前补偿环节的孤岛运行的下垂逆变器二次调频方法。采用基于组件连接法的小信号状态空间分析法对系统参数进行分析和设计,实现了逆变器之间无需通信即可消除频率静差,且提高了逆... 为消除下垂控制引起的微电网频率静差,提出一种基于积分超前补偿环节的孤岛运行的下垂逆变器二次调频方法。采用基于组件连接法的小信号状态空间分析法对系统参数进行分析和设计,实现了逆变器之间无需通信即可消除频率静差,且提高了逆变器下垂系数的稳定范围和多并联逆变器系统的稳定性。在MATLAB/Simulink上对多并联逆变器系统进行仿真,验证了所提方法的有效性。 展开更多
关键词 下垂控制 二次调频 信号状态空间分析 稳定性 逆变器
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GPS/BDS-3系统时差稳定性分析
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作者 刘明玥 涂锐 +2 位作者 洪菊 苗亚格 李芳馨 《全球定位系统》 CSCD 2022年第4期55-63,共9页
不同卫星导航系统之间时差的稳定性分析对时差的建模预报及应用具有重要价值,因此基于由国际GNSS服务(IGS)中心提供的数据和产品从不同测站、不同观测量、不同时间长度三个方面对GPS和北斗三号全球卫星导航系统(BDS-3)的系统时差进行稳... 不同卫星导航系统之间时差的稳定性分析对时差的建模预报及应用具有重要价值,因此基于由国际GNSS服务(IGS)中心提供的数据和产品从不同测站、不同观测量、不同时间长度三个方面对GPS和北斗三号全球卫星导航系统(BDS-3)的系统时差进行稳定性分析.结果表明:不同测站因接收机、天线、时钟三种设备型号不同,提取的时差值存在差异,但稳定性相当;基于载波相位观测量解算的时差结果稳定性优于伪距观测量解算的时差结果,伪距得到的时差结果万秒频率稳定度在10^(-12)~10^(-13)量级,相位得到的时差结果万秒频率稳定度在10^(-14)量级;通过单天与多天数据的时差解算结果比较,得到不同时长的时差稳定性一致. 展开更多
关键词 GPS 北斗三号全球卫星导航系统(BDS-3) 时差监测 单站空间信号法 稳定性
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A VERTICAL LAYERED SPACE-TIME CODE AND ITS CLOSED-FORM BLIND SYMBOL DETECTION 被引量:1
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作者 Zhao Zheng Yin Qinye Zhang Hong Feng Aigang (Institute of Information Engineering, Xi’an .Jiaotong University, Xi’an 710049) 《Journal of Electronics(China)》 2003年第2期102-109,共8页
Vertical layered space-time codes have demonstrated the enormous potential to accommodate rapid flow data. Thus far, vertical layered space-time codes assumed that perfect estimates of current channel fading condition... Vertical layered space-time codes have demonstrated the enormous potential to accommodate rapid flow data. Thus far, vertical layered space-time codes assumed that perfect estimates of current channel fading conditions are available at the receiver. However, increasing the number of transmit antennas increases the required training interval and reduces the available time in which data may be transmitted before the fading coefficients change. In this paper, a vertical layered space-time code is proposed. By applying the subspace method to the layered space-time code, the symbols can be detected without training symbols and channel estimates at the transmitter or the receiver. Monte Carlo simulations show that performance can approach that of the detection method with the knowledge of the channel. 展开更多
关键词 Layered space-time code Array signal processing Subspace method Blind symbol detection
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Direction-of-arrival estimation of quasi-stationary signals using two-level Khatri-Rao subspace and four-level nested array 被引量:1
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作者 李双 何为 +2 位作者 杨旭光 鲍明 王营冠 《Journal of Central South University》 SCIE EI CAS 2014年第7期2743-2750,共8页
The Khatri-Rao(KR) subspace method is a high resolution method for direction-of-arrival(DOA) estimation.Combined with 2q level nested array,the KR subspace method can detect O(N2q) sources with N sensors.However,the m... The Khatri-Rao(KR) subspace method is a high resolution method for direction-of-arrival(DOA) estimation.Combined with 2q level nested array,the KR subspace method can detect O(N2q) sources with N sensors.However,the method cannot be applicable to Gaussian sources when q is equal to or greater than 2 since it needs to use 2q-th order cumulants.In this work,a novel approach is presented to conduct DOA estimation by constructing a fourth order difference co-array.Unlike the existing DOA estimation method based on the KR product and 2q level nested array,the proposed method only uses second order statistics,so it can be employed to Gaussian sources as well as non-Gaussian sources.By exploiting a four-level nested array with N elements,our method can also identify O(N4) sources.In order to estimate the wideband signals,the proposed method is extended to the wideband scenarios.Simulation results demonstrate that,compared to the state of the art KR subspace based methods,the new method achieves higher resolution. 展开更多
关键词 difference co-array direction-of-arrival estimation Khatri-Rao product nested array
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Reconstruction algorithm in lattice-invariant signal spaces
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作者 冼军 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第7期760-763,共4页
In this paper, we mainly pay attention to the weighted sampling and reconstruction algorithm in lattice-invariant signal spaces. We give the reconstruction formula in lattice-invariant signal spaces, which is a genera... In this paper, we mainly pay attention to the weighted sampling and reconstruction algorithm in lattice-invariant signal spaces. We give the reconstruction formula in lattice-invariant signal spaces, which is a generalization of former results in shift-invariant signal spaces. That is, we generalize and improve Aldroubi, Groechenig and Chen's results, respectively. So we obtain a general reconstruction algorithm in lattice-invariant signal spaces, which the signal spaces is sufficiently large to accommodate a large number of possible models. They are maybe useful for signal processing and communication theory. 展开更多
关键词 Lattice-invariant space Reconstruction algorithm Irregular sampling
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Tourist Route Model Formulation Method Considering Spatial Reproducibility
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作者 Hiroyuki Kawai Kayoko Yamamoto 《Journal of Civil Engineering and Architecture》 2012年第9期1093-1108,共16页
This study aims to gradually reflect information concerning tourists and to propose tourist route model formulation techniques that take spatial reproducibility into account using GIS (geographic information systems... This study aims to gradually reflect information concerning tourists and to propose tourist route model formulation techniques that take spatial reproducibility into account using GIS (geographic information systems). The conclusions can be summarized into the following three points: (1) Kawagoe city in Saitama Prefecture was selected as the area targeted by this study. All types of data about Kawagoe city and tourists was collected and processed, and a tourist route model formulation method that considered spatial reproducibility using GIS was proposed, (2) 3-stage scenarios were created with the presence or absence of Kawagoe city tourist policies set as standards and this was used to develop tourist route models. It is POSsible to expect synergy in the encouragement of the use of sightseeing buses and the same traffic regulations as the traffic pilot program, and (3) It is considered that it is possible to apply the tourist route model formulation method proposed by this study to other tourist destinations without being limited by spatiotemporal differences or the particular issues of each tourist destinations as spatial reproducibility was confirmed. 展开更多
关键词 Tourist route model sightseeing spot spatial reproducibility GIS (geographic information systems) Kawagoe city.
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