搜索结果: 1-15 共查到“信息与通信工程 GNSS”相关记录25条 . 查询时间(0.035 秒)
蒸发波导对GNSS海面反射信号有效散射区域的影响
蒸发波导 GNSS海面反射信号 射线追踪 有效散射区域
2019/2/27
蒸发波导在海洋低空的发生概率高达90%，对舰船雷达、通信等电磁系统具有重要影响.为了分析利用GNSS卫星海面反射信号的时延-相关功率波形反演蒸发波导的可行性，本文提出了GNSS卫星海面反射信号的有效散射区域的概念，并将有效散射区域内的GNSS反射信号区分为GNSS标准反射信号和GNSS波导反射信号；然后，利用射线追踪方法，仿真分析了GNSS卫星海面反射信号的有效散射区域大小对蒸发波导的关键参数——...
基于值域的GNSS姿态测量改进算法研究
整周模糊度 姿态测量 值域 基线约束
2016/5/11
针对基于值域的全球卫星导航系统（GNSS, global navigation satellite system）姿态测量方法没有考虑搜索域相关性而造成初始化时间长、搜索范围大的问题，提出了一种模糊度反约束值域搜索的改进方法。首先推导了固定基线长度条件下模糊度搜索空间，然后利用较小的2个搜索空间及其与俯仰角、航向角的关系重新确立了二维搜索域组合，最后根据值域搜索在基线二次残差最小情况下确定整周模糊...
高动态GNSS信号多普勒模拟任意阶DDS合成器设计
高动态 GNSS信号 多普勒 任意阶DDS
2016/5/30
为高精度模拟高动态条件下GNSS信号的多普勒特性，本文提出一种任意阶DDS信号合成器的设计方法。设计了任意阶DDS信号合成器的结构；通过理论分析，推导了各级累加器相位初值的计算公式；给出了字长选择方法；经仿真与验证，该方法能精确模拟GNSS信号的多普勒特性。此外，本文提出的DDS设计方法不受阶数的限制，可普遍应用于各类信号模拟器的设计。
高动态GNSS信号多普勒模拟任意阶直接数字合成器设计
高动态 GNSS信号 多普勒 任意阶直接数字合成
2016/7/13
为高精度模拟高动态条件下GNSS信号的多普勒特性，提出一种任意阶直接数字合成信号合成器的设计方法。设计任意阶直接数字合成信号合成器的结构；通过理论分析，推导各级累加器相位初值的计算公式；给出字长选择方法。经仿真验证，该方法能精确模拟GNSS信号的多普勒特性。此外，提出的直接数字合成器设计方法不受阶数的限制，可普遍应用于各类信号模拟器的设计。
基于天线阵方位变化的相位双差GNSS欺骗干扰检测算法研究
载波相位双差 GNSS欺骗干扰检测 方位变化 天线阵
2016/5/30
GNSS欺骗干扰通常由单个天线发射,各个欺骗干扰信号到达接收机的角度相同,采用阵列天线接收时欺骗信号达到不同阵元的相位差包含了其角度信息,故可利用信号载波相位差进行欺骗干扰检测。相位双差检测算法通过比较不同卫星信号到达天线阵两阵元的相位差实现欺骗干扰的判别,但对于二元天线阵,其载波相位双差存在角度模糊,导致虚警概率较高,限制了算法的应用。针对这一问题,本文提出了基于天线阵方位变化的欺骗干扰检测算法...
Adjustment and transformation strategies of ItalPoS Permanent GNSS Network
GNSS Permanent Network Globk Adjustment Strategies Boucher Altamimi transformation
2015/8/28
A private network of 133 Global Navigation Satellite Systems (GNSS) permanent sites, named ItalPoS (Italian Positioning Service) and uniformly covering the entire Italian territory, was established in...
The Effects of the Ionosphere and C/A Frequency on GPS Signal Shape:Considerations for GNSS-2
Effects Ionosphere C/A Frequency GPS Signal Shape Considerations
2015/6/29
By greatly increasing the chipping rate of the pseudo random noise (prn) code, it may be possible to measure the ionosphere (TEC) in near real time, by exploiting the dispersive nature of the ionosphe...
Effects of Signal Deformations on Modernized GNSS Signals
Signal Deformation Modernized GNSS Signals
2015/6/26
Satellite-based navigation requires precise knowledge of the structure of the transmitted signals.For GPS, accurate knowledge of the shape of the code correlation peaks is required to ensure no biases...
Multiple constellations and modernized GNSS signals promise to bring a wealth of ranging possibilities to navigation users. They offer improved geometry and redundancy, immunity to ionospheric errors,...
Wideband signals show promise for Galileo development and GPS modernization because they provide sharper correlation peaks and thus more accuracy.
Validation of Multiple Hypothesis RAIM Algorithm Using Dual-frequency GNSS Signals
RAIM Algorithm Dual-frequency GNSS Signals
2015/6/25
A Multiple Hypothesis Solution Separation (MHSS) RAIM algorithm was developed at Stanford in recent years, with the purpose of meeting the stringent integrity requirements imposed by the Federal Aviat...
Bounding Errors Caused by Nominal GNSS Signal Deformations
Bounding Errors Caused Nominal GNSS Signal Deformations
2015/6/24
Nominal signal deformations are present in GNSS-GPS and WAAS-GEO satellite signals. They result in pseudorange errors, which in turn cause navigation errors for GNSS users. These navigation errors dep...
Determining the guidance system accuracy with the support of a large GNSS dataset
off -track error geometry rectangular coordinate system SJTSK
2014/2/24
Several methods are used presently to assess the accuracy of machinery guidance systems. However, these off er a
limited number of records and are time and cost consuming. As the machinery is ...
Determining the guidance system accuracy with the support of a large GNSS dataset
track error geometry rectangular coordinate system SJTSK
2014/2/24
Several methods are used presently to assess the accuracy of machinery guidance systems. However, these off er a
limited number of records and are time and cost consuming. As the machinery is ...