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在"导航战"的背景下,欺骗干扰效能直接关系到被保护目标的生存概率及装备实施欺骗的成功概率。但影响因素的随机性和模糊性、评估聚焦点的忽大忽小及指标定权方法主观性强的问题,均抑制了效能评估的有效开展。基于此,提出了基于云模型的GNSS欺骗干扰效能评估方法。首先建立了效能评估的定性指标体系;其次将定性指标转化为可量化的对应指标,以利用主客观融合的方法对其进行定权;最后结合权值,利用云模型将专家对指标的模糊语言评估进行定量转换得到评估值。通过实例分析,验证了本文提出的方法能够有效削弱评估存在的问题。 相似文献
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针对GNSS卫星轨道数据受到摄动力的影响产生偏差的现象,研究轨道扰动对卫星可见性的影响.借助STK(Satellite Toolkit)仿真软件,结合TowBoday、J2、J4和HPOP四种轨道预报模型对卫星轨道进行仿真研究;选取TowBoday、J2和HPOP三种模型对星座系统仿真,生成地面测控站对星座卫星的可见性分析报告.仿真结果表明:摄动力会对卫星轨道产生扰动;引入摄动力的轨道方程能解算出更为准确的轨道根数;HPOP模型能更为精确地进行卫星轨道的预报,在该模型下,纬度和经度方向上的最大误差分别为0.076°和0.115°,径向方向上高度最大误差为3.226 km;卫星轨道的扰动对卫星可见性产生一定的影响,最大误差为9.913 s. 相似文献
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欺骗干扰是全球卫星导航系统(GNSS)发展面临的重要挑战,针对小时延场景下欺骗干扰参数估计方法计算量大的问题,提出了一种基于牛顿迭代法的参数估计方法. 该方法以码相位估计为核心,通过构建欺骗场景下信号参数的非线性估计模型,采用牛顿迭代法对信号码相位进行估计,在此基础上采用最小二乘法对信号幅度和载波相位进行估计. 实验结果表明:该方法的平均迭代次数在10次左右,相比于传统参数估计方法,算法有效性大幅提升. 在准确性方面,该方法能够有效提高小时延场景下的信号参数估计精度. 相似文献
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GNSS水汽层析技术在中小尺度灾害性天气的监测和预警中发挥着重要作用。常见的GNSS水汽层析技术在垂直分层时采用均匀分层,不符合大气水汽在垂直方向上的实际分布情况。本文以大气水汽密度为依据,提出一种自适应非均匀指数分层方法。该方法大大降低了各层之间的水汽密度差异,提高了水汽层析模型分层精度,且能够实现对任意给定层析区域的自适应分层建模。利用2019年8月香港CORS实测数据和探空数据对该方法进行试验与分析,与传统均匀分层相比,自适应非均匀指数分层的均方根误差和平均绝对误差分别降低了0.401 g/m3和0.223 g/m3,在低海拔处和恶劣天气下层析结果的精度和质量显著提高。 相似文献
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针对车载移动测量系统对运动载体姿态的确定,研究车载全球卫星导航系统(GNSS)天线阵列定姿方法,分析直接法和最小二乘法定姿的姿态解算公式,并进行GNSS天线阵列车载实验.为得到两种定姿方法的精度,在不同软件定位模式解算的基础上,利用直接法和最小二乘法进行了姿态解算.实验和分析结果表明:四天线阵列最小二乘法定姿精度优于三天线阵列直接法,可靠性更高;在所有组合中,基于Moving-base定位模式的四天线阵列最小二乘法定姿精度最高,其航向角、俯仰角和横滚角精度分别可达0.066 0°、0.168 4°和0.267 8°. 相似文献
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针对GNSS多天线转发式欺骗干扰在实际应用中,当干扰机与目标机距离大于一定范围时,将引起目标机钟差突跳,从而易被目标机检测和识别的缺陷,提出了基于干扰机阵列的转发式欺骗干扰新方法。干扰机阵列按照正六边形网型布设,可实现目标区域的无缝覆盖,并且灵活易拓展。不论目标机位于区域的任何位置,均有一个最优干扰机能够对其实施有效干扰。为了确定相邻干扰机的最优间距,本文在干扰机阵列不同间距下对具有钟差突跳自适应检测能力的目标机的干扰有效性进行了仿真研究。结论表明,综合考虑各种约束因素,相邻干扰机最优间距为17 km,满足该条件的干扰机阵列在实施欺骗干扰过程中,不会造成目标机钟差突跳,有效解决了该干扰方式易被目标机识别的问题。 相似文献
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A new method for three-carrier GNSS ambiguity resolution 总被引:2,自引:2,他引:0
U. Fernández-Plazaola T. M. Martín-Guerrero J. T. Entrambasaguas 《Journal of Geodesy》2008,82(4-5):269-278
A new method for resolving the carrier-phase integer ambiguity in Global Navigation Satellite Systems (GNSS) is presented:
the MOdified Cholesky factorization for Ambiguity (MOCA) resolution. The characteristics and features of this method are described
and results obtained using a software simulator and an emulator are presented to validate its efficiency. The results are
then compared to those obtained using another existing method and good performance of the MOCA method in new GNSS systems
is shown. Furthermore, the proposed method yields accurate results even when short time spans are used or when there are poor
estimations of measurement error, making it immune to non-ideal conditions and ultimately a practical solution for real applications. 相似文献
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全球卫星导航系统(GNSS)目前得到了十分广泛的应用,但是GNSS信号到达地面的功率很低,同时民用信号的格式是公开的,因此极易受到各种无意和人为故意的干扰,会对GNSS定位和授时的精度造成影响.查找和消除干扰源十分重要,目前通用的干扰源查找手段是采用测向设备实现干扰源的交叉定位,但在不知道GNSS干扰源的大致位置时,采用测向设备查找干扰源将耗费很长的时间.如果能够通过提取一些通用接收机的输出量实现干扰源的粗定位,就可以为测向定位提供初始参考位置和大概的查找范围.本文利用几乎所有的通用接收机都能输出的位置信息实现干扰源的粗定位,随着GNSS接收机逼近干扰源,会造成接收机位置信息的丢失,随着GNSS接收机远离干扰源,接收机又会重新获取位置信息,本文利用一定区域内众多受干扰的接收机的位置信息丢失点和位置信息重捕获点来实现干扰源的粗定位.通过仿真验证,分析了该技术的定位误差,仿真结果表明,该方法能够实现GNSS干扰源的粗定位,为进一步准确查找干扰源提供位置参考. 相似文献
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Multipath interference mitigation in GNSS via WRELAX 总被引:1,自引:0,他引:1
In order to suppress the multipath interference in global navigation satellite system, two algorithms based on NLS (nonlinear least square) parameter estimation are proposed. Instead of the classic delay lock loop, the first proposed algorithm estimates the parameters of the line of sight signal and the multipath interference in the correlation domain. The NLS cost function is solved by WRELAX (weighted Fourier transform and RELAXation), which decouples the multidimensional optimization problem into a sequence of one-dimensional optimization problems in a conceptually and computationally simple way. In order to further reduce the complexity, the second NLS algorithm utilizing the characteristic of the C/A code is proposed, which estimate the parameters in the data domain. Finally, the two proposed algorithms are compared with the existing multipath interference methods and show excellent performance and less computational burden. 相似文献
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A low-complexity time-domain approach for global navigation satellite systems is proposed to detect and identify single-tone, multi-tone, swept continuous wave interference (CWI) and band-limited white Gaussian noise (BLWN). An adaptive notch filter and adaptive cascading filter structure are employed to identify the type of interference signals. The number of the cascading stages is selected by comparing the total power in receiver bandpass, and after, passing the adaptive notch filter. For this reason, the proposed filter structure is more efficient in identifying and mitigating interference signals than the conventional filter structure. In addition, the automatic gain control gain is used to detect the existence of continuous wave interference. The performance of the interference detection and identification method is evaluated for the cases of GPS signal in the presence of single-tone, multi-tone, swept CWI and BLWN. 相似文献
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针对GNSS接收机检定费用较高、检定机构数量少且检定周期长的问题,该文提出了一种简易快速的GNSS接收机检定方法。该方法根据GNSS接收机天线相位中心的几何关系,通过自设简易检定场,利用相对定位法及超短基线法分别检测接收机天线的相位中心偏差和内部噪声水平,并编写了相应的计算程序对检测数据进行快速的处理。4次独立实验结果表明:该文实验方案具有较高的精度和可靠性,适用于快速对GNSS接收机天线相位中心偏差和内部噪声水平进行自检。 相似文献
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Dezhong Chen Shirong Ye Wei Zhou Yanyan Liu Peng Jiang Weiming Tang Bing Yuan Lewen Zhao 《GPS Solutions》2016,20(3):439-450
The difficulty to detect and repair cycle slip of carrier phase measurements is a key limit for continuously high accuracy of GNSS positioning and navigation services. We propose an automated cycle slip detection and repair method for data preprocessing of a CORS network. The method jointly uses double-differenced (DD) geometry-free (GF) combination and ionospheric-free observation corrected for the computed geometrical distance (IF-OMC) to estimate the cycle slips in dual-frequency observations. The DD GF combination, which is only affected by the ionospheric residual, can be used to detect cycle slips with high reliability except for special pairs such as (77, 60) on GPS L1/L2 frequencies. The detection principle of the IF-OMC observable is such that there is a large discontinuity related to the previous epoch when cycle slips occur at the present epoch. The disadvantages of these two combinations can be overcome employing the proposed detection method. The cycle slip pair (77, 60) has no effect on the GF combination, while a change of 14.65 m is derived from GPS L1/L2 observations using the IF-OMC algorithm. Using pre-determined station coordinates as precise values, we found that the accuracy of the DD IF-OMC combination was 18 mm for a 200-km CORS baseline. Therefore, cycle slips in dual-frequency observations can be correctly and uniquely determined using DD GF and IF-OMC equations. The proposed method was verified by adding simulated cycle slips in observations collected from the CORS network under a quiet ionosphere and shown to be effective. Moreover, the method was assessed with observations made during intense ionospheric activity, which generated extensive cycle slips. The results show that the algorithm can detect and repair all cycle slips apart from two exceptions relating to long data gaps. 相似文献