共查询到19条相似文献，搜索用时 109 毫秒
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介绍了RAIM算法中故障检测及其完好性保证的原理,采用STK仿真得到GPS和Galileo系统的卫星坐标及中国区域内的格网点坐标,结合航空用户对完好性需求,比较了GPS和Galileo系统下、不同类型导航性能需求的RAIM算法的可用性结果,分析了截止高度角、可视卫星数对故障检测可用性的影响。结果表明:当截止高度角越低、可视卫星数越多,故障检测的可用性越高;相同截止高度角条件时,Galileo系统下的RAIM可用性要高于GPS系统;单一的GPS导航系统难以满足垂直引导进近和精密进近等高等级的航空需求。 相似文献
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GPS和Galileo系统下RAIM算法可用性分析 总被引：3，自引：0，他引：3
介绍了RAIM算法中故障检测及其完好性保证的原理,采用STK仿真得到GPS和Galileo系统的卫星坐标及中国区域内的格网点坐标,结合航空用户对完好性需求,比较了GPS和Galileo系统下、不同类型导航性能需求的RAIM算法的可用性结果,分析了截止高度角、可视卫星数对故障检测可用性的影响.结果表明:当截止高度角越低、可视卫星数越多,故障检测的可用性越高;相同截止高度角条件时,Galileo系统下的RAIM可用性要高于GPS系统;单一的GPS导航系统难以满足垂直引导进近和精密进近等高等级的航空需求. 相似文献
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《武汉大学学报(信息科学版)》2020,(1)
全球导航卫星系统(global navigation satellite system, GNSS)的发展和完善为多星座融合定位、导航和授时提供了重要基础,也为接收机自主完好性监测提供了更有利的外部条件。首先通过星座仿真,分别计算了单频和双频条件下GNSS单系统及组合系统的保护水平;然后分析了全球范围内GNSS不同频率及不同组合方式条件下的保护水平的基本分布情况;最后探讨了在不同频率和组合方式条件下接收机自主完好性监测(receiver autonomous integrity monitoring, RAIM)在不同进近阶段的可用性。计算结果表明,单系统单频或双频组合均不能满足垂直制导航性能(localizer performance with vertical guidance 200ft, LPV-200)进近阶段的要求;双系统双频组合可满足LPV-200进近阶段的要求;三系统双频组合可满足具有垂直引导(approach with vertical guidance II,APV-II)的进近阶段的要求,但无法满足精密进近要求;四系统组合相比于三系统组合改善效果不明显。 相似文献
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实时精密单点定位(PPP)是一种经济高效的高精度海上定位技术。随着海上精密作业深入发展,除定位精度外,对于海上高精度位置服务的可靠性要求不断提高。精密单点定位完好性监测是海上精密作业高精度定位的可靠性保障。为此,通过构建接收机端高级自主完好性监测算法,建立严格完好性保障的海上精密单点定位误差界限,保障了海上多重干扰条件下的高精度定位可靠性性能。本文依托南海某DP动力定位钻井平台开展远海钻井作业,实测结果表明,北斗/GPS PPP收敛定位精度可达10 cm,危险误导信息概率满足10-7水平,连续性风险概率满足10-6水平。 相似文献
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根据机场实施精密导航技术（RNP）的要求,国际民航组织（ICAO）提出地基增强系统（GBAS）,GBAS必将成为未来发展的必然趋势。但是在复杂的机场环境下,卫星信号易受外界影响和干扰,连续性不足,进而影响GBAS系统完好性性能的实施。因此,本文提出了伪卫星与北斗卫星联合定位增强GBAS的方法,并从加入伪卫星后的精度因子（DOP）、多参考一致性检测（MRCC）、完好性等方面进行了对比仿真分析。仿真结果表明,增加伪卫星后的系统精度因子得到了明显改善（PDOP小于3）,同时提高了完好性性能,能够为复杂环境下的机场提供GBAS CAT Ⅱ类及以上等级的精密进近服务。 相似文献
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张倩倩 《测绘科学技术学报》2015,(5):455-459
讨论了如何提高单星座增强型接收机自主完好性监测ARAIM算法的可用性问题。借助于钟差辅助模型设计了一种能够用于垂直精密进近LPV-250服务的单星座ARAIM算法。将钟差预测值作为虚拟伪距观测值纳入到当前的定位解算中,以提高单星座ARAIM算法的可用性。设计了新的完好性风险配置方案,在计算用户保护水平时,通过直接计算故障偏差对定位误差的影响大小来解决未知故障偏差的估计问题,对于系统的可用性给出了更精确的评定。试验分析结果表明,钟差辅助对于提高单星座ARAIM算法的可用性具有显著的作用。 相似文献
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针对导航卫星在区域完好性监测网可视弧段之外难以实现基于地面监测站的系统级完好性监测问题,提出一种基于星间链路辅助支持的导航卫星自主完好性监测方法。该方法通过利用星间组合观测值,分离星钟误差和星历误差,采用基于平稳时间序列的非稳态异常检测算法对导航卫星星载原子钟相位抖动及频率的异常漂移进行监测;采用基于轨道先验信息的非中心化开方分布异常检测算法对轨道异常机动进行监测,并利用星间链路组合观测量对卫星自主完好性监测及其对全球用户完好性性能的提升作用开展仿真分析与研究。仿真计算结果表明:该方法可以在地面监测网不可视弧度内有效减小空间段卫星部分的故障漏检概率以及系统完好性风险,缩短完好性告警时间,提高全球卫星导航系统的完好性服务水平。 相似文献
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Approach service type D evaluation of the DLR GBAS testbed 总被引：3，自引：2，他引：1
Ground-based augmentation systems (GBAS) for satellite navigation are intended to replace the instrument landing system for precision approach of aircraft into an airport in the near future. Here, we show an evaluation of data collected during flight trials with the GBAS testbed of the German aerospace center with respect to requirements for the GBAS approach service type D. This service will permit approach and landing down to the zero visibility conditions of category IIIc approaches. We show output of all airborne monitors and the results of an integrity analysis. During all flight trials, the system performed within the required criteria for integrity, continuity, and availability. 相似文献
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利用GALILEO全球监测网络和中国地壳运动监测网络分别对GALILEO系统完备性指标SISMA进行仿真计算。结果表明,全球完备性监测SISMA结果不稳定,随地理位置的变化较大,不能满足局部地区的生命安全服务要求;利用适当布设的局域监测网络进行的SISMA局域监测数值稳定,变化较小,结果明显优于全球SISMA监测结果,可以满足生命安全服务要求,可信度达到100%。在我国进行局域SISMA监测,是对全球完备性监测进行的有效和必要补充,提高系统的可用性和定位可信度。 相似文献
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Global navigation satellite system (GNSS)-based attitude determination has been widely used in the navigation fields. The reliability of attitude determination is indispensable for safety-critical applications. Since the multi-antenna-based attitude determination uses ultra-short baseline carrier phase double differential processing, the incorrect ambiguity resolution and the excessive measurement error are two main factors affecting the reliability of attitude determination. Since the ambiguity correctness validation cannot guarantee the reliability of the attitude solution, therefore an integrity monitoring method is proposed for the attitude determination in the measurement domain. The proposed integrity monitoring method constructs double test statistics to satisfy the requirements of integrity risk and continuity risk, simultaneously. Furthermore, the attitude alarm limit has been derived from the required navigation performance as the threshold to test the availability of attitude determination. The performance of the proposed method is tested by conducting the static and kinematic experiments, respectively. The static results have shown that the proposed integrity monitoring method is able to monitor the ambiguity fault and the excessive measurement noise. The real-world kinematic data have indicated that the proposed method can reduce the maximum attitude error by about 2.3°, when compared with the standalone ratio-test method. 相似文献
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In this paper, we present the development of a local area differential GPS testbed of the ground-based augmentation system (GBAS) as the future airport navigation facility in the Taipei Flight Information Region (FIR) in Taiwan. The testbed is mainly a GBAS ground facility, which consists of a ground station, three GBAS receivers, and a VDL (VHF data link) broadcast antenna. We also present an airborne GPS/GBAS prototype receiver in this paper. The airborne subsystem (a GPS/GBAS receiver) receives the correction messages from the ground subsystem to perform a differential GPS (DGPS) positioning. In order to provide an ILS-look-alike approach and landing, the output messages of the airborne receiver are packed in an ARINC 429 format. The proposed airborne system has a software-based global navigation satellite system (GNSS) receiver structure. 相似文献
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北斗全球卫星导航系统(简称北斗三号系统,BDS-3)的建设对拓展全球卫星导航系统(global navigation satellite system, GNSS)的应用有重要作用,为多星座融合定位、导航和授时提供了重要支持。多系统融合定位给用户提供了更多的导航信息源,也为导航卫星系统完好性和用户自主完好性指标的实现提供了新的保障。然而多卫星组合的使用显著增加了观测冗余信息,由此提出一种基于抗差估计的保护水平重构方法,利用抗差估计方法及其参数验后信息,重新估计用户保护水平。利用GPS/BDS组合数据进行计算分析,实验结果表明,该方法可在保障特定要求定位精度的前提下,降低告警频率。 相似文献
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中国独立发展的北斗系统已经具备亚太地区的定位导航能力,为研究以北斗系统为主的车载导航技术的应用精度,采用伪距单点定位的方法分别对车载GPS,BD2,GPS\BD2 3种导航模式下的二维导航精度进行对比分析,结果显示定位精度分别为:3.66m,4.76 m,3.01 m,可以看出基于单点定位的北斗二维平面导航精度已达到5 m内,完全满足大众日常的出行要求。组合系统与GPS导航系统对比,组合系统具有更高的精度,是较好的导航模式。并基于visual studio平台编写定位软件,实现对车辆位置和速度信息的提取,监控车辆是否超速。 相似文献
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中国区域导航定位系统(CAPS)是我国一种具有自主知识产权的新型卫星导航系统.基于卫星转发地面产生的导航信号的工作模式,实现卫星导航功能.导航综合基带是CAPS主控站的重要终端设备.利用无线电软件设计思想,设计了导航综合基带总体架构.采用标准面向仪器系统的PCI扩展(PXI)机箱结构,基于总线设计,可扩展性强.基带的关键技术包括发射信号的频率补偿技术,高精度接收技术,设备高稳定时延保持技术.实际测试结果表明:该导航综合基带性能良好,伪码测量精度优于0.20 ns,通道时延稳定度优于0.25 ns,频率补偿精度优于0.8 Hz,满足CAPS的需求. 相似文献
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GPS/INS navigation precision and its effect on airborne radio occultation retrieval accuracy 总被引：1，自引：1，他引：0
Paytsar Muradyan Jennifer S. Haase Feiqin Xie James L. Garrison Justin Voo 《GPS Solutions》2011,15(3):207-218
An airborne radio occultation (RO) system has been developed to retrieve atmospheric profiles of refractivity, moisture, and temperature. The long-term objective of such a system is deployment on commercial aircraft to increase the quantity of moisture observations in flight corridors in order to improve weather forecast accuracy. However, there are several factors important to operational feasibility that have an impact on the accuracy of the airborne RO results. We investigate the effects of different types of navigation system noise on the precision of the retrieved atmospheric profiles using recordings from the GNSS Instrument System for Multistatic and Occultation Sensing (GISMOS) test flights, which used an Applanix POS/AV 510 Global Positioning System (GPS)/Inertial Navigation System (INS). The data were processed using a carrier phase differential GPS technique, and then the GPS position and inertial measurement unit data were combined in a loosely coupled integrated inertial navigation solution. This study quantifies the velocity precision as a function of distance from GPS reference network sites, the velocity precision with or without an inertial measurement unit, the impact of the quality of the inertial measurement unit, and the compromise in precision resulting from the use of real-time autonomous GPS positioning. We find that using reference stations with baseline lengths of up to 760?km from the survey area has a negligible impact on the retrieved refractivity precision. We also find that only a small bias (less than 0.5% in refractivity) results from the use of an autonomous GPS solution rather than a post-processed differential solution when used in an integrated GPS/INS system. This greatly expands the potential range of an operational airborne radio occultation system, particularly over the oceans, where observations are sparse. 相似文献