It is an effective method to broadcast the augmentation information of satellite navigation system using GEO technology.However,it becomes difficult to receive GEO signal in some special situation,for example in citie...It is an effective method to broadcast the augmentation information of satellite navigation system using GEO technology.However,it becomes difficult to receive GEO signal in some special situation,for example in cities or canyons,in which the signal will be sheltered by big buildings or mountains.In order to solve this problem,an Internet-based broadcast network has been proposed to utilize the infrastructure of the Internet to broadcast the augmentation information of satellite navigation system,which is based on application-layer multicast protocols.In this paper,a topology and position aware overlay network construction protocol is proposed to build the network for augmentation information of satellite navigation system.Simulation results show that the new algorithm is able to achieve better performance in terms of delay,depth and degree utilization.展开更多
星基增强系统(SBAS,satellite based augmentation system)的出现可有效提升全球卫星导航系统核心星座的各项性能,因其能够产生较高精度的定位信息以提供更加安全的导航服务,被广泛应用于民航领域中。利用SBAS服务区域内不同监测站接收...星基增强系统(SBAS,satellite based augmentation system)的出现可有效提升全球卫星导航系统核心星座的各项性能,因其能够产生较高精度的定位信息以提供更加安全的导航服务,被广泛应用于民航领域中。利用SBAS服务区域内不同监测站接收的导航和增强报文等实测数据,研究了定位精度和完好性报文处理过程以及可见星质量、定位误差、保护级和告警门限等完好性参数指标。针对完好性监测所要求的故障检测能力,分析不同故障函数时卫星的完好性服务能力,最后完成SBAS故障卫星的检测与排除。结果表明:根据报文解码及各项参数提取算法能够得到较好的精度和完好性结果,各地面站精度都符合LPV-200进近时的要求;美国本土中部地区完全满足LPV-200进近的完好性服务要求,边缘地区监测站除个别时刻外均满足LPV进近的完好性服务要求;排除故障卫星后,服务性能基本与未发生故障时性能相近。展开更多
卫星导航地基增强系统(Ground Based Augmentation System,GBAS),可以提高卫星导航的精度、完好性、连续性和可用性,使飞机在复杂天气和恶劣环境下依然能够实现安全、高效的进近和着陆,满足民航精密进近和着陆引导等高精度导航需求.目前...卫星导航地基增强系统(Ground Based Augmentation System,GBAS),可以提高卫星导航的精度、完好性、连续性和可用性,使飞机在复杂天气和恶劣环境下依然能够实现安全、高效的进近和着陆,满足民航精密进近和着陆引导等高精度导航需求.目前GBAS一类精密进近(CATⅠ)服务水平已经完成验证和应用,但是其定位精度等服务水平仍不能完全满足民航需求.GBAS二类/三类精密进近(CATⅡ/Ⅲ)具有更好的服务水平,其技术和应用仍在开发验证中.为了提高民航运行效率和安全,急需开展基于CATⅡ/Ⅲ与CATⅢ的飞行校验活动.当前GBAS主要采用基于单频GPS的工作模式,在系统可用性、安全性和自主性方面非常受限,因此需要开发自主可控的兼容北斗的GBAS系统.本文设计了飞行校验方案,使用自主研制的国产GBAS设备,设计了飞行校验方案,在西安咸阳机场完成了CATⅡ/Ⅲ盲降精密进近着陆引导的GBAS飞行校验.试验结果表明:兼容北斗的国产GBAS具备支持CATⅡ/Ⅲ精密进近的能力,并且其性能远超传统仪表着陆系统(instrument landing system,ILS).这一成果的取得为我国航空运输的安全性提供了有力保障.展开更多
基金supported by National High Technical Research and Development Program of China (863 Program) under Grant No. 2009AA12Z322
文摘It is an effective method to broadcast the augmentation information of satellite navigation system using GEO technology.However,it becomes difficult to receive GEO signal in some special situation,for example in cities or canyons,in which the signal will be sheltered by big buildings or mountains.In order to solve this problem,an Internet-based broadcast network has been proposed to utilize the infrastructure of the Internet to broadcast the augmentation information of satellite navigation system,which is based on application-layer multicast protocols.In this paper,a topology and position aware overlay network construction protocol is proposed to build the network for augmentation information of satellite navigation system.Simulation results show that the new algorithm is able to achieve better performance in terms of delay,depth and degree utilization.
文摘星基增强系统(SBAS,satellite based augmentation system)的出现可有效提升全球卫星导航系统核心星座的各项性能,因其能够产生较高精度的定位信息以提供更加安全的导航服务,被广泛应用于民航领域中。利用SBAS服务区域内不同监测站接收的导航和增强报文等实测数据,研究了定位精度和完好性报文处理过程以及可见星质量、定位误差、保护级和告警门限等完好性参数指标。针对完好性监测所要求的故障检测能力,分析不同故障函数时卫星的完好性服务能力,最后完成SBAS故障卫星的检测与排除。结果表明:根据报文解码及各项参数提取算法能够得到较好的精度和完好性结果,各地面站精度都符合LPV-200进近时的要求;美国本土中部地区完全满足LPV-200进近的完好性服务要求,边缘地区监测站除个别时刻外均满足LPV进近的完好性服务要求;排除故障卫星后,服务性能基本与未发生故障时性能相近。
