Today, the GNSS （global navigation satellite system） is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough a...Today, the GNSS （global navigation satellite system） is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough attention is paid to the antenna＇s setup. Usually, gross errors are found in the antenna＇s centering, leveling and in the measurement of its height, which are significant. In this paper, a thoroughly analysis of the above mentioned errors is carried out. The influence of these errors in the calculation of the X, Y, Z Cartesian geocentric coordinates and the ~, 2, h ellipsoid geodetic coordinates of a point P on the earth＇s surface, is analyzed and is presented in several diagrams. Also a new convenient method for the accurate measurement of the antenna＇s height is presented and it is strongly proposed. The conclusions outline the magnitude of these errors and prove the significance of the antenna＇s proper setup at the accurate GNSS applications.展开更多
文章以Java为主要编程语言,使用SSM为后端开发框架,实现对广播发射机的远程监控。监控系统使用IDEA作为开发软件,利用SQL Server 2005进行数据库开发,最终实现对广播发射机工作状态的监控。本文应用MCV模式,从前端开发、后端开发、数据...文章以Java为主要编程语言,使用SSM为后端开发框架,实现对广播发射机的远程监控。监控系统使用IDEA作为开发软件,利用SQL Server 2005进行数据库开发,最终实现对广播发射机工作状态的监控。本文应用MCV模式,从前端开发、后端开发、数据实时更新三方面进行了研究。在设计方面,针对现有的框架和算法进行改进、优化和利用,实现了一种网页终端读取数据的远程监控系统,可以更加方便快捷得到广播发射机相关状态信息。展开更多
无线通信中的天线发射功率、高度、角度和信号频率等因素对其接收信号强度(received signal strengthindication,RSSI)有很大的影响.通过大量的实验,分析探讨室内环境下天线高度对RSSI和测距精度的影响.实验结果证明,只要选择合适的天...无线通信中的天线发射功率、高度、角度和信号频率等因素对其接收信号强度(received signal strengthindication,RSSI)有很大的影响.通过大量的实验,分析探讨室内环境下天线高度对RSSI和测距精度的影响.实验结果证明,只要选择合适的天线高度,433 MHz无线信号用于室内测距是可行的.展开更多
文摘Today, the GNSS （global navigation satellite system） is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough attention is paid to the antenna＇s setup. Usually, gross errors are found in the antenna＇s centering, leveling and in the measurement of its height, which are significant. In this paper, a thoroughly analysis of the above mentioned errors is carried out. The influence of these errors in the calculation of the X, Y, Z Cartesian geocentric coordinates and the ~, 2, h ellipsoid geodetic coordinates of a point P on the earth＇s surface, is analyzed and is presented in several diagrams. Also a new convenient method for the accurate measurement of the antenna＇s height is presented and it is strongly proposed. The conclusions outline the magnitude of these errors and prove the significance of the antenna＇s proper setup at the accurate GNSS applications.
文摘文章以Java为主要编程语言,使用SSM为后端开发框架,实现对广播发射机的远程监控。监控系统使用IDEA作为开发软件,利用SQL Server 2005进行数据库开发,最终实现对广播发射机工作状态的监控。本文应用MCV模式,从前端开发、后端开发、数据实时更新三方面进行了研究。在设计方面,针对现有的框架和算法进行改进、优化和利用,实现了一种网页终端读取数据的远程监控系统,可以更加方便快捷得到广播发射机相关状态信息。
文摘无线通信中的天线发射功率、高度、角度和信号频率等因素对其接收信号强度(received signal strengthindication,RSSI)有很大的影响.通过大量的实验,分析探讨室内环境下天线高度对RSSI和测距精度的影响.实验结果证明,只要选择合适的天线高度,433 MHz无线信号用于室内测距是可行的.
