The ionospheric oblique backscattering sounding system can not only be used to detect the state of the ionosphere and the condition of high frequency channel in real time, but also be used for over-the-horizon soundin...The ionospheric oblique backscattering sounding system can not only be used to detect the state of the ionosphere and the condition of high frequency channel in real time, but also be used for over-the-horizon sounding. Therefore, it has a very high military and civil value. For the characteristics of ionospheric oblique backscattering sounding, such as long sounding distance, wake echo, strong background noise, slow moving target, etc., a hardware platform of ionospheric oblique backscattering sounding system is designed. This platform adopts the technology of software radio and is designed as a new kind of general purpose, modularized, software-based ionosonde that is based on the VXI （Versa module eurocard eXtensions for Instrumentation） bus. This hardware platform has been successfully used in actual ionospheric oblique backscattering sounding, and the experimental results demonstrate that this system can satisfy the requirements.展开更多
On the basis of the analysis of the system sounding principle, this paper introduced a new type of ionospheric oblique backscattering sound system, which is based on the pseudo- ran- dom noise phase modulated pulse co...On the basis of the analysis of the system sounding principle, this paper introduced a new type of ionospheric oblique backscattering sound system, which is based on the pseudo- ran- dom noise phase modulated pulse compression. According to the high requirements of real-time and a large amount of computation and echo characteristics, a high-speed real-time signal processing system was established and the design of system hardware and software was focused on. The sounding results indicate that the system is equipped to handle the data fast and has a high degree of software features. It is of great significance for the realization of fast, real-time ionospheric sounding means.展开更多
基金Supported by the National Natural Science Foundation of China (40474066)
文摘The ionospheric oblique backscattering sounding system can not only be used to detect the state of the ionosphere and the condition of high frequency channel in real time, but also be used for over-the-horizon sounding. Therefore, it has a very high military and civil value. For the characteristics of ionospheric oblique backscattering sounding, such as long sounding distance, wake echo, strong background noise, slow moving target, etc., a hardware platform of ionospheric oblique backscattering sounding system is designed. This platform adopts the technology of software radio and is designed as a new kind of general purpose, modularized, software-based ionosonde that is based on the VXI （Versa module eurocard eXtensions for Instrumentation） bus. This hardware platform has been successfully used in actual ionospheric oblique backscattering sounding, and the experimental results demonstrate that this system can satisfy the requirements.
基金Supported by the National Natural Science Foundation of China (40474066)
文摘On the basis of the analysis of the system sounding principle, this paper introduced a new type of ionospheric oblique backscattering sound system, which is based on the pseudo- ran- dom noise phase modulated pulse compression. According to the high requirements of real-time and a large amount of computation and echo characteristics, a high-speed real-time signal processing system was established and the design of system hardware and software was focused on. The sounding results indicate that the system is equipped to handle the data fast and has a high degree of software features. It is of great significance for the realization of fast, real-time ionospheric sounding means.
文摘为了解决高速数字接收机中混频数据处理能力有限的问题,设计了基于八分圆周矢量旋转(OCVR)的高速数字正交混频器.该混频器仅通过简单二进制补码运算器和移位加法器即可实现,且不需要进行迭代运算.分析比较了常规的基于ROM架构、基于直接坐标旋转数字计算机(CORDIC)架构以及基于OCVR架构的混频器,结果显示基于OCVR的混频器拥有更高的数据吞吐量、更低的硬件资源消耗以及混频噪声小等特点.根据OCVR特性设计了武汉电离层斜向返回探测系统(WIOBSS)的中频(IF)数字接收机,该系统可以获取实时的宽带扫频后向散射电离图.实验证明该系统的探测覆盖范围已经延伸至3 000 km.
