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
The geometrical theory of diffraction (GTD) ,combined with Fourier transformation, has been applied to the back - scattering on a finite - length rigid circular cylinder due to a narrow sound beam. The theoretical res...The geometrical theory of diffraction (GTD) ,combined with Fourier transformation, has been applied to the back - scattering on a finite - length rigid circular cylinder due to a narrow sound beam. The theoretical results are confirmed by the model experiment.展开更多
The real-time information of the distant ionosphere can be acquired by using the Wuhan ionospheric oblique backscattering sounding system(WIOBSS),which adopts a discontinuous wave mechanism.After the characteristics o...The real-time information of the distant ionosphere can be acquired by using the Wuhan ionospheric oblique backscattering sounding system(WIOBSS),which adopts a discontinuous wave mechanism.After the characteristics of the ionospheric echo Doppler spectra were analyzed,the signal preprocessing was developed in this paper,which aimed at improving the Doppler spectra.The results indicate that the preprocessing not only makes the system acquire a higher ability of target detection but also suppresses the radio frequency interference by 6-7 dB.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The geometrical theory of diffraction (GTD) ,combined with Fourier transformation, has been applied to the back - scattering on a finite - length rigid circular cylinder due to a narrow sound beam. The theoretical results are confirmed by the model experiment.
基金supported by the National Natural Science Foundation of China(Grant No.40474066).
文摘The real-time information of the distant ionosphere can be acquired by using the Wuhan ionospheric oblique backscattering sounding system(WIOBSS),which adopts a discontinuous wave mechanism.After the characteristics of the ionospheric echo Doppler spectra were analyzed,the signal preprocessing was developed in this paper,which aimed at improving the Doppler spectra.The results indicate that the preprocessing not only makes the system acquire a higher ability of target detection but also suppresses the radio frequency interference by 6-7 dB.
