CAS-DIS数字电离层测高仪系统研制

提出了将射频直接采样数字化的接收方式应用于数字电离层测高仪系统的设计方案, 并详细介绍了该方案在CAS-DIS (Chinese Academy of Sciences, Digital Ionosonde)电离层测高仪系统的应用, 给出了CAS-DIS电离层测高仪在中国武汉电离层探测标校试验场和武汉-北京斜向电离层探测系统中的实验结果. 观测结果表明, 采用本文提出的数字化方案设计的电离层测高仪系统性能优越, 且可以分别工作在垂直和斜向探测模式, 满足了电离层探测的多种应用需求. 

A New Design for Digital Ionosonde

In this paper a new design for digital ionosonde is presented based on the concept of directly sampling in the RF domain, and the real time digital down-conversion processing is implemented in FPGA device, which improves the signals identity of I and Q, and enhances the dynamic range of the receiver. In addition, since the digital waveform generation in transmitting path, the digital down-conversion processing in receiving path, data pre-processing, and timing control functions of the whole system are integrated in one FPGA chip, which improved the flexibility of the ionosonde. To verify the design, a high quality digital ionosonde called CAS-DIS (Chinese Academy of Sciences, Digital Ionosonde) has been developed. This paper describes the details of CAS-DIS, its main features and testing results in the ionosphere detection, including in Wuhan ionospheric sounding and calibration station and Wuhan-Beijing oblique ionospheric sounding system, and the observations show that performance of the iononsonde using the proposed design is superior, and the ionosonde can operate in both vertical and oblique sounding mode, to meet a variety of applications in ionospheric detection.