多通道电离层探测系统数据传输设计

Design of data transmission of multi-channel ionospheric detection system

武汉大学多通道电离层探测系统是一套基于电离层地基探测的多通道探测系统,不仅可以用于常规的电离层观测,还可以用于闪电、流星的科学监测。该探测系统被大量应用于收发共站的探测场景中,并在不同的探测场景下具有不同的硬件配置。对于常规的电离层探测,发射机的功率较小;而在一些探测场景中,特别是在进行电离层斜返探测、流星探测、闪电探测时,需要功率较大的发射机(≥2 kW),在这种情况下,天线的耦合与地杂波增大,不仅会造成回波质量的下降,同时还会导致USB总线传输电路受到干扰,产生数据传输的误码与缺失。为了提高数据传输的可靠性,文中设计一套基于SDRAM和千兆以太网的多通道探测数据传输系统,实现数据的缓存与高速可靠传输,通过现场可编程逻辑门阵列(FPGA)与硬件描述语言Verilog实现SDRAM的控制与千兆以太网的数据发送,以达到提升系统的数据传输正确率的目的。实验探测结果表明,所设计系统的传输链路具有实用性和可靠性。

The multi-channel ionospheric detection system of Wuhan University is a set of multi-channel detection system based on ionospheric ground-based detection. It can not only be used for conventional ionospheric observation,but also can be used for scientific monitoring of lightning and meteors. The detection system is widely used in the detection scenario where the transceiver is co-sited,and has different hardware configurations in different detection scenarios. The power of the transmitter is small for the conventional ionospheric detection,but the high-power transmitter(>= 2 kW) is required in some detection scenarios,especially in ionospheric oblique-back detection,meteor detection,and lightning detection. In these cases,the coupling of the antenna and the increase of ground clutter will not only cause the degradation of the echo quality,but also interfere the USB bus transmission circuit,resulting in data transmission error code and missing. In order to improve the reliability of data transmission,a set of multi-channel detected data transmission system based on SDRAM and Gigabit Ethernet is designed to realize data caching and high-speed reliable transmission. The FPGA(field programmable gate array) and the hardware description language Verilog are used to realize the control of SDRAM and the data transmission of Gigabit Ethernet to improve the accuracy of data transmission of the system. The detection results in experiment show that the transmission link of the designed system has the practicability and reliability.