School of Electronic Information, Wuhan University, Wuhan 430072, China.
Sensors (Basel). 2019 Feb 14;19(4):779. doi: 10.3390/s19040779.
In this paper, complete complementary code (CCC) sequences are applied to a High Frequency (HF) ionospheric sounding network. Ionosondes distributed at multiple locations use the mutually orthogonal CCC sequences to conduct vertical soundings synchronously. At the same time, thanks to the omnidirectional antennas, every station can receive the oblique echoes transmitted from the others. Due to the orthogonality between the code sequences, both vertical and oblique ionograms can be simultaneously obtained and completely separated. Through this method, the sounding efficiency can be enhanced, and the inversion difficulty can be reduced. Further, by using the data assimilation method, vertical and oblique sounding results can be combined to obtain a wide range of regional ionospheric characteristics. To verify the performance of this kind of sounding network, validation experiments are implemented to demonstrate that vertical and oblique ionograms can be obtained independently at the same time and inverted separately and that the maps of foF2 parameters obtained by using the data assimilation method provide more details than single vertical or oblique sounding.
本文将完全互补码（CCC）序列应用于高频（HF）电离层探测网络。分布在多个位置的电离层探测仪使用相互正交的 CCC 序列同步进行垂直探测。同时，由于全向天线的存在，每个站都可以接收到来自其他站的斜向回波。由于码序列的正交性，垂直和斜向的电离图可以同时获得并完全分离。通过这种方法，可以提高探测效率，降低反演难度。此外，通过使用数据同化方法，可以将垂直和斜向探测结果结合起来，获得大范围的区域电离层特性。为了验证这种探测网络的性能，进行了验证实验，结果表明可以独立获得垂直和斜向电离图，并分别进行反演，并且使用数据同化方法获得的 foF2 参数图比单一的垂直或斜向探测提供了更多的细节。
