Automatic scaling of HF swept-frequency backscatter ionograms

作者：Song Huan; Hu Yaogai^*; Jiang Chunhua; Zhou Chen; Zhao Zhengyu

来源：Radio Science, 2015, 50(5): 381-392.

DOI：10.1002/2014RS005621

• low power
• backscatter ionograms
• automatic scaling
• mode recognition
• leading edge extraction

This paper describes a method for automatically scaling HF swept-frequency backscatter ionograms, which can be applied to a low-power oblique backscatter sounding system. Based on the information of vertical echo in the ionogram, propagation mode is recognized from the amplitude differences between E layer and F layer echoes. Points on the leading edge are extracted by using minimum group path delay theory. The spurious points are removed by using residual analysis. A multiple linear polynomial was adopted to fit the extracted leading edge points. Smooth fitting curves can then be obtained. Automatic scaling results from 362 ionograms show that the proposed method can efficiently recognize propagation modes and extract leading edge curves by taking full advantages of echo characteristics and echo amplitudes in the ionograms. This novel method can be applied into real-time backscatter ionogram scaling, which facilitates the extensive usage of oblique backscatter soundings.

• 出版日期2015-5
• 单位武汉大学