利用電離層斜向探測系統分別對三條短波路徑進行了時延測試，在單模傳播數據曲線擬合的基礎上，計算了短波信道頻率相對時延值，重點分析了電離層單模傳播情況下頻率相對時延與頻率間隔、傳播路徑及工作頻率的變化特征。分析表明短波跳頻系統在單模工作時，中午時段的頻率相對時延最大，跳頻頻點間隔越小、路徑越大頻率相對時延的影響越小。
關 鍵 詞 短波; 斜向探測; 單模傳播; 頻率相對時延

Abstract This paper presents the results of HF channel time delay measurements on 580 km, 940 km and 1 380 km paths using oblique ionospheric sounder equipment, and gives a curve fitting data processing methods to deal with measurements data of single mode. The variety characteristics of single mode FRTD is discussed on the basis of analysis of calculating results, it indicates that the FRTD values decrease with frequency interval getting small and paths distance increasing, the maximum FRTD value in a day appears at noon.
Key words shortwave; oblique ionospheric sounder; frequency relative time delay; single mode propagation