Exploring the Applicability of Three Popular Models for Predicting the Received Field Strength of HF Sky‐Wave Propagation and Communication

Abstract

High‐frequency (HF) radio signals rely on ionospheric reflection and refraction to enable long‐range and transcontinental transmission, making them essential for military command, emergency response, and strategic communications. The received field strength is a key parameter for quantifying propagation conditions and optimizing HF circuit design and application. To seek the optimal model and its improvement method, therefore, this study evaluates the prediction performance of three models (REC533, ICEPAC, and VOACAP) using the Consultative Committee on International Radio (CCIR) data set and the International Telecommunication Union (ITU) recommended standardized procedure. The assessment covers multiple dimensions, including time, distance, operating frequency, season, solar activity, and the midpoint position of the path. The results show that REC533 achieves the best overall performance, exhibiting a near‐zero bias of 0.28 dB(μV/m) and the lowest standard deviation of prediction errors, 9.81 dB(μV/m), together with consistently high stability across all propagation scenarios. In contrast, ICEPAC and VOACAP exhibit systematic underestimation of approximately 4 dB(μV/m), with substantially larger dispersion exceeding 15 dB(μV/m), particularly for long‐distance circuits, at high frequencies, and in low‐latitude regions. These findings clarify the applicability and limitations of the three prediction models, provide quantitative guidance for HF spectrum planning, circuit design, and emergency communication support, and offer directions for future model refinement.