Comparison between basic MUF calculated by ITU-R P.434 and measurements

The F₂ layer basic maximum usable frequency(MUF)value calculated by the ITU-R P.434 method is compared with the median of measurement for 10 oblique circuits in China during January and July,2011,and then the applicability of ITU-R P.434 in China area is analyzed.It is shown that the method has good applicability in China,except that sometimes there are certain error in some circuits.In January,MUF value calculated by ITU-R P.434 is less than the median of measurement by 20%~30% in mid-latitude during sunrise,while it is larger by 20%~30% during sunset.The relative difference between these two values at low-latitude is larger during mid-night,reaching about 40%.In July,the two values agree with each other quite well in all circuits,and the relative differences are among about-10%~20%.This result is valuable to HF applications such as the frequency selection.