Mixed-path trans-horizon UHF measurements for P.1546 propagation model verification

An extensive propagation measurement survey was performed between The Netherlands and the United Kingdom. Seven mixed land/sea paths were monitored simultaneously, with path lengths ranging from 55 to 370 km. Eight frequencies between 500 and 700 MHz were used. Over 21 million measurements were collected during 500 days. This paper describes the survey and actions taken to assure high data quality. Detailed results are provided and can be used as propagation model test vectors. These results are compared with predictions of the ITU-R Rec. P.1546-4 propagation model. The results are disappointing: differences of up to 20 dB are found. Suggestions are made for improvement of the model.