This report gathers together available data on measurements over long distance propagation paths in the UHF Broadcast Band made by the BBC and other UK organizations, and uses them to test the accuracy of both BBC and CCIR field strength prediction methods. The former makes use of terrain database, and the latter, as contained in CCIR Recommendations 370 and Report 239, a simple statistical approach. As to be expected, the accuracy of both methods is greater for oversea path than overland. In the latter case standard deviations are large for both methods. In some cases the discrepancy can be accounted for by local features near the receiving location but in others they cannot.

Comparisons between measurements obtained for long oversea paths over different but extensive periods of time imply that uncertainty about temporal statistics may set the limit to practicable improvements in prediction accuracy.