Influence of Temperature-Correlated Loran C Signal Propagation Delays on International Time-Scale Comparisons

The existence of a significant degree of correlation between fluctuations in the time of arrival of a Loran C signal and temperature variations at the receiving laboratory is demonstrated experimentally. These fluctuations, with periods from several days to a year, appear to constitute an important factor limiting the precision of international time-scale comparisons based on Loran C measurements, and hence both the stability and accuracy of the International Atomic Time scale at present constructed by means of these measurements.