TIME CORRELATIONS OF SHORT SAMPLES OF MF AND HF SIGNALS RECEIVED AT SEPARATED STATIONS.
Physical sciences research papers,
AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS
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Pulse envelopes from 1.95 MHz Loran transmitters were received at two synchronized stations 67 km apart and compared using a simple visual method to obtain arrival time differences. For a transmitter at 210 km distance the average measured groundwave arrival time difference agreed with the calculated value to within 1.3 microsec. For the skywave components from the same transmitter the average time difference changed from day to night, with typical random variations of 4 and 16 microsec, respectively. For skywaves from a transmitter at 500 km distance, observed with a different baseline orientation, the corresponding figures were 2 and 9 microsec. Brief daytime observations of the time signals from the 7.335 MHz station CHU, at 440 km distance, showed an average scatter of about 12 microsec. The data is too limited to permit any firm conclusions to be drawn about the implications of this technique to direction finding, but the magnitudes of the equivalent bearing fluctuations indicate there may be interesting possibilities in this regard. Author
- Direction Finding
- Radiofrequency Wave Propagation