At the beginning of 1969 an elaborate programme of E-layer drift measurements was started at De Bilt. The closely spaced receiver method is being used in combination with an on-line analogue computer which plots the polarity-, auto- and cross-correlation functions of the fading signals. The following results over 1969 and a part of 1970 are presented and discussed: mean hourly values of the N and E components for each month; harmonic analysis and prevailing winds, comparison between results obtained from the intersection of the correlation curves and from the time shifts for maximum cross-correlation; and comparison with the results from other stations at about the same latitude.
