For example, a given excursion or event 
will appear to arrive at different times 
at each of the components on one station. 
On another station the time displace- 
ments will usually be distributed quite 
differently among components. These 
displacements are often a significant 
proportion of the signal period. Hence 
it is difficult to determine the absolute 
time of the commencement or peak of an 
event. Correlation techniques on the 
total "pulsating magnetic field" may be 
used in some cases to minimize the un- 
certainty. 
REFERENCES 
1. "The Low Frequency Electromagnetic 
Detector-Amplifier System Used During 
PNL Field Operation at S.E.S., June, 
1960", by D.J. Evans, PNL Laboratory 
Note 60-11, July 1960. 
2. "The Pacific Naval Laboratory - 
Stanford University Conjugate Point 
Experiment", by D.J. Evans, S. Horner, 
J.E. Lokken, J.A. Shand and 
C.S. Wright, PNL Laboratory Note 
60-41, December 1960. 
3. "Measurement of the Vertical Com- 
ponent of Magnetic Micropulsations 
in the 2 to 40 cps Band", by 
D.J. Evans, PNL Laboratory Note 
60-34, November 1960. 
4. Private communication from K. Vozoff, 
University of Alberta. 
333 
