The Measurement of Power Spectra from the Point of View of Communications Engineering - Part I

The measurement of power spectra is a problem of steadily increasing importance which appears to some to be primarily a problem in statistical estimation. Others may see it as a problem of instrumentation, recording and analysis which vitally involves the ideas of transmission theory. Actually, ideas and techniques from both fields are needed. When they are combined, they provide a basis for developing the insight necessary (i) to plan both the acquisition of adequate data and sound procedures for its reduction to meaningful estimates and (ii) to interpret these estimates correctly and usefully. This account attempts to provide and relate the necessary ideas and techniques in reasonable detail. Part II of this article will appear in the March issue of T H E J O U R N A L . TABLE OF CONTENTS P A R T I -- GENERAL DISCUSSION 1. I n t r o d u c t i o n 2. Autocoviiriaiice F u n c t i o n s and Power S p e c t r a 3. The Practical Situation CONTINUOUS RECORDS OF FINITE LENGTH 187 193 195 4. 5. 6. 7. 8. 9. 10. 11.