October 1970 | NTIA Technical Report OTS/ITS RR 2
Donald H. Zacharisen; William B. Jones
Abstract: Worldwide atmospheric noise at 1 MHz, as presented in CCIR Report 3 22 (1963), has been numerically mapped in universal time. The mapping technique and representative contour maps for January and July, are presented. Fourier analyses were performed separately on the periodic functions that represent the longitudinal and diurnal variations of the data. The latitudinal variation is represented by a weighted least-squares polynomial in the sine of the latitude. This method provides an improved numerical representation of the atmospheric noise with fewer coefficients than were required previously.
Keywords: HF propagation; ionospheric propagation; atmospheric noise; least-squares fitting; numerical maps; universal time; ionospheric predictions
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