Pacific Ocean HF Noise Distributions off Southern California

This paper presents a survey of mean-valued HF external noise figures of mean day and night noise levels and amplitude probability distributions of noise regions for four-, eleven- and twenty-seven-day - collection periods off the southern California coast. Extraction of the quasi-minimum noise (QMN) power [1] used the "median of minimums" algorithm. Results are then compared to established CCIR [2] noise categories (atmospheric, galactic, man-made/residential, rural, quiet rural) and QMN FA estimates. These empirically-derived models provide a general understanding of the reported noise levels compared to historical measurements under referenced conditions.