Ambient noise station-correlation spectra for USArray stations

A04A-TA secondary stations.

A05A-TA A06A-TA A07A-TA A08A-TA B04A-TA B05A-TA B06A-TA B07A-TA B08A-TA C03A-TA
C04A-TA C05A-TA C07A-TA C08A-TA D03A-TA D04A-TA D05A-TA D06A-TA D07A-TA E03A-TA
E04A-TA E05A-TA E06A-TA
NLWA-US