Fig. 9
From: A Dataset of Lower Band Whistler Mode Chorus and Exohiss with Instrumental Noise Thresholds
Distribution of search coil noise for Cluster 1 STAFF-SA instrument. Percentiles of the probability distribution of the trace of the magnetic power spectral density matrix of the instrumental noise as a function of frequency \({f}_{l}\) obtained from all 27 frequency channels \(l\) of the STAFF-SA instrument onboard Cluster 1. The data were acquired during a calm interval on March 8, 2002 from 18:00 to 21:00 UT. Dotted lines show theoretical cumulative probabilities of the scaled \({\chi }^{2}\) distribution according to Eq. 3, with the root-mean-square noise level \({\sigma }_{l}^{2}\) determined using the observed median value, and with \(\nu =2\,{n}_{l}\,{n}_{a}\) degrees of freedom, where na = 3 is the number of search coil antennas, and \({n}_{l}\) is the number of onboard averaged power spectra. nl = 4 for l = 1…9, nl = 32 for l = 10…18, nl = 256 for l = 19…27. The black dotted line corresponds to P0 = 10−7 from Eqs. 3, 6.
