A magnetic shielding
barrel noise floor evaluation method based on cross-
spectrum analysis comprises the steps of
data acquisition, simultaneous acquisition of
noise data at the central position of a magnetic shielding
barrel by using two independent atom magnetometers, windowing
processing of discretized
noise data of two channels by using a Hanning window, and reduction of near
side lobe leakage. The method comprises the following steps: windowing two-
channel data, performing
Fourier transform on the windowed two-
channel data to obtain
frequency spectrum data, and finally performing
frequency domain cross-correlation conjugate operation to calculate
frequency domain characteristics of common-mode components of the two atom magnetometers and obtain a
noise spectrum of the common-mode components of the two atom magnetometers, namely the
noise floor of the magnetic shielding
barrel. According to the method, common-mode components between the channels are extracted through cross-
spectrum analysis operation, so that the
noise floor of the magnetic shielding barrel or the
noise floor of the magnetic shielding environment is evaluated, a metering type
magnetometer with higher precision does not need to be researched, developed and used, the noise floor of the magnetic shielding barrel can be evaluated only through two magnetometers with lower sensitivity, the cost is lower, and the method is suitable for popularization and application. The equipment complexity of the extremely weak magnetic
measurement device does not need to be increased, and the credibility is high.