A proposed automatic standard magnetic observatory

Present-day standard magnetic observatories employ an extensive amount of routine hand labor in determining absolute values of magnetic components and in scaling magnetograms. An automatic observatory is proposed in which the proton precession magnetometer is used as the detecting element. Two mutually perpendicular pairs of coils control bias fields in a plane perpendicular to the mean magnetic field vector. A preliminary calibration procedure involving reversals of the bias fields and rotations of the coil system eliminates uncertainties in coil geometry. Subsequently, measurements are automatically recorded in digital form so that a value of each magnetic component can be computed with high accuracy once a minute. The data are automatically handled in a computer to obtain all the statistical output which is typical of standard observatories.