DF–variometer based on a single–component proton type absolute magnetometer

A scheme for high–precision absolute measurement of the declination angle (azimuth) and the modulus of the Earth's magnetic field using nuclear precession magnetometers, with an additional magnetic field bias system for determining the field component, is proposed. A formula for calculating the correction to the declination angle and evaluating the systematic and random error in determining the angle when specifying the direction of the base vector of the external field is presented. Good accuracy of determining the angle (on the order of tens of arc seconds) in a wide range of latitude and field variations is shown, significantly worsening in the polar latitudes and during strong magnetic storms.