A Function Generator for Calibration of Electromagnetic-Field Recorders

Abstract

A low-frequency function generator for calibrating measuring channels of electromagnetic-field recorders in the frequency range from one hertz to tens of kilohertz is described. One feature of the device is the stability and high-precision phase synchronization of the output signal with a coordinated universal time provided by a GPS/GLONASS receiver. The application of the developed device made it possible to increase the accuracy of calibration of the measuring channels of receivers in a very low frequency range and, as a consequence, the accuracy of measuring the phase velocities of artificial and natural electromagnetic signals of ultralow- and very-low-frequency bands.